diff --git a/ports/at91sam7s/Makefile b/ports/at91sam7s/Makefile
index 9a9c5cd3..c207e07d 100644
--- a/ports/at91sam7s/Makefile
+++ b/ports/at91sam7s/Makefile
@@ -61,6 +61,7 @@ DEMOSRC = ai.c \
 	bi.c \
 	bv.c \
 	device.c \
+	netport.c \
 	$(BACNET_BASIC)/tsm/tsm.c \
 	$(BACNET_BASIC)/sys/ringbuf.c \
 	$(BACNET_BASIC)/npdu/h_npdu.c \
diff --git a/ports/at91sam7s/bacnet.ewp b/ports/at91sam7s/bacnet.ewp
index 0bc6556b..1ff4a2a6 100644
--- a/ports/at91sam7s/bacnet.ewp
+++ b/ports/at91sam7s/bacnet.ewp
@@ -1108,6 +1108,9 @@
   <file>
     <name>$PROJ_DIR$\device.c</name>
   </file>
+  <file>
+    <name>$PROJ_DIR$\netport.c</name>
+  </file>
   <file>
     <name>$PROJ_DIR$\dlmstp.c</name>
   </file>
diff --git a/ports/at91sam7s/device.c b/ports/at91sam7s/device.c
index 26dc3fed..26200817 100644
--- a/ports/at91sam7s/device.c
+++ b/ports/at91sam7s/device.c
@@ -39,6 +39,9 @@
 #include "bacnet/basic/services.h"
 #include "bacnet/proplist.h"
 /* objects */
+#if (BACNET_PROTOCOL_REVISION >= 17)
+#include "bacnet/basic/object/netport.h"
+#endif
 #include "bacnet/basic/object/device.h"
 #include "bacnet/basic/object/ai.h"
 #include "bacnet/basic/object/av.h"
@@ -64,11 +67,12 @@ static struct my_object_functions {
     read_property_function Object_Read_Property;
     write_property_function Object_Write_Property;
     rpm_property_lists_function Object_RPM_List;
-} Object_Table[] = { { OBJECT_DEVICE, NULL, /* don't init - recursive! */
-                         Device_Count, Device_Index_To_Instance,
-                         Device_Valid_Object_Instance_Number,
-                         Device_Object_Name, Device_Read_Property_Local,
-                         Device_Write_Property_Local, Device_Property_Lists },
+} Object_Table[] = {
+    { OBJECT_DEVICE, NULL, /* don't init - recursive! */
+        Device_Count, Device_Index_To_Instance,
+        Device_Valid_Object_Instance_Number,
+        Device_Object_Name, Device_Read_Property_Local,
+        Device_Write_Property_Local, Device_Property_Lists },
     { OBJECT_ANALOG_INPUT, Analog_Input_Init, Analog_Input_Count,
         Analog_Input_Index_To_Instance, Analog_Input_Valid_Instance,
         Analog_Input_Object_Name, Analog_Input_Read_Property, NULL,
@@ -85,6 +89,12 @@ static struct my_object_functions {
         Binary_Value_Index_To_Instance, Binary_Value_Valid_Instance,
         Binary_Value_Object_Name, Binary_Value_Read_Property,
         Binary_Value_Write_Property, Binary_Value_Property_Lists },
+#if (BACNET_PROTOCOL_REVISION >= 17)
+    { OBJECT_NETWORK_PORT, Network_Port_Init, Network_Port_Count,
+        Network_Port_Index_To_Instance, Network_Port_Valid_Instance,
+        Network_Port_Object_Name, Network_Port_Read_Property,
+        Network_Port_Write_Property, Network_Port_Property_Lists },
+#endif
     { MAX_BACNET_OBJECT_TYPE, NULL, NULL, NULL, NULL, NULL, NULL, NULL } };
 
 /* note: you really only need to define variables for
@@ -769,7 +779,7 @@ int Device_Read_Property_Local(BACNET_READ_PROPERTY_DATA *rpdata)
             break;
         case 9600:
             apdu_len =
-                encode_application_unsigned(&apdu[0], RS485_Get_Baud_Rate());
+                encode_application_unsigned(&apdu[0], rs485_baud_rate());
             break;
         default:
             rpdata->error_class = ERROR_CLASS_PROPERTY;
@@ -896,9 +906,9 @@ bool Device_Write_Property_Local(BACNET_WRITE_PROPERTY_DATA *wp_data)
         case 9600:
             if (value.tag == BACNET_APPLICATION_TAG_UNSIGNED_INT) {
                 if (value.type.Unsigned_Int <= 115200) {
-                    RS485_Set_Baud_Rate(value.type.Unsigned_Int);
-                    status = true;
-                } else {
+                    status = rs485_baud_rate_set(value.type.Unsigned_Int);
+                }
+                if (!status) {
                     wp_data->error_class = ERROR_CLASS_PROPERTY;
                     wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
                 }
diff --git a/ports/at91sam7s/dlmstp.c b/ports/at91sam7s/dlmstp.c
index 8af419b6..f9a85aea 100644
--- a/ports/at91sam7s/dlmstp.c
+++ b/ports/at91sam7s/dlmstp.c
@@ -1396,3 +1396,13 @@ void dlmstp_get_broadcast_address(BACNET_ADDRESS *dest)
 
     return;
 }
+
+uint8_t dlmstp_max_info_frames_limit(void)
+{
+    return MSTP_PDU_PACKET_COUNT;
+}
+
+uint8_t dlmstp_max_master_limit(void)
+{
+    return 127;
+}
diff --git a/ports/at91sam7s/init.c b/ports/at91sam7s/init.c
index b50aac11..0778ef3b 100644
--- a/ports/at91sam7s/init.c
+++ b/ports/at91sam7s/init.c
@@ -21,12 +21,32 @@
 /* Include the board file description */
 #include "board.h"
 
+#if defined(__ICCARM__)
+//------------------------------------------------------------------------------
+//         Internal functions
+//------------------------------------------------------------------------------
+static void AT91F_Spurious_handler( void )
+{
+    while (1);
+}
+
+static void AT91F_Default_FIQ_handler( void )
+{
+    while (1);
+}
+
+static void AT91F_Default_IRQ_handler( void )
+{
+    while (1);
+}
+#else
 /* The following functions must be write in ARM mode this function called
  * directly */
 /* by exception vector */
 extern void AT91F_Spurious_handler(void);
 extern void AT91F_Default_IRQ_handler(void);
 extern void AT91F_Default_FIQ_handler(void);
+#endif
 
 /**----------------------------------------------------------------------------
  */
diff --git a/ports/at91sam7s/isr.c b/ports/at91sam7s/isr.c
index 9781354a..cd882c67 100644
--- a/ports/at91sam7s/isr.c
+++ b/ports/at91sam7s/isr.c
@@ -23,6 +23,8 @@
 #include "at91sam7s256.h"
 #include "isr.h"
 
+#if defined(__GNUC__)
+/* GCC */
 #define IRQ_MASK 0x00000080
 #define FIQ_MASK 0x00000040
 #define INT_MASK (IRQ_MASK | FIQ_MASK)
@@ -91,3 +93,4 @@ unsigned enableFIQ(void)
     __set_cpsr(_cpsr & ~FIQ_MASK);
     return _cpsr;
 }
+#endif
diff --git a/ports/at91sam7s/isr.h b/ports/at91sam7s/isr.h
index b8d89dfb..554894a2 100644
--- a/ports/at91sam7s/isr.h
+++ b/ports/at91sam7s/isr.h
@@ -32,6 +32,8 @@
 #include <intrinsics.h>
 #define isr_enable() __enable_interrupt()
 #define isr_disable() __disable_interrupt()
+#define __get_cpsr __get_CPSR
+#define __set_cpsr __set_CPSR
 #endif
 #if defined(__GNUC__)
 #define isr_enable() enableIRQ();enableFIQ();
diff --git a/ports/at91sam7s/main.c b/ports/at91sam7s/main.c
index 9b67ccf7..4da0b38c 100644
--- a/ports/at91sam7s/main.c
+++ b/ports/at91sam7s/main.c
@@ -133,7 +133,7 @@ static inline void bacnet_init(void)
 #if defined(BACDL_MSTP)
     uint8_t MAC_Address = 0x55;
 
-    RS485_Set_Baud_Rate(38400);
+    rs485_baud_rate_set(38400);
     dlmstp_set_mac_address(MAC_Address);
     dlmstp_set_max_master(127);
     dlmstp_set_max_info_frames(1);
diff --git a/ports/at91sam7s/netport.c b/ports/at91sam7s/netport.c
new file mode 100644
index 00000000..3a2899a6
--- /dev/null
+++ b/ports/at91sam7s/netport.c
@@ -0,0 +1,748 @@
+/**
+ * @file
+ * @author Steve Karg
+ * @date 2016
+ * @brief Network port objects, customize for your use
+ *
+ * @section DESCRIPTION
+ *
+ * The Network Port object provides access to the configuration
+ * and properties of network ports of a device.
+ *
+ * @section LICENSE
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include "bacnet/config.h"
+#include "bacnet/basic/binding/address.h"
+#include "bacnet/bacdef.h"
+#include "bacnet/bacapp.h"
+#include "bacnet/bacdcode.h"
+#include "bacnet/npdu.h"
+#include "bacnet/apdu.h"
+#include "bacnet/basic/object/device.h"
+/* MS/TP specific */
+#include "bacnet/datalink/dlmstp.h"
+#include "rs485.h"
+//#include "nvdata.h"
+/* me */
+#include "bacnet/basic/object/netport.h"
+
+/* our local object data */
+struct object_data {
+    bool Changes_Pending : 1;
+    uint8_t MAC_Address[1];
+    uint8_t Max_Master;
+    uint8_t Max_Info_Frames;
+    float Link_Speed;
+};
+
+/* this object example only supports 1 instance */
+#define BACNET_NETWORK_PORTS_MAX 1
+struct object_data Object_List[BACNET_NETWORK_PORTS_MAX];
+/* instance number - can be overridden */
+#ifndef BACNET_NETWORK_PORT_INSTANCE
+#define BACNET_NETWORK_PORT_INSTANCE 1
+#endif
+
+/* These three arrays are used by the ReadPropertyMultiple handler */
+static const int Network_Port_Properties_Required[] = { PROP_OBJECT_IDENTIFIER,
+    PROP_OBJECT_NAME, PROP_OBJECT_TYPE, PROP_STATUS_FLAGS, PROP_RELIABILITY,
+    PROP_OUT_OF_SERVICE, PROP_NETWORK_TYPE, PROP_PROTOCOL_LEVEL,
+    PROP_NETWORK_NUMBER, PROP_NETWORK_NUMBER_QUALITY, PROP_CHANGES_PENDING,
+    PROP_APDU_LENGTH, PROP_LINK_SPEED, -1 };
+
+static const int Network_Port_Properties_Optional[] = { PROP_MAC_ADDRESS,
+    PROP_MAX_MASTER, PROP_MAX_INFO_FRAMES, -1 };
+
+static const int Network_Port_Properties_Proprietary[] = { -1 };
+
+/**
+ * Returns the list of required, optional, and proprietary properties.
+ * Used by ReadPropertyMultiple service.
+ *
+ * @param object_instance - object-instance number of the object
+ * @param pRequired - pointer to list of int terminated by -1, of
+ * BACnet required properties for this object.
+ * @param pOptional - pointer to list of int terminated by -1, of
+ * BACnet optkional properties for this object.
+ * @param pProprietary - pointer to list of int terminated by -1, of
+ * BACnet proprietary properties for this object.
+ */
+void Network_Port_Property_List(uint32_t object_instance,
+    const int **pRequired,
+    const int **pOptional,
+    const int **pProprietary)
+{
+    (void)object_instance;
+    if (pRequired) {
+        *pRequired = Network_Port_Properties_Required;
+    }
+    if (pOptional) {
+        *pOptional = Network_Port_Properties_Optional;
+    }
+    if (pProprietary) {
+        *pProprietary = Network_Port_Properties_Proprietary;
+    }
+
+    return;
+}
+
+/**
+ * Returns the list of required, optional, and proprietary properties.
+ * Used by ReadPropertyMultiple service.
+ *
+ * @param pRequired - pointer to list of int terminated by -1, of
+ * BACnet required properties for this object.
+ * @param pOptional - pointer to list of int terminated by -1, of
+ * BACnet optkional properties for this object.
+ * @param pProprietary - pointer to list of int terminated by -1, of
+ * BACnet proprietary properties for this object.
+ */
+void Network_Port_Property_Lists(
+    const int **pRequired, const int **pOptional, const int **pProprietary)
+{
+    Network_Port_Property_List(
+        BACNET_NETWORK_PORT_INSTANCE, pRequired, pOptional, pProprietary);
+}
+
+/**
+ * For a given object instance-number, loads the object-name into
+ * a characterstring. Note that the object name must be unique
+ * within this device.
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  object_name - holds the object-name retrieved
+ *
+ * @return  true if object-name was retrieved
+ */
+bool Network_Port_Object_Name(
+    uint32_t object_instance, BACNET_CHARACTER_STRING *object_name)
+{
+    bool status = false;
+
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        status = characterstring_init_ansi(object_name, "NP-1");
+    }
+
+    return status;
+}
+
+/**
+ * Determines if a given Network Port instance is valid
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  true if the instance is valid, and false if not
+ */
+bool Network_Port_Valid_Instance(uint32_t object_instance)
+{
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        return true;
+    }
+
+    return false;
+}
+
+/**
+ * Determines the number of Network Port objects
+ *
+ * @return  Number of Network Port objects
+ */
+unsigned Network_Port_Count(void)
+{
+    return BACNET_NETWORK_PORTS_MAX;
+}
+
+/**
+ * Determines the object instance-number for a given 0..N index
+ * of Network Port objects where N is Network_Port_Count().
+ *
+ * @param index - 0..BACNET_NETWORK_PORTS_MAX value
+ *
+ * @return object instance-number for the given index, or BACNET_MAX_INSTANCE
+ * for an invalid index.
+ */
+uint32_t Network_Port_Index_To_Instance(unsigned index)
+{
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        return BACNET_NETWORK_PORT_INSTANCE;
+    }
+
+    return BACNET_MAX_INSTANCE;
+}
+
+/**
+ * For a given object instance-number, determines a 0..N index
+ * of Network Port objects where N is Network_Port_Count().
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  index for the given instance-number, or BACNET_NETWORK_PORTS_MAX
+ * if not valid.
+ */
+unsigned Network_Port_Instance_To_Index(uint32_t object_instance)
+{
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        return 0;
+    }
+
+    return BACNET_NETWORK_PORTS_MAX;
+}
+
+/**
+ * For a given object instance-number, returns the out-of-service
+ * property value
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  out-of-service property value
+ */
+bool Network_Port_Out_Of_Service(uint32_t object_instance)
+{
+    (void)object_instance;
+    return false;
+}
+
+/**
+ * For a given object instance-number, gets the reliability.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return reliability value
+ */
+BACNET_RELIABILITY Network_Port_Reliability(uint32_t object_instance)
+{
+    (void)object_instance;
+    return RELIABILITY_NO_FAULT_DETECTED;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Type.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return BACnet network type value
+ */
+uint8_t Network_Port_Type(uint32_t object_instance)
+{
+    (void)object_instance;
+    return PORT_TYPE_MSTP;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Number.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return BACnet network type value
+ */
+uint16_t Network_Port_Network_Number(uint32_t object_instance)
+{
+    (void)object_instance;
+    /* A Network_Number of 0 indicates that the Network_Number
+       is not known or cannot be determined. */
+    return 0;
+}
+
+/**
+ * For a given object instance-number, gets the quality property
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return quality property value
+ */
+BACNET_PORT_QUALITY Network_Port_Quality(uint32_t object_instance)
+{
+    (void)object_instance;
+    return PORT_QUALITY_CONFIGURED;
+}
+
+/**
+ * For a given object instance-number, loads the mac-address into
+ * an octet string.
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  mac_address - holds the mac-address retrieved
+ *
+ * @return  true if mac-address was retrieved
+ */
+bool Network_Port_MAC_Address(
+    uint32_t object_instance, BACNET_OCTET_STRING *mac_address)
+{
+    (void)object_instance;
+    Object_List[0].MAC_Address[0] = dlmstp_mac_address();
+
+    return octetstring_init(mac_address, Object_List[0].MAC_Address, 1);
+}
+
+/**
+ * @brief For a given object instance-number, set the mac-address and length
+ * @param  object_instance - object-instance number of the object
+ * @param  mac_src - holds the MAC address to be written
+ * @param  mac_len - number of bytes in the MAC address
+ * @return  true if object-name was set
+ */
+bool Network_Port_MAC_Address_Set(
+    uint32_t object_instance, uint8_t *mac_src, uint8_t mac_len)
+{
+    if (mac_len == 1) {
+        Object_List[0].MAC_Address[0] = mac_src[0];
+        Object_List[0].Changes_Pending = true;
+        return true;
+    }
+
+    return false;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Number.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return APDU length for this network port
+ */
+uint16_t Network_Port_APDU_Length(uint32_t object_instance)
+{
+    (void)object_instance;
+    return MAX_APDU;
+}
+
+/**
+ * For a given object instance-number, gets the network communication rate
+ * as the number of bits per second. A value of 0 indicates an unknown
+ * communication rate.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return Link_Speed for this network port, or 0 if unknown
+ */
+float Network_Port_Link_Speed(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Link_Speed = rs485_baud_rate();
+
+    return Object_List[0].Link_Speed;
+}
+
+/**
+ * @brief Set the device link speed (baud rate)
+ * @param object_instance	The object instance number of the object
+ * @param value				The new link speed value
+ * @return  true if value was set
+ */
+bool Network_Port_Link_Speed_Set(uint32_t object_instance, float value)
+{
+    bool status = false;
+    uint32_t baud = (uint32_t)value;
+
+    switch (baud) {
+        case 9600:
+        case 19200:
+        case 38400:
+        case 57600:
+        case 76800:
+        case 115200:
+            Object_List[0].Link_Speed = value;
+            Object_List[0].Changes_Pending = true;
+            status = true;
+            break;
+    }
+
+    return status;
+}
+
+/**
+ * @brief For a given object instance-number, returns the changes-pending flag
+ * @param  object_instance - object-instance number of the object
+ * @return  changes-pending property value
+ */
+bool Network_Port_Changes_Pending(uint32_t object_instance)
+{
+    bool flag = false;
+    unsigned index = 0;
+
+    index = Network_Port_Instance_To_Index(object_instance);
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        flag = Object_List[index].Changes_Pending;
+    }
+
+    return flag;
+}
+
+/**
+ * @brief For a given object instance-number, sets the changes-pending flag
+ * @param object_instance - object-instance number of the object
+ * @param flag - true=changes pending, false=no changes pending
+ * @return true if flag was set
+ */
+bool Network_Port_Changes_Pending_Set(uint32_t instance, bool flag)
+{
+    unsigned index = 0;
+
+    index = Network_Port_Instance_To_Index(instance);
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        Object_List[index].Changes_Pending = flag;
+    } else
+        return false;
+
+    return true;
+}
+
+/**
+ * @brief For a given object instance-number, gets the MS/TP Max_Master value
+ * @param  object_instance - object-instance number of the object
+ * @return MS/TP Max_Master value
+ */
+uint8_t Network_Port_MSTP_Max_Master(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Max_Master = dlmstp_max_master();
+
+    return Object_List[0].Max_Master;
+}
+
+/**
+ * For a given object instance-number, sets the MS/TP Max_Master value
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  value - MS/TP Max_Master value 0..127
+ *
+ * @return  true if values are within range and property is set.
+ */
+bool Network_Port_MSTP_Max_Master_Set(uint32_t object_instance, uint8_t value)
+{
+    bool status = false;
+
+    (void)object_instance;
+    if (value <= dlmstp_max_master_limit()) {
+        Object_List[0].Max_Master = value;
+        Object_List[0].Changes_Pending = true;
+        status = true;
+    }
+
+    return status;
+}
+
+/**
+ * For a given object instance-number, gets the MS/TP Max_Info_Frames value
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return MS/TP Max_Info_Frames value
+ */
+uint8_t Network_Port_MSTP_Max_Info_Frames(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Max_Info_Frames = dlmstp_max_info_frames();
+
+    return Object_List[0].Max_Info_Frames;
+}
+
+/**
+ * For a given object instance-number, sets the MS/TP Max_Info_Frames value
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  value - MS/TP Max_Info_Frames value 0..255
+ *
+ * @return  true if values are within range and property is set.
+ */
+bool Network_Port_MSTP_Max_Info_Frames_Set(
+    uint32_t object_instance, uint8_t value)
+{
+    bool status = false;
+
+    (void)object_instance;
+    if (value <= dlmstp_max_info_frames_limit()) {
+        Object_List[0].Max_Info_Frames = value;
+        Object_List[0].Changes_Pending = true;
+        status = true;
+    }
+
+    return status;
+}
+
+/**
+ * ReadProperty handler for this object.  For the given ReadProperty
+ * data, the application_data is loaded or the error flags are set.
+ *
+ * @param  rpdata - BACNET_READ_PROPERTY_DATA data, including
+ * requested data and space for the reply, or error response.
+ *
+ * @return number of APDU bytes in the response, or
+ * BACNET_STATUS_ERROR on error.
+ */
+int Network_Port_Read_Property(BACNET_READ_PROPERTY_DATA *rpdata)
+{
+    int apdu_len = 0;
+    BACNET_BIT_STRING bit_string;
+    BACNET_OCTET_STRING octet_string;
+    BACNET_CHARACTER_STRING char_string;
+    uint8_t *apdu = NULL;
+
+    if ((rpdata == NULL) || (rpdata->application_data == NULL) ||
+        (rpdata->application_data_len == 0)) {
+        return 0;
+    }
+    apdu = rpdata->application_data;
+    switch (rpdata->object_property) {
+        case PROP_OBJECT_IDENTIFIER:
+            apdu_len = encode_application_object_id(
+                &apdu[0], OBJECT_NETWORK_PORT, rpdata->object_instance);
+            break;
+        case PROP_OBJECT_NAME:
+            Network_Port_Object_Name(rpdata->object_instance, &char_string);
+            apdu_len =
+                encode_application_character_string(&apdu[0], &char_string);
+            break;
+        case PROP_OBJECT_TYPE:
+            apdu_len =
+                encode_application_enumerated(&apdu[0], OBJECT_NETWORK_PORT);
+            break;
+        case PROP_STATUS_FLAGS:
+            bitstring_init(&bit_string);
+            bitstring_set_bit(&bit_string, STATUS_FLAG_IN_ALARM, false);
+            if (Network_Port_Reliability(rpdata->object_instance) ==
+                RELIABILITY_NO_FAULT_DETECTED) {
+                bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, false);
+            } else {
+                bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, true);
+            }
+            bitstring_set_bit(&bit_string, STATUS_FLAG_OVERRIDDEN, false);
+            if (Network_Port_Out_Of_Service(rpdata->object_instance)) {
+                bitstring_set_bit(
+                    &bit_string, STATUS_FLAG_OUT_OF_SERVICE, true);
+            } else {
+                bitstring_set_bit(
+                    &bit_string, STATUS_FLAG_OUT_OF_SERVICE, false);
+            }
+            apdu_len = encode_application_bitstring(&apdu[0], &bit_string);
+            break;
+        case PROP_RELIABILITY:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Reliability(rpdata->object_instance));
+            break;
+        case PROP_OUT_OF_SERVICE:
+            apdu_len = encode_application_boolean(
+                &apdu[0], Network_Port_Out_Of_Service(rpdata->object_instance));
+            break;
+        case PROP_NETWORK_TYPE:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Type(rpdata->object_instance));
+            break;
+        case PROP_PROTOCOL_LEVEL:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], BACNET_PROTOCOL_LEVEL_PHYSICAL);
+            break;
+        case PROP_NETWORK_NUMBER:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_Network_Number(rpdata->object_instance));
+            break;
+        case PROP_NETWORK_NUMBER_QUALITY:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Quality(rpdata->object_instance));
+            break;
+        case PROP_MAC_ADDRESS:
+            Network_Port_MAC_Address(rpdata->object_instance, &octet_string);
+            apdu_len = encode_application_octet_string(&apdu[0], &octet_string);
+            break;
+        case PROP_MAX_APDU_LENGTH_ACCEPTED:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_APDU_Length(rpdata->object_instance));
+            break;
+        case PROP_LINK_SPEED:
+            apdu_len = encode_application_real(
+                &apdu[0], Network_Port_Link_Speed(rpdata->object_instance));
+            break;
+        case PROP_CHANGES_PENDING:
+            apdu_len = encode_application_boolean(&apdu[0],
+                Network_Port_Changes_Pending(rpdata->object_instance));
+            break;
+        case PROP_APDU_LENGTH:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_APDU_Length(rpdata->object_instance));
+            break;
+        case PROP_MAX_MASTER:
+            apdu_len = encode_application_unsigned(&apdu[0],
+                Network_Port_MSTP_Max_Master(rpdata->object_instance));
+            break;
+        case PROP_MAX_INFO_FRAMES:
+            apdu_len = encode_application_unsigned(&apdu[0],
+                Network_Port_MSTP_Max_Info_Frames(rpdata->object_instance));
+            break;
+        default:
+            rpdata->error_class = ERROR_CLASS_PROPERTY;
+            rpdata->error_code = ERROR_CODE_UNKNOWN_PROPERTY;
+            apdu_len = BACNET_STATUS_ERROR;
+            break;
+    }
+
+    return apdu_len;
+}
+
+/**
+ * WriteProperty handler for this object.  For the given WriteProperty
+ * data, the application_data is loaded or the error flags are set.
+ *
+ * @param  wp_data - BACNET_WRITE_PROPERTY_DATA data, including
+ * requested data and space for the reply, or error response.
+ *
+ * @return false if an error is loaded, true if no errors
+ */
+bool Network_Port_Write_Property(BACNET_WRITE_PROPERTY_DATA *wp_data)
+{
+    bool status = false; /* return value */
+    int len = 0;
+    BACNET_APPLICATION_DATA_VALUE value;
+
+    if (!Network_Port_Valid_Instance(wp_data->object_instance)) {
+        wp_data->error_class = ERROR_CLASS_OBJECT;
+        wp_data->error_code = ERROR_CODE_UNKNOWN_OBJECT;
+        return false;
+    }
+    /* decode the some of the request */
+    len = bacapp_decode_application_data(
+        wp_data->application_data, wp_data->application_data_len, &value);
+    if (len < 0) {
+        /* error while decoding - a value larger than we can handle */
+        wp_data->error_class = ERROR_CLASS_PROPERTY;
+        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+        return false;
+    }
+    if ((wp_data->object_property != PROP_LINK_SPEEDS) &&
+        (wp_data->object_property != PROP_IP_DNS_SERVER) &&
+        (wp_data->object_property != PROP_IPV6_DNS_SERVER) &&
+        (wp_data->object_property != PROP_EVENT_MESSAGE_TEXTS) &&
+        (wp_data->object_property != PROP_EVENT_MESSAGE_TEXTS_CONFIG) &&
+        (wp_data->object_property != PROP_TAGS) &&
+        (wp_data->array_index != BACNET_ARRAY_ALL)) {
+        /*  only array properties can have array options */
+        wp_data->error_class = ERROR_CLASS_PROPERTY;
+        wp_data->error_code = ERROR_CODE_PROPERTY_IS_NOT_AN_ARRAY;
+        return false;
+    }
+    /* FIXME: len < application_data_len: more data? */
+    switch (wp_data->object_property) {
+        case PROP_MAX_MASTER:
+            if (value.tag == BACNET_APPLICATION_TAG_UNSIGNED_INT) {
+                if (value.type.Unsigned_Int <= 255) {
+                    status = Network_Port_MSTP_Max_Master_Set(
+                        wp_data->object_instance, value.type.Unsigned_Int);
+                    if (!status) {
+                        wp_data->error_class = ERROR_CLASS_PROPERTY;
+                        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                    }
+                } else {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_MAX_INFO_FRAMES:
+            if (value.tag == BACNET_APPLICATION_TAG_UNSIGNED_INT) {
+                if (value.type.Unsigned_Int <= 255) {
+                    status = Network_Port_MSTP_Max_Info_Frames_Set(
+                        wp_data->object_instance, value.type.Unsigned_Int);
+                    if (!status) {
+                        wp_data->error_class = ERROR_CLASS_PROPERTY;
+                        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                    }
+                    status = true;
+                } else {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_LINK_SPEED:
+            if (value.tag == BACNET_APPLICATION_TAG_REAL) {
+                if (!Network_Port_Link_Speed_Set(
+                        wp_data->object_instance, value.type.Real)) {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+                status = true;
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_MAC_ADDRESS:
+            if (value.tag == BACNET_APPLICATION_TAG_OCTET_STRING) {
+                if (!Network_Port_MAC_Address_Set(wp_data->object_instance,
+                        value.type.Octet_String.value,
+                        value.type.Octet_String.length)) {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+                status = true;
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_OBJECT_IDENTIFIER:
+        case PROP_OBJECT_NAME:
+        case PROP_OBJECT_TYPE:
+        case PROP_STATUS_FLAGS:
+        case PROP_RELIABILITY:
+        case PROP_OUT_OF_SERVICE:
+        case PROP_NETWORK_TYPE:
+        case PROP_PROTOCOL_LEVEL:
+        case PROP_NETWORK_NUMBER:
+        case PROP_NETWORK_NUMBER_QUALITY:
+        case PROP_MAX_APDU_LENGTH_ACCEPTED:
+        case PROP_CHANGES_PENDING:
+        case PROP_APDU_LENGTH:
+            wp_data->error_class = ERROR_CLASS_PROPERTY;
+            wp_data->error_code = ERROR_CODE_WRITE_ACCESS_DENIED;
+            break;
+        default:
+            wp_data->error_class = ERROR_CLASS_PROPERTY;
+            wp_data->error_code = ERROR_CODE_UNKNOWN_PROPERTY;
+            break;
+    }
+
+    return status;
+}
+
+/**
+ * Initializes the Network Port object data
+ */
+void Network_Port_Init(void)
+{
+    Object_List[0].Changes_Pending = false;
+    Object_List[0].MAC_Address[0] = dlmstp_mac_address();
+    Object_List[0].Max_Master = dlmstp_max_master();
+    Object_List[0].Max_Info_Frames = dlmstp_max_info_frames();
+    Object_List[0].Link_Speed = rs485_baud_rate();
+}
diff --git a/ports/at91sam7s/rs485.c b/ports/at91sam7s/rs485.c
index b7d35063..9f37b621 100644
--- a/ports/at91sam7s/rs485.c
+++ b/ports/at91sam7s/rs485.c
@@ -118,7 +118,7 @@ void RS485_Cleanup(void)
  * ALGORITHM:   none
  * NOTES:       none
  *****************************************************************************/
-uint32_t RS485_Get_Baud_Rate(void)
+uint32_t rs485_baud_rate(void)
 {
     return RS485_Baud;
 }
@@ -129,7 +129,7 @@ uint32_t RS485_Get_Baud_Rate(void)
  * ALGORITHM:   none
  * NOTES:       none
  *****************************************************************************/
-bool RS485_Set_Baud_Rate(uint32_t baud)
+bool rs485_baud_rate_set(uint32_t baud)
 {
     bool valid = true;
 
@@ -266,7 +266,7 @@ int main(void)
     unsigned i = 0;
     uint8_t DataRegister;
 
-    RS485_Set_Baud_Rate(38400);
+    rs485_baud_rate_set(38400);
     RS485_Initialize();
     /* receive task */
     for (;;) {
diff --git a/ports/at91sam7s/rs485.h b/ports/at91sam7s/rs485.h
index ae622daa..a69b4e28 100644
--- a/ports/at91sam7s/rs485.h
+++ b/ports/at91sam7s/rs485.h
@@ -49,9 +49,9 @@ extern "C" {
 
     void RS485_Turnaround_Delay(
         void);
-    uint32_t RS485_Get_Baud_Rate(
+    uint32_t rs485_baud_rate(
         void);
-    bool RS485_Set_Baud_Rate(
+    bool rs485_baud_rate_set(
         uint32_t baud);
 
 #ifdef __cplusplus
diff --git a/ports/bdk-atxx4-mstp/Makefile b/ports/bdk-atxx4-mstp/Makefile
index debf1628..33e1f505 100644
--- a/ports/bdk-atxx4-mstp/Makefile
+++ b/ports/bdk-atxx4-mstp/Makefile
@@ -91,6 +91,7 @@ HALSRC = main.c \
 	bacnet.c \
 	bname.c \
 	device.c \
+	netport.c \
 	ai.c \
 	av.c \
 	bi.c \
@@ -218,6 +219,7 @@ BFLAGS += -DBACAPP_OBJECT_ID
 BFLAGS += -DBACAPP_UNSIGNED
 BFLAGS += -DBACAPP_ENUMERATED
 BFLAGS += -DBACAPP_CHARACTER_STRING
+BFLAGS += -DBACAPP_OCTET_STRING
 BFLAGS += -DWRITE_PROPERTY
 
 ## Compile options for C files
diff --git a/ports/bdk-atxx4-mstp/bacnet.ewp b/ports/bdk-atxx4-mstp/bacnet.ewp
index 718ac496..19c85171 100644
--- a/ports/bdk-atxx4-mstp/bacnet.ewp
+++ b/ports/bdk-atxx4-mstp/bacnet.ewp
@@ -266,6 +266,7 @@
                     <state>BACAPP_UNSIGNED</state>
                     <state>BACAPP_ENUMERATED</state>
                     <state>BACAPP_CHARACTER_STRING</state>
+                    <state>BACAPP_OCTET_STRING</state>
                     <state>WRITE_PROPERTY</state>
                 </option>
                 <option>
@@ -1331,6 +1332,7 @@
                     <state>BACAPP_UNSIGNED</state>
                     <state>BACAPP_ENUMERATED</state>
                     <state>BACAPP_CHARACTER_STRING</state>
+                    <state>BACAPP_OCTET_STRING</state>
                     <state>WRITE_PROPERTY</state>
                 </option>
                 <option>
@@ -2396,6 +2398,7 @@
                     <state>BACAPP_UNSIGNED</state>
                     <state>BACAPP_ENUMERATED</state>
                     <state>BACAPP_CHARACTER_STRING</state>
+                    <state>BACAPP_OCTET_STRING</state>
                     <state>WRITE_PROPERTY</state>
                 </option>
                 <option>
@@ -3461,6 +3464,7 @@
                     <state>BACAPP_UNSIGNED</state>
                     <state>BACAPP_ENUMERATED</state>
                     <state>BACAPP_CHARACTER_STRING</state>
+                    <state>BACAPP_OCTET_STRING</state>
                     <state>WRITE_PROPERTY</state>
                 </option>
                 <option>
diff --git a/ports/bdk-atxx4-mstp/bacnet.hzp b/ports/bdk-atxx4-mstp/bacnet.hzp
index 64dfbf9d..d5a2f033 100644
--- a/ports/bdk-atxx4-mstp/bacnet.hzp
+++ b/ports/bdk-atxx4-mstp/bacnet.hzp
@@ -1,7 +1,7 @@
 <!DOCTYPE CrossStudio_Project_File>
 <solution Name="bacnet" version="2">
   <project Name="bacnet">
-    <configuration Name="Common" Platform="AVR" Target="ATmega644P" avr_architecture="V2E" avr_debug_interface="JTAG" avr_flash_size="128K" build_use_hardware_multiplier="Yes" c_preprocessor_definitions="BACDL_MSTP;MAX_APDU=128;MAX_TSM_TRANSACTIONS=0;MAX_CHARACTER_STRING_BYTES=64;MAX_OCTET_STRING_BYTES=64;BACAPP_BOOLEAN;BACAPP_REAL;BACAPP_OBJECT_ID;BACAPP_UNSIGNED;BACAPP_ENUMERATED;BACAPP_CHARACTER_STRING;WRITE_PROPERTY" c_user_include_directories="$(ProjectDir);$(ProjectDir)/crossworks;$(ProjectDir)/../../include;$(ProjectDir)/../../src" linker_call_stack_size="1024" linker_memory_map_file="$(PackagesDir)/targets/avr/ATmega644P.xml" project_directory="" project_type="Executable"/>
+    <configuration Name="Common" Platform="AVR" Target="ATmega644P" avr_architecture="V2E" avr_debug_interface="JTAG" avr_flash_size="128K" build_use_hardware_multiplier="Yes" c_preprocessor_definitions="BACDL_MSTP;MAX_APDU=128;MAX_TSM_TRANSACTIONS=0;MAX_CHARACTER_STRING_BYTES=64;MAX_OCTET_STRING_BYTES=64;BACAPP_BOOLEAN;BACAPP_REAL;BACAPP_OBJECT_ID;BACAPP_UNSIGNED;BACAPP_ENUMERATED;BACAPP_CHARACTER_STRING;BACAPP_OCTET_STRING;WRITE_PROPERTY" c_user_include_directories="$(ProjectDir);$(ProjectDir)/crossworks;$(ProjectDir)/../../include;$(ProjectDir)/../../src" linker_call_stack_size="1024" linker_memory_map_file="$(PackagesDir)/targets/avr/ATmega644P.xml" project_directory="" project_type="Executable"/>
     <folder Name="Source Files">
       <configuration Name="Common" filter="c;h;s;asm;inc;s90"/>
       <file file_name="adc.c">
@@ -14,6 +14,7 @@
       <file file_name="bname.c"/>
       <file file_name="bo.c"/>
       <file file_name="device.c"/>
+      <file file_name="netport.c"/>
       <file file_name="dlmstp.c"/>
       <file file_name="eeprom.c"/>
       <file file_name="init.c"/>
diff --git a/ports/bdk-atxx4-mstp/device.c b/ports/bdk-atxx4-mstp/device.c
index 3de366f6..e54bc290 100644
--- a/ports/bdk-atxx4-mstp/device.c
+++ b/ports/bdk-atxx4-mstp/device.c
@@ -42,6 +42,9 @@
 #include "bacnet/proplist.h"
 /* objects */
 #include "bacnet/basic/object/device.h"
+#if (BACNET_PROTOCOL_REVISION >= 17)
+#include "bacnet/basic/object/netport.h"
+#endif
 #include "bacnet/basic/object/ai.h"
 #include "bacnet/basic/object/av.h"
 #include "bacnet/basic/object/bi.h"
@@ -64,11 +67,12 @@ static struct my_object_functions {
     read_property_function Object_Read_Property;
     write_property_function Object_Write_Property;
     rpm_property_lists_function Object_RPM_List;
-} Object_Table[] = { { OBJECT_DEVICE, NULL, /* don't init - recursive! */
-                         Device_Count, Device_Index_To_Instance,
-                         Device_Valid_Object_Instance_Number,
-                         Device_Object_Name, Device_Read_Property_Local,
-                         Device_Write_Property_Local, Device_Property_Lists },
+} Object_Table[] = {
+    { OBJECT_DEVICE, NULL, /* don't init - recursive! */
+        Device_Count, Device_Index_To_Instance,
+        Device_Valid_Object_Instance_Number,
+        Device_Object_Name, Device_Read_Property_Local,
+        Device_Write_Property_Local, Device_Property_Lists },
     { OBJECT_ANALOG_INPUT, Analog_Input_Init, Analog_Input_Count,
         Analog_Input_Index_To_Instance, Analog_Input_Valid_Instance,
         Analog_Input_Object_Name, Analog_Input_Read_Property, NULL,
@@ -85,6 +89,12 @@ static struct my_object_functions {
         Binary_Output_Index_To_Instance, Binary_Output_Valid_Instance,
         Binary_Output_Object_Name, Binary_Output_Read_Property,
         Binary_Output_Write_Property, Binary_Output_Property_Lists },
+#if (BACNET_PROTOCOL_REVISION >= 17)
+    { OBJECT_NETWORK_PORT, Network_Port_Init, Network_Port_Count,
+        Network_Port_Index_To_Instance, Network_Port_Valid_Instance,
+        Network_Port_Object_Name, Network_Port_Read_Property,
+        Network_Port_Write_Property, Network_Port_Property_Lists },
+#endif
     { MAX_BACNET_OBJECT_TYPE, NULL, NULL, NULL, NULL, NULL, NULL, NULL } };
 
 /* note: you really only need to define variables for
diff --git a/ports/bdk-atxx4-mstp/dlmstp.c b/ports/bdk-atxx4-mstp/dlmstp.c
index 4ee6479e..0be5cd11 100644
--- a/ports/bdk-atxx4-mstp/dlmstp.c
+++ b/ports/bdk-atxx4-mstp/dlmstp.c
@@ -1412,3 +1412,13 @@ void dlmstp_get_broadcast_address(BACNET_ADDRESS *dest)
 
     return;
 }
+
+uint8_t dlmstp_max_info_frames_limit(void)
+{
+    return MSTP_PDU_PACKET_COUNT;
+}
+
+uint8_t dlmstp_max_master_limit(void)
+{
+    return 127;
+}
diff --git a/ports/bdk-atxx4-mstp/netport.c b/ports/bdk-atxx4-mstp/netport.c
new file mode 100644
index 00000000..3a2899a6
--- /dev/null
+++ b/ports/bdk-atxx4-mstp/netport.c
@@ -0,0 +1,748 @@
+/**
+ * @file
+ * @author Steve Karg
+ * @date 2016
+ * @brief Network port objects, customize for your use
+ *
+ * @section DESCRIPTION
+ *
+ * The Network Port object provides access to the configuration
+ * and properties of network ports of a device.
+ *
+ * @section LICENSE
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include "bacnet/config.h"
+#include "bacnet/basic/binding/address.h"
+#include "bacnet/bacdef.h"
+#include "bacnet/bacapp.h"
+#include "bacnet/bacdcode.h"
+#include "bacnet/npdu.h"
+#include "bacnet/apdu.h"
+#include "bacnet/basic/object/device.h"
+/* MS/TP specific */
+#include "bacnet/datalink/dlmstp.h"
+#include "rs485.h"
+//#include "nvdata.h"
+/* me */
+#include "bacnet/basic/object/netport.h"
+
+/* our local object data */
+struct object_data {
+    bool Changes_Pending : 1;
+    uint8_t MAC_Address[1];
+    uint8_t Max_Master;
+    uint8_t Max_Info_Frames;
+    float Link_Speed;
+};
+
+/* this object example only supports 1 instance */
+#define BACNET_NETWORK_PORTS_MAX 1
+struct object_data Object_List[BACNET_NETWORK_PORTS_MAX];
+/* instance number - can be overridden */
+#ifndef BACNET_NETWORK_PORT_INSTANCE
+#define BACNET_NETWORK_PORT_INSTANCE 1
+#endif
+
+/* These three arrays are used by the ReadPropertyMultiple handler */
+static const int Network_Port_Properties_Required[] = { PROP_OBJECT_IDENTIFIER,
+    PROP_OBJECT_NAME, PROP_OBJECT_TYPE, PROP_STATUS_FLAGS, PROP_RELIABILITY,
+    PROP_OUT_OF_SERVICE, PROP_NETWORK_TYPE, PROP_PROTOCOL_LEVEL,
+    PROP_NETWORK_NUMBER, PROP_NETWORK_NUMBER_QUALITY, PROP_CHANGES_PENDING,
+    PROP_APDU_LENGTH, PROP_LINK_SPEED, -1 };
+
+static const int Network_Port_Properties_Optional[] = { PROP_MAC_ADDRESS,
+    PROP_MAX_MASTER, PROP_MAX_INFO_FRAMES, -1 };
+
+static const int Network_Port_Properties_Proprietary[] = { -1 };
+
+/**
+ * Returns the list of required, optional, and proprietary properties.
+ * Used by ReadPropertyMultiple service.
+ *
+ * @param object_instance - object-instance number of the object
+ * @param pRequired - pointer to list of int terminated by -1, of
+ * BACnet required properties for this object.
+ * @param pOptional - pointer to list of int terminated by -1, of
+ * BACnet optkional properties for this object.
+ * @param pProprietary - pointer to list of int terminated by -1, of
+ * BACnet proprietary properties for this object.
+ */
+void Network_Port_Property_List(uint32_t object_instance,
+    const int **pRequired,
+    const int **pOptional,
+    const int **pProprietary)
+{
+    (void)object_instance;
+    if (pRequired) {
+        *pRequired = Network_Port_Properties_Required;
+    }
+    if (pOptional) {
+        *pOptional = Network_Port_Properties_Optional;
+    }
+    if (pProprietary) {
+        *pProprietary = Network_Port_Properties_Proprietary;
+    }
+
+    return;
+}
+
+/**
+ * Returns the list of required, optional, and proprietary properties.
+ * Used by ReadPropertyMultiple service.
+ *
+ * @param pRequired - pointer to list of int terminated by -1, of
+ * BACnet required properties for this object.
+ * @param pOptional - pointer to list of int terminated by -1, of
+ * BACnet optkional properties for this object.
+ * @param pProprietary - pointer to list of int terminated by -1, of
+ * BACnet proprietary properties for this object.
+ */
+void Network_Port_Property_Lists(
+    const int **pRequired, const int **pOptional, const int **pProprietary)
+{
+    Network_Port_Property_List(
+        BACNET_NETWORK_PORT_INSTANCE, pRequired, pOptional, pProprietary);
+}
+
+/**
+ * For a given object instance-number, loads the object-name into
+ * a characterstring. Note that the object name must be unique
+ * within this device.
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  object_name - holds the object-name retrieved
+ *
+ * @return  true if object-name was retrieved
+ */
+bool Network_Port_Object_Name(
+    uint32_t object_instance, BACNET_CHARACTER_STRING *object_name)
+{
+    bool status = false;
+
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        status = characterstring_init_ansi(object_name, "NP-1");
+    }
+
+    return status;
+}
+
+/**
+ * Determines if a given Network Port instance is valid
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  true if the instance is valid, and false if not
+ */
+bool Network_Port_Valid_Instance(uint32_t object_instance)
+{
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        return true;
+    }
+
+    return false;
+}
+
+/**
+ * Determines the number of Network Port objects
+ *
+ * @return  Number of Network Port objects
+ */
+unsigned Network_Port_Count(void)
+{
+    return BACNET_NETWORK_PORTS_MAX;
+}
+
+/**
+ * Determines the object instance-number for a given 0..N index
+ * of Network Port objects where N is Network_Port_Count().
+ *
+ * @param index - 0..BACNET_NETWORK_PORTS_MAX value
+ *
+ * @return object instance-number for the given index, or BACNET_MAX_INSTANCE
+ * for an invalid index.
+ */
+uint32_t Network_Port_Index_To_Instance(unsigned index)
+{
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        return BACNET_NETWORK_PORT_INSTANCE;
+    }
+
+    return BACNET_MAX_INSTANCE;
+}
+
+/**
+ * For a given object instance-number, determines a 0..N index
+ * of Network Port objects where N is Network_Port_Count().
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  index for the given instance-number, or BACNET_NETWORK_PORTS_MAX
+ * if not valid.
+ */
+unsigned Network_Port_Instance_To_Index(uint32_t object_instance)
+{
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        return 0;
+    }
+
+    return BACNET_NETWORK_PORTS_MAX;
+}
+
+/**
+ * For a given object instance-number, returns the out-of-service
+ * property value
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  out-of-service property value
+ */
+bool Network_Port_Out_Of_Service(uint32_t object_instance)
+{
+    (void)object_instance;
+    return false;
+}
+
+/**
+ * For a given object instance-number, gets the reliability.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return reliability value
+ */
+BACNET_RELIABILITY Network_Port_Reliability(uint32_t object_instance)
+{
+    (void)object_instance;
+    return RELIABILITY_NO_FAULT_DETECTED;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Type.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return BACnet network type value
+ */
+uint8_t Network_Port_Type(uint32_t object_instance)
+{
+    (void)object_instance;
+    return PORT_TYPE_MSTP;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Number.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return BACnet network type value
+ */
+uint16_t Network_Port_Network_Number(uint32_t object_instance)
+{
+    (void)object_instance;
+    /* A Network_Number of 0 indicates that the Network_Number
+       is not known or cannot be determined. */
+    return 0;
+}
+
+/**
+ * For a given object instance-number, gets the quality property
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return quality property value
+ */
+BACNET_PORT_QUALITY Network_Port_Quality(uint32_t object_instance)
+{
+    (void)object_instance;
+    return PORT_QUALITY_CONFIGURED;
+}
+
+/**
+ * For a given object instance-number, loads the mac-address into
+ * an octet string.
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  mac_address - holds the mac-address retrieved
+ *
+ * @return  true if mac-address was retrieved
+ */
+bool Network_Port_MAC_Address(
+    uint32_t object_instance, BACNET_OCTET_STRING *mac_address)
+{
+    (void)object_instance;
+    Object_List[0].MAC_Address[0] = dlmstp_mac_address();
+
+    return octetstring_init(mac_address, Object_List[0].MAC_Address, 1);
+}
+
+/**
+ * @brief For a given object instance-number, set the mac-address and length
+ * @param  object_instance - object-instance number of the object
+ * @param  mac_src - holds the MAC address to be written
+ * @param  mac_len - number of bytes in the MAC address
+ * @return  true if object-name was set
+ */
+bool Network_Port_MAC_Address_Set(
+    uint32_t object_instance, uint8_t *mac_src, uint8_t mac_len)
+{
+    if (mac_len == 1) {
+        Object_List[0].MAC_Address[0] = mac_src[0];
+        Object_List[0].Changes_Pending = true;
+        return true;
+    }
+
+    return false;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Number.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return APDU length for this network port
+ */
+uint16_t Network_Port_APDU_Length(uint32_t object_instance)
+{
+    (void)object_instance;
+    return MAX_APDU;
+}
+
+/**
+ * For a given object instance-number, gets the network communication rate
+ * as the number of bits per second. A value of 0 indicates an unknown
+ * communication rate.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return Link_Speed for this network port, or 0 if unknown
+ */
+float Network_Port_Link_Speed(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Link_Speed = rs485_baud_rate();
+
+    return Object_List[0].Link_Speed;
+}
+
+/**
+ * @brief Set the device link speed (baud rate)
+ * @param object_instance	The object instance number of the object
+ * @param value				The new link speed value
+ * @return  true if value was set
+ */
+bool Network_Port_Link_Speed_Set(uint32_t object_instance, float value)
+{
+    bool status = false;
+    uint32_t baud = (uint32_t)value;
+
+    switch (baud) {
+        case 9600:
+        case 19200:
+        case 38400:
+        case 57600:
+        case 76800:
+        case 115200:
+            Object_List[0].Link_Speed = value;
+            Object_List[0].Changes_Pending = true;
+            status = true;
+            break;
+    }
+
+    return status;
+}
+
+/**
+ * @brief For a given object instance-number, returns the changes-pending flag
+ * @param  object_instance - object-instance number of the object
+ * @return  changes-pending property value
+ */
+bool Network_Port_Changes_Pending(uint32_t object_instance)
+{
+    bool flag = false;
+    unsigned index = 0;
+
+    index = Network_Port_Instance_To_Index(object_instance);
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        flag = Object_List[index].Changes_Pending;
+    }
+
+    return flag;
+}
+
+/**
+ * @brief For a given object instance-number, sets the changes-pending flag
+ * @param object_instance - object-instance number of the object
+ * @param flag - true=changes pending, false=no changes pending
+ * @return true if flag was set
+ */
+bool Network_Port_Changes_Pending_Set(uint32_t instance, bool flag)
+{
+    unsigned index = 0;
+
+    index = Network_Port_Instance_To_Index(instance);
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        Object_List[index].Changes_Pending = flag;
+    } else
+        return false;
+
+    return true;
+}
+
+/**
+ * @brief For a given object instance-number, gets the MS/TP Max_Master value
+ * @param  object_instance - object-instance number of the object
+ * @return MS/TP Max_Master value
+ */
+uint8_t Network_Port_MSTP_Max_Master(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Max_Master = dlmstp_max_master();
+
+    return Object_List[0].Max_Master;
+}
+
+/**
+ * For a given object instance-number, sets the MS/TP Max_Master value
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  value - MS/TP Max_Master value 0..127
+ *
+ * @return  true if values are within range and property is set.
+ */
+bool Network_Port_MSTP_Max_Master_Set(uint32_t object_instance, uint8_t value)
+{
+    bool status = false;
+
+    (void)object_instance;
+    if (value <= dlmstp_max_master_limit()) {
+        Object_List[0].Max_Master = value;
+        Object_List[0].Changes_Pending = true;
+        status = true;
+    }
+
+    return status;
+}
+
+/**
+ * For a given object instance-number, gets the MS/TP Max_Info_Frames value
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return MS/TP Max_Info_Frames value
+ */
+uint8_t Network_Port_MSTP_Max_Info_Frames(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Max_Info_Frames = dlmstp_max_info_frames();
+
+    return Object_List[0].Max_Info_Frames;
+}
+
+/**
+ * For a given object instance-number, sets the MS/TP Max_Info_Frames value
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  value - MS/TP Max_Info_Frames value 0..255
+ *
+ * @return  true if values are within range and property is set.
+ */
+bool Network_Port_MSTP_Max_Info_Frames_Set(
+    uint32_t object_instance, uint8_t value)
+{
+    bool status = false;
+
+    (void)object_instance;
+    if (value <= dlmstp_max_info_frames_limit()) {
+        Object_List[0].Max_Info_Frames = value;
+        Object_List[0].Changes_Pending = true;
+        status = true;
+    }
+
+    return status;
+}
+
+/**
+ * ReadProperty handler for this object.  For the given ReadProperty
+ * data, the application_data is loaded or the error flags are set.
+ *
+ * @param  rpdata - BACNET_READ_PROPERTY_DATA data, including
+ * requested data and space for the reply, or error response.
+ *
+ * @return number of APDU bytes in the response, or
+ * BACNET_STATUS_ERROR on error.
+ */
+int Network_Port_Read_Property(BACNET_READ_PROPERTY_DATA *rpdata)
+{
+    int apdu_len = 0;
+    BACNET_BIT_STRING bit_string;
+    BACNET_OCTET_STRING octet_string;
+    BACNET_CHARACTER_STRING char_string;
+    uint8_t *apdu = NULL;
+
+    if ((rpdata == NULL) || (rpdata->application_data == NULL) ||
+        (rpdata->application_data_len == 0)) {
+        return 0;
+    }
+    apdu = rpdata->application_data;
+    switch (rpdata->object_property) {
+        case PROP_OBJECT_IDENTIFIER:
+            apdu_len = encode_application_object_id(
+                &apdu[0], OBJECT_NETWORK_PORT, rpdata->object_instance);
+            break;
+        case PROP_OBJECT_NAME:
+            Network_Port_Object_Name(rpdata->object_instance, &char_string);
+            apdu_len =
+                encode_application_character_string(&apdu[0], &char_string);
+            break;
+        case PROP_OBJECT_TYPE:
+            apdu_len =
+                encode_application_enumerated(&apdu[0], OBJECT_NETWORK_PORT);
+            break;
+        case PROP_STATUS_FLAGS:
+            bitstring_init(&bit_string);
+            bitstring_set_bit(&bit_string, STATUS_FLAG_IN_ALARM, false);
+            if (Network_Port_Reliability(rpdata->object_instance) ==
+                RELIABILITY_NO_FAULT_DETECTED) {
+                bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, false);
+            } else {
+                bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, true);
+            }
+            bitstring_set_bit(&bit_string, STATUS_FLAG_OVERRIDDEN, false);
+            if (Network_Port_Out_Of_Service(rpdata->object_instance)) {
+                bitstring_set_bit(
+                    &bit_string, STATUS_FLAG_OUT_OF_SERVICE, true);
+            } else {
+                bitstring_set_bit(
+                    &bit_string, STATUS_FLAG_OUT_OF_SERVICE, false);
+            }
+            apdu_len = encode_application_bitstring(&apdu[0], &bit_string);
+            break;
+        case PROP_RELIABILITY:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Reliability(rpdata->object_instance));
+            break;
+        case PROP_OUT_OF_SERVICE:
+            apdu_len = encode_application_boolean(
+                &apdu[0], Network_Port_Out_Of_Service(rpdata->object_instance));
+            break;
+        case PROP_NETWORK_TYPE:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Type(rpdata->object_instance));
+            break;
+        case PROP_PROTOCOL_LEVEL:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], BACNET_PROTOCOL_LEVEL_PHYSICAL);
+            break;
+        case PROP_NETWORK_NUMBER:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_Network_Number(rpdata->object_instance));
+            break;
+        case PROP_NETWORK_NUMBER_QUALITY:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Quality(rpdata->object_instance));
+            break;
+        case PROP_MAC_ADDRESS:
+            Network_Port_MAC_Address(rpdata->object_instance, &octet_string);
+            apdu_len = encode_application_octet_string(&apdu[0], &octet_string);
+            break;
+        case PROP_MAX_APDU_LENGTH_ACCEPTED:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_APDU_Length(rpdata->object_instance));
+            break;
+        case PROP_LINK_SPEED:
+            apdu_len = encode_application_real(
+                &apdu[0], Network_Port_Link_Speed(rpdata->object_instance));
+            break;
+        case PROP_CHANGES_PENDING:
+            apdu_len = encode_application_boolean(&apdu[0],
+                Network_Port_Changes_Pending(rpdata->object_instance));
+            break;
+        case PROP_APDU_LENGTH:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_APDU_Length(rpdata->object_instance));
+            break;
+        case PROP_MAX_MASTER:
+            apdu_len = encode_application_unsigned(&apdu[0],
+                Network_Port_MSTP_Max_Master(rpdata->object_instance));
+            break;
+        case PROP_MAX_INFO_FRAMES:
+            apdu_len = encode_application_unsigned(&apdu[0],
+                Network_Port_MSTP_Max_Info_Frames(rpdata->object_instance));
+            break;
+        default:
+            rpdata->error_class = ERROR_CLASS_PROPERTY;
+            rpdata->error_code = ERROR_CODE_UNKNOWN_PROPERTY;
+            apdu_len = BACNET_STATUS_ERROR;
+            break;
+    }
+
+    return apdu_len;
+}
+
+/**
+ * WriteProperty handler for this object.  For the given WriteProperty
+ * data, the application_data is loaded or the error flags are set.
+ *
+ * @param  wp_data - BACNET_WRITE_PROPERTY_DATA data, including
+ * requested data and space for the reply, or error response.
+ *
+ * @return false if an error is loaded, true if no errors
+ */
+bool Network_Port_Write_Property(BACNET_WRITE_PROPERTY_DATA *wp_data)
+{
+    bool status = false; /* return value */
+    int len = 0;
+    BACNET_APPLICATION_DATA_VALUE value;
+
+    if (!Network_Port_Valid_Instance(wp_data->object_instance)) {
+        wp_data->error_class = ERROR_CLASS_OBJECT;
+        wp_data->error_code = ERROR_CODE_UNKNOWN_OBJECT;
+        return false;
+    }
+    /* decode the some of the request */
+    len = bacapp_decode_application_data(
+        wp_data->application_data, wp_data->application_data_len, &value);
+    if (len < 0) {
+        /* error while decoding - a value larger than we can handle */
+        wp_data->error_class = ERROR_CLASS_PROPERTY;
+        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+        return false;
+    }
+    if ((wp_data->object_property != PROP_LINK_SPEEDS) &&
+        (wp_data->object_property != PROP_IP_DNS_SERVER) &&
+        (wp_data->object_property != PROP_IPV6_DNS_SERVER) &&
+        (wp_data->object_property != PROP_EVENT_MESSAGE_TEXTS) &&
+        (wp_data->object_property != PROP_EVENT_MESSAGE_TEXTS_CONFIG) &&
+        (wp_data->object_property != PROP_TAGS) &&
+        (wp_data->array_index != BACNET_ARRAY_ALL)) {
+        /*  only array properties can have array options */
+        wp_data->error_class = ERROR_CLASS_PROPERTY;
+        wp_data->error_code = ERROR_CODE_PROPERTY_IS_NOT_AN_ARRAY;
+        return false;
+    }
+    /* FIXME: len < application_data_len: more data? */
+    switch (wp_data->object_property) {
+        case PROP_MAX_MASTER:
+            if (value.tag == BACNET_APPLICATION_TAG_UNSIGNED_INT) {
+                if (value.type.Unsigned_Int <= 255) {
+                    status = Network_Port_MSTP_Max_Master_Set(
+                        wp_data->object_instance, value.type.Unsigned_Int);
+                    if (!status) {
+                        wp_data->error_class = ERROR_CLASS_PROPERTY;
+                        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                    }
+                } else {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_MAX_INFO_FRAMES:
+            if (value.tag == BACNET_APPLICATION_TAG_UNSIGNED_INT) {
+                if (value.type.Unsigned_Int <= 255) {
+                    status = Network_Port_MSTP_Max_Info_Frames_Set(
+                        wp_data->object_instance, value.type.Unsigned_Int);
+                    if (!status) {
+                        wp_data->error_class = ERROR_CLASS_PROPERTY;
+                        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                    }
+                    status = true;
+                } else {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_LINK_SPEED:
+            if (value.tag == BACNET_APPLICATION_TAG_REAL) {
+                if (!Network_Port_Link_Speed_Set(
+                        wp_data->object_instance, value.type.Real)) {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+                status = true;
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_MAC_ADDRESS:
+            if (value.tag == BACNET_APPLICATION_TAG_OCTET_STRING) {
+                if (!Network_Port_MAC_Address_Set(wp_data->object_instance,
+                        value.type.Octet_String.value,
+                        value.type.Octet_String.length)) {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+                status = true;
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_OBJECT_IDENTIFIER:
+        case PROP_OBJECT_NAME:
+        case PROP_OBJECT_TYPE:
+        case PROP_STATUS_FLAGS:
+        case PROP_RELIABILITY:
+        case PROP_OUT_OF_SERVICE:
+        case PROP_NETWORK_TYPE:
+        case PROP_PROTOCOL_LEVEL:
+        case PROP_NETWORK_NUMBER:
+        case PROP_NETWORK_NUMBER_QUALITY:
+        case PROP_MAX_APDU_LENGTH_ACCEPTED:
+        case PROP_CHANGES_PENDING:
+        case PROP_APDU_LENGTH:
+            wp_data->error_class = ERROR_CLASS_PROPERTY;
+            wp_data->error_code = ERROR_CODE_WRITE_ACCESS_DENIED;
+            break;
+        default:
+            wp_data->error_class = ERROR_CLASS_PROPERTY;
+            wp_data->error_code = ERROR_CODE_UNKNOWN_PROPERTY;
+            break;
+    }
+
+    return status;
+}
+
+/**
+ * Initializes the Network Port object data
+ */
+void Network_Port_Init(void)
+{
+    Object_List[0].Changes_Pending = false;
+    Object_List[0].MAC_Address[0] = dlmstp_mac_address();
+    Object_List[0].Max_Master = dlmstp_max_master();
+    Object_List[0].Max_Info_Frames = dlmstp_max_info_frames();
+    Object_List[0].Link_Speed = rs485_baud_rate();
+}
diff --git a/ports/stm32f10x/Makefile b/ports/stm32f10x/Makefile
index d90aadf4..c4d12391 100644
--- a/ports/stm32f10x/Makefile
+++ b/ports/stm32f10x/Makefile
@@ -25,6 +25,7 @@ PLATFORM_SRC = \
 	$(PLATFORM_DIR)/bo.c \
 	$(PLATFORM_DIR)/device.c \
 	$(PLATFORM_DIR)/dlmstp.c \
+	$(PLATFORM_DIR)/netport.c \
 	$(PLATFORM_DIR)/led.c \
 	$(PLATFORM_DIR)/rs485.c \
 	$(PLATFORM_DIR)/stm32f10x_it.c \
diff --git a/ports/stm32f10x/bacnet.ewp b/ports/stm32f10x/bacnet.ewp
index 5ddc79cd..247f54df 100644
--- a/ports/stm32f10x/bacnet.ewp
+++ b/ports/stm32f10x/bacnet.ewp
@@ -1275,6 +1275,9 @@
     <file>
         <name>$PROJ_DIR$\mstimer-init.c</name>
     </file>
+    <file>
+        <name>$PROJ_DIR$\netport.c</name>
+    </file>
     <file>
         <name>$PROJ_DIR$\rs485.c</name>
     </file>
diff --git a/ports/stm32f10x/device.c b/ports/stm32f10x/device.c
index 8afd246a..266222ed 100644
--- a/ports/stm32f10x/device.c
+++ b/ports/stm32f10x/device.c
@@ -41,6 +41,9 @@
 /* objects */
 #include "bacnet/basic/object/device.h"
 #include "bacnet/basic/object/bo.h"
+#if (BACNET_PROTOCOL_REVISION >= 17)
+#include "bacnet/basic/object/netport.h"
+#endif
 
 /* forward prototype */
 int Device_Read_Property_Local(BACNET_READ_PROPERTY_DATA *rpdata);
@@ -56,15 +59,22 @@ static struct my_object_functions {
     read_property_function Object_Read_Property;
     write_property_function Object_Write_Property;
     rpm_property_lists_function Object_RPM_List;
-} Object_Table[] = { { OBJECT_DEVICE, NULL, /* don't init - recursive! */
-                         Device_Count, Device_Index_To_Instance,
-                         Device_Valid_Object_Instance_Number,
-                         Device_Object_Name, Device_Read_Property_Local,
-                         Device_Write_Property_Local, Device_Property_Lists },
+} Object_Table[] = {
+    { OBJECT_DEVICE, NULL, /* don't init - recursive! */
+        Device_Count, Device_Index_To_Instance,
+        Device_Valid_Object_Instance_Number,
+        Device_Object_Name, Device_Read_Property_Local,
+        Device_Write_Property_Local, Device_Property_Lists },
     { OBJECT_BINARY_OUTPUT, Binary_Output_Init, Binary_Output_Count,
         Binary_Output_Index_To_Instance, Binary_Output_Valid_Instance,
         Binary_Output_Object_Name, Binary_Output_Read_Property,
         Binary_Output_Write_Property, Binary_Output_Property_Lists },
+#if (BACNET_PROTOCOL_REVISION >= 17)
+    { OBJECT_NETWORK_PORT, Network_Port_Init, Network_Port_Count,
+        Network_Port_Index_To_Instance, Network_Port_Valid_Instance,
+        Network_Port_Object_Name, Network_Port_Read_Property,
+        Network_Port_Write_Property, Network_Port_Property_Lists },
+#endif
     { MAX_BACNET_OBJECT_TYPE, NULL, NULL, NULL, NULL, NULL, NULL, NULL } };
 
 /* note: you really only need to define variables for
diff --git a/ports/stm32f10x/dlmstp.c b/ports/stm32f10x/dlmstp.c
index f898e946..5ebc1880 100644
--- a/ports/stm32f10x/dlmstp.c
+++ b/ports/stm32f10x/dlmstp.c
@@ -1641,3 +1641,13 @@ bool dlmstp_sole_master(void)
 
     return false;
 }
+
+uint8_t dlmstp_max_info_frames_limit(void)
+{
+    return MSTP_PDU_PACKET_COUNT;
+}
+
+uint8_t dlmstp_max_master_limit(void)
+{
+    return 127;
+}
diff --git a/ports/stm32f10x/netport.c b/ports/stm32f10x/netport.c
new file mode 100644
index 00000000..3a2899a6
--- /dev/null
+++ b/ports/stm32f10x/netport.c
@@ -0,0 +1,748 @@
+/**
+ * @file
+ * @author Steve Karg
+ * @date 2016
+ * @brief Network port objects, customize for your use
+ *
+ * @section DESCRIPTION
+ *
+ * The Network Port object provides access to the configuration
+ * and properties of network ports of a device.
+ *
+ * @section LICENSE
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include "bacnet/config.h"
+#include "bacnet/basic/binding/address.h"
+#include "bacnet/bacdef.h"
+#include "bacnet/bacapp.h"
+#include "bacnet/bacdcode.h"
+#include "bacnet/npdu.h"
+#include "bacnet/apdu.h"
+#include "bacnet/basic/object/device.h"
+/* MS/TP specific */
+#include "bacnet/datalink/dlmstp.h"
+#include "rs485.h"
+//#include "nvdata.h"
+/* me */
+#include "bacnet/basic/object/netport.h"
+
+/* our local object data */
+struct object_data {
+    bool Changes_Pending : 1;
+    uint8_t MAC_Address[1];
+    uint8_t Max_Master;
+    uint8_t Max_Info_Frames;
+    float Link_Speed;
+};
+
+/* this object example only supports 1 instance */
+#define BACNET_NETWORK_PORTS_MAX 1
+struct object_data Object_List[BACNET_NETWORK_PORTS_MAX];
+/* instance number - can be overridden */
+#ifndef BACNET_NETWORK_PORT_INSTANCE
+#define BACNET_NETWORK_PORT_INSTANCE 1
+#endif
+
+/* These three arrays are used by the ReadPropertyMultiple handler */
+static const int Network_Port_Properties_Required[] = { PROP_OBJECT_IDENTIFIER,
+    PROP_OBJECT_NAME, PROP_OBJECT_TYPE, PROP_STATUS_FLAGS, PROP_RELIABILITY,
+    PROP_OUT_OF_SERVICE, PROP_NETWORK_TYPE, PROP_PROTOCOL_LEVEL,
+    PROP_NETWORK_NUMBER, PROP_NETWORK_NUMBER_QUALITY, PROP_CHANGES_PENDING,
+    PROP_APDU_LENGTH, PROP_LINK_SPEED, -1 };
+
+static const int Network_Port_Properties_Optional[] = { PROP_MAC_ADDRESS,
+    PROP_MAX_MASTER, PROP_MAX_INFO_FRAMES, -1 };
+
+static const int Network_Port_Properties_Proprietary[] = { -1 };
+
+/**
+ * Returns the list of required, optional, and proprietary properties.
+ * Used by ReadPropertyMultiple service.
+ *
+ * @param object_instance - object-instance number of the object
+ * @param pRequired - pointer to list of int terminated by -1, of
+ * BACnet required properties for this object.
+ * @param pOptional - pointer to list of int terminated by -1, of
+ * BACnet optkional properties for this object.
+ * @param pProprietary - pointer to list of int terminated by -1, of
+ * BACnet proprietary properties for this object.
+ */
+void Network_Port_Property_List(uint32_t object_instance,
+    const int **pRequired,
+    const int **pOptional,
+    const int **pProprietary)
+{
+    (void)object_instance;
+    if (pRequired) {
+        *pRequired = Network_Port_Properties_Required;
+    }
+    if (pOptional) {
+        *pOptional = Network_Port_Properties_Optional;
+    }
+    if (pProprietary) {
+        *pProprietary = Network_Port_Properties_Proprietary;
+    }
+
+    return;
+}
+
+/**
+ * Returns the list of required, optional, and proprietary properties.
+ * Used by ReadPropertyMultiple service.
+ *
+ * @param pRequired - pointer to list of int terminated by -1, of
+ * BACnet required properties for this object.
+ * @param pOptional - pointer to list of int terminated by -1, of
+ * BACnet optkional properties for this object.
+ * @param pProprietary - pointer to list of int terminated by -1, of
+ * BACnet proprietary properties for this object.
+ */
+void Network_Port_Property_Lists(
+    const int **pRequired, const int **pOptional, const int **pProprietary)
+{
+    Network_Port_Property_List(
+        BACNET_NETWORK_PORT_INSTANCE, pRequired, pOptional, pProprietary);
+}
+
+/**
+ * For a given object instance-number, loads the object-name into
+ * a characterstring. Note that the object name must be unique
+ * within this device.
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  object_name - holds the object-name retrieved
+ *
+ * @return  true if object-name was retrieved
+ */
+bool Network_Port_Object_Name(
+    uint32_t object_instance, BACNET_CHARACTER_STRING *object_name)
+{
+    bool status = false;
+
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        status = characterstring_init_ansi(object_name, "NP-1");
+    }
+
+    return status;
+}
+
+/**
+ * Determines if a given Network Port instance is valid
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  true if the instance is valid, and false if not
+ */
+bool Network_Port_Valid_Instance(uint32_t object_instance)
+{
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        return true;
+    }
+
+    return false;
+}
+
+/**
+ * Determines the number of Network Port objects
+ *
+ * @return  Number of Network Port objects
+ */
+unsigned Network_Port_Count(void)
+{
+    return BACNET_NETWORK_PORTS_MAX;
+}
+
+/**
+ * Determines the object instance-number for a given 0..N index
+ * of Network Port objects where N is Network_Port_Count().
+ *
+ * @param index - 0..BACNET_NETWORK_PORTS_MAX value
+ *
+ * @return object instance-number for the given index, or BACNET_MAX_INSTANCE
+ * for an invalid index.
+ */
+uint32_t Network_Port_Index_To_Instance(unsigned index)
+{
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        return BACNET_NETWORK_PORT_INSTANCE;
+    }
+
+    return BACNET_MAX_INSTANCE;
+}
+
+/**
+ * For a given object instance-number, determines a 0..N index
+ * of Network Port objects where N is Network_Port_Count().
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  index for the given instance-number, or BACNET_NETWORK_PORTS_MAX
+ * if not valid.
+ */
+unsigned Network_Port_Instance_To_Index(uint32_t object_instance)
+{
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        return 0;
+    }
+
+    return BACNET_NETWORK_PORTS_MAX;
+}
+
+/**
+ * For a given object instance-number, returns the out-of-service
+ * property value
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  out-of-service property value
+ */
+bool Network_Port_Out_Of_Service(uint32_t object_instance)
+{
+    (void)object_instance;
+    return false;
+}
+
+/**
+ * For a given object instance-number, gets the reliability.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return reliability value
+ */
+BACNET_RELIABILITY Network_Port_Reliability(uint32_t object_instance)
+{
+    (void)object_instance;
+    return RELIABILITY_NO_FAULT_DETECTED;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Type.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return BACnet network type value
+ */
+uint8_t Network_Port_Type(uint32_t object_instance)
+{
+    (void)object_instance;
+    return PORT_TYPE_MSTP;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Number.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return BACnet network type value
+ */
+uint16_t Network_Port_Network_Number(uint32_t object_instance)
+{
+    (void)object_instance;
+    /* A Network_Number of 0 indicates that the Network_Number
+       is not known or cannot be determined. */
+    return 0;
+}
+
+/**
+ * For a given object instance-number, gets the quality property
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return quality property value
+ */
+BACNET_PORT_QUALITY Network_Port_Quality(uint32_t object_instance)
+{
+    (void)object_instance;
+    return PORT_QUALITY_CONFIGURED;
+}
+
+/**
+ * For a given object instance-number, loads the mac-address into
+ * an octet string.
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  mac_address - holds the mac-address retrieved
+ *
+ * @return  true if mac-address was retrieved
+ */
+bool Network_Port_MAC_Address(
+    uint32_t object_instance, BACNET_OCTET_STRING *mac_address)
+{
+    (void)object_instance;
+    Object_List[0].MAC_Address[0] = dlmstp_mac_address();
+
+    return octetstring_init(mac_address, Object_List[0].MAC_Address, 1);
+}
+
+/**
+ * @brief For a given object instance-number, set the mac-address and length
+ * @param  object_instance - object-instance number of the object
+ * @param  mac_src - holds the MAC address to be written
+ * @param  mac_len - number of bytes in the MAC address
+ * @return  true if object-name was set
+ */
+bool Network_Port_MAC_Address_Set(
+    uint32_t object_instance, uint8_t *mac_src, uint8_t mac_len)
+{
+    if (mac_len == 1) {
+        Object_List[0].MAC_Address[0] = mac_src[0];
+        Object_List[0].Changes_Pending = true;
+        return true;
+    }
+
+    return false;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Number.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return APDU length for this network port
+ */
+uint16_t Network_Port_APDU_Length(uint32_t object_instance)
+{
+    (void)object_instance;
+    return MAX_APDU;
+}
+
+/**
+ * For a given object instance-number, gets the network communication rate
+ * as the number of bits per second. A value of 0 indicates an unknown
+ * communication rate.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return Link_Speed for this network port, or 0 if unknown
+ */
+float Network_Port_Link_Speed(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Link_Speed = rs485_baud_rate();
+
+    return Object_List[0].Link_Speed;
+}
+
+/**
+ * @brief Set the device link speed (baud rate)
+ * @param object_instance	The object instance number of the object
+ * @param value				The new link speed value
+ * @return  true if value was set
+ */
+bool Network_Port_Link_Speed_Set(uint32_t object_instance, float value)
+{
+    bool status = false;
+    uint32_t baud = (uint32_t)value;
+
+    switch (baud) {
+        case 9600:
+        case 19200:
+        case 38400:
+        case 57600:
+        case 76800:
+        case 115200:
+            Object_List[0].Link_Speed = value;
+            Object_List[0].Changes_Pending = true;
+            status = true;
+            break;
+    }
+
+    return status;
+}
+
+/**
+ * @brief For a given object instance-number, returns the changes-pending flag
+ * @param  object_instance - object-instance number of the object
+ * @return  changes-pending property value
+ */
+bool Network_Port_Changes_Pending(uint32_t object_instance)
+{
+    bool flag = false;
+    unsigned index = 0;
+
+    index = Network_Port_Instance_To_Index(object_instance);
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        flag = Object_List[index].Changes_Pending;
+    }
+
+    return flag;
+}
+
+/**
+ * @brief For a given object instance-number, sets the changes-pending flag
+ * @param object_instance - object-instance number of the object
+ * @param flag - true=changes pending, false=no changes pending
+ * @return true if flag was set
+ */
+bool Network_Port_Changes_Pending_Set(uint32_t instance, bool flag)
+{
+    unsigned index = 0;
+
+    index = Network_Port_Instance_To_Index(instance);
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        Object_List[index].Changes_Pending = flag;
+    } else
+        return false;
+
+    return true;
+}
+
+/**
+ * @brief For a given object instance-number, gets the MS/TP Max_Master value
+ * @param  object_instance - object-instance number of the object
+ * @return MS/TP Max_Master value
+ */
+uint8_t Network_Port_MSTP_Max_Master(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Max_Master = dlmstp_max_master();
+
+    return Object_List[0].Max_Master;
+}
+
+/**
+ * For a given object instance-number, sets the MS/TP Max_Master value
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  value - MS/TP Max_Master value 0..127
+ *
+ * @return  true if values are within range and property is set.
+ */
+bool Network_Port_MSTP_Max_Master_Set(uint32_t object_instance, uint8_t value)
+{
+    bool status = false;
+
+    (void)object_instance;
+    if (value <= dlmstp_max_master_limit()) {
+        Object_List[0].Max_Master = value;
+        Object_List[0].Changes_Pending = true;
+        status = true;
+    }
+
+    return status;
+}
+
+/**
+ * For a given object instance-number, gets the MS/TP Max_Info_Frames value
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return MS/TP Max_Info_Frames value
+ */
+uint8_t Network_Port_MSTP_Max_Info_Frames(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Max_Info_Frames = dlmstp_max_info_frames();
+
+    return Object_List[0].Max_Info_Frames;
+}
+
+/**
+ * For a given object instance-number, sets the MS/TP Max_Info_Frames value
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  value - MS/TP Max_Info_Frames value 0..255
+ *
+ * @return  true if values are within range and property is set.
+ */
+bool Network_Port_MSTP_Max_Info_Frames_Set(
+    uint32_t object_instance, uint8_t value)
+{
+    bool status = false;
+
+    (void)object_instance;
+    if (value <= dlmstp_max_info_frames_limit()) {
+        Object_List[0].Max_Info_Frames = value;
+        Object_List[0].Changes_Pending = true;
+        status = true;
+    }
+
+    return status;
+}
+
+/**
+ * ReadProperty handler for this object.  For the given ReadProperty
+ * data, the application_data is loaded or the error flags are set.
+ *
+ * @param  rpdata - BACNET_READ_PROPERTY_DATA data, including
+ * requested data and space for the reply, or error response.
+ *
+ * @return number of APDU bytes in the response, or
+ * BACNET_STATUS_ERROR on error.
+ */
+int Network_Port_Read_Property(BACNET_READ_PROPERTY_DATA *rpdata)
+{
+    int apdu_len = 0;
+    BACNET_BIT_STRING bit_string;
+    BACNET_OCTET_STRING octet_string;
+    BACNET_CHARACTER_STRING char_string;
+    uint8_t *apdu = NULL;
+
+    if ((rpdata == NULL) || (rpdata->application_data == NULL) ||
+        (rpdata->application_data_len == 0)) {
+        return 0;
+    }
+    apdu = rpdata->application_data;
+    switch (rpdata->object_property) {
+        case PROP_OBJECT_IDENTIFIER:
+            apdu_len = encode_application_object_id(
+                &apdu[0], OBJECT_NETWORK_PORT, rpdata->object_instance);
+            break;
+        case PROP_OBJECT_NAME:
+            Network_Port_Object_Name(rpdata->object_instance, &char_string);
+            apdu_len =
+                encode_application_character_string(&apdu[0], &char_string);
+            break;
+        case PROP_OBJECT_TYPE:
+            apdu_len =
+                encode_application_enumerated(&apdu[0], OBJECT_NETWORK_PORT);
+            break;
+        case PROP_STATUS_FLAGS:
+            bitstring_init(&bit_string);
+            bitstring_set_bit(&bit_string, STATUS_FLAG_IN_ALARM, false);
+            if (Network_Port_Reliability(rpdata->object_instance) ==
+                RELIABILITY_NO_FAULT_DETECTED) {
+                bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, false);
+            } else {
+                bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, true);
+            }
+            bitstring_set_bit(&bit_string, STATUS_FLAG_OVERRIDDEN, false);
+            if (Network_Port_Out_Of_Service(rpdata->object_instance)) {
+                bitstring_set_bit(
+                    &bit_string, STATUS_FLAG_OUT_OF_SERVICE, true);
+            } else {
+                bitstring_set_bit(
+                    &bit_string, STATUS_FLAG_OUT_OF_SERVICE, false);
+            }
+            apdu_len = encode_application_bitstring(&apdu[0], &bit_string);
+            break;
+        case PROP_RELIABILITY:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Reliability(rpdata->object_instance));
+            break;
+        case PROP_OUT_OF_SERVICE:
+            apdu_len = encode_application_boolean(
+                &apdu[0], Network_Port_Out_Of_Service(rpdata->object_instance));
+            break;
+        case PROP_NETWORK_TYPE:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Type(rpdata->object_instance));
+            break;
+        case PROP_PROTOCOL_LEVEL:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], BACNET_PROTOCOL_LEVEL_PHYSICAL);
+            break;
+        case PROP_NETWORK_NUMBER:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_Network_Number(rpdata->object_instance));
+            break;
+        case PROP_NETWORK_NUMBER_QUALITY:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Quality(rpdata->object_instance));
+            break;
+        case PROP_MAC_ADDRESS:
+            Network_Port_MAC_Address(rpdata->object_instance, &octet_string);
+            apdu_len = encode_application_octet_string(&apdu[0], &octet_string);
+            break;
+        case PROP_MAX_APDU_LENGTH_ACCEPTED:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_APDU_Length(rpdata->object_instance));
+            break;
+        case PROP_LINK_SPEED:
+            apdu_len = encode_application_real(
+                &apdu[0], Network_Port_Link_Speed(rpdata->object_instance));
+            break;
+        case PROP_CHANGES_PENDING:
+            apdu_len = encode_application_boolean(&apdu[0],
+                Network_Port_Changes_Pending(rpdata->object_instance));
+            break;
+        case PROP_APDU_LENGTH:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_APDU_Length(rpdata->object_instance));
+            break;
+        case PROP_MAX_MASTER:
+            apdu_len = encode_application_unsigned(&apdu[0],
+                Network_Port_MSTP_Max_Master(rpdata->object_instance));
+            break;
+        case PROP_MAX_INFO_FRAMES:
+            apdu_len = encode_application_unsigned(&apdu[0],
+                Network_Port_MSTP_Max_Info_Frames(rpdata->object_instance));
+            break;
+        default:
+            rpdata->error_class = ERROR_CLASS_PROPERTY;
+            rpdata->error_code = ERROR_CODE_UNKNOWN_PROPERTY;
+            apdu_len = BACNET_STATUS_ERROR;
+            break;
+    }
+
+    return apdu_len;
+}
+
+/**
+ * WriteProperty handler for this object.  For the given WriteProperty
+ * data, the application_data is loaded or the error flags are set.
+ *
+ * @param  wp_data - BACNET_WRITE_PROPERTY_DATA data, including
+ * requested data and space for the reply, or error response.
+ *
+ * @return false if an error is loaded, true if no errors
+ */
+bool Network_Port_Write_Property(BACNET_WRITE_PROPERTY_DATA *wp_data)
+{
+    bool status = false; /* return value */
+    int len = 0;
+    BACNET_APPLICATION_DATA_VALUE value;
+
+    if (!Network_Port_Valid_Instance(wp_data->object_instance)) {
+        wp_data->error_class = ERROR_CLASS_OBJECT;
+        wp_data->error_code = ERROR_CODE_UNKNOWN_OBJECT;
+        return false;
+    }
+    /* decode the some of the request */
+    len = bacapp_decode_application_data(
+        wp_data->application_data, wp_data->application_data_len, &value);
+    if (len < 0) {
+        /* error while decoding - a value larger than we can handle */
+        wp_data->error_class = ERROR_CLASS_PROPERTY;
+        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+        return false;
+    }
+    if ((wp_data->object_property != PROP_LINK_SPEEDS) &&
+        (wp_data->object_property != PROP_IP_DNS_SERVER) &&
+        (wp_data->object_property != PROP_IPV6_DNS_SERVER) &&
+        (wp_data->object_property != PROP_EVENT_MESSAGE_TEXTS) &&
+        (wp_data->object_property != PROP_EVENT_MESSAGE_TEXTS_CONFIG) &&
+        (wp_data->object_property != PROP_TAGS) &&
+        (wp_data->array_index != BACNET_ARRAY_ALL)) {
+        /*  only array properties can have array options */
+        wp_data->error_class = ERROR_CLASS_PROPERTY;
+        wp_data->error_code = ERROR_CODE_PROPERTY_IS_NOT_AN_ARRAY;
+        return false;
+    }
+    /* FIXME: len < application_data_len: more data? */
+    switch (wp_data->object_property) {
+        case PROP_MAX_MASTER:
+            if (value.tag == BACNET_APPLICATION_TAG_UNSIGNED_INT) {
+                if (value.type.Unsigned_Int <= 255) {
+                    status = Network_Port_MSTP_Max_Master_Set(
+                        wp_data->object_instance, value.type.Unsigned_Int);
+                    if (!status) {
+                        wp_data->error_class = ERROR_CLASS_PROPERTY;
+                        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                    }
+                } else {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_MAX_INFO_FRAMES:
+            if (value.tag == BACNET_APPLICATION_TAG_UNSIGNED_INT) {
+                if (value.type.Unsigned_Int <= 255) {
+                    status = Network_Port_MSTP_Max_Info_Frames_Set(
+                        wp_data->object_instance, value.type.Unsigned_Int);
+                    if (!status) {
+                        wp_data->error_class = ERROR_CLASS_PROPERTY;
+                        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                    }
+                    status = true;
+                } else {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_LINK_SPEED:
+            if (value.tag == BACNET_APPLICATION_TAG_REAL) {
+                if (!Network_Port_Link_Speed_Set(
+                        wp_data->object_instance, value.type.Real)) {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+                status = true;
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_MAC_ADDRESS:
+            if (value.tag == BACNET_APPLICATION_TAG_OCTET_STRING) {
+                if (!Network_Port_MAC_Address_Set(wp_data->object_instance,
+                        value.type.Octet_String.value,
+                        value.type.Octet_String.length)) {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+                status = true;
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_OBJECT_IDENTIFIER:
+        case PROP_OBJECT_NAME:
+        case PROP_OBJECT_TYPE:
+        case PROP_STATUS_FLAGS:
+        case PROP_RELIABILITY:
+        case PROP_OUT_OF_SERVICE:
+        case PROP_NETWORK_TYPE:
+        case PROP_PROTOCOL_LEVEL:
+        case PROP_NETWORK_NUMBER:
+        case PROP_NETWORK_NUMBER_QUALITY:
+        case PROP_MAX_APDU_LENGTH_ACCEPTED:
+        case PROP_CHANGES_PENDING:
+        case PROP_APDU_LENGTH:
+            wp_data->error_class = ERROR_CLASS_PROPERTY;
+            wp_data->error_code = ERROR_CODE_WRITE_ACCESS_DENIED;
+            break;
+        default:
+            wp_data->error_class = ERROR_CLASS_PROPERTY;
+            wp_data->error_code = ERROR_CODE_UNKNOWN_PROPERTY;
+            break;
+    }
+
+    return status;
+}
+
+/**
+ * Initializes the Network Port object data
+ */
+void Network_Port_Init(void)
+{
+    Object_List[0].Changes_Pending = false;
+    Object_List[0].MAC_Address[0] = dlmstp_mac_address();
+    Object_List[0].Max_Master = dlmstp_max_master();
+    Object_List[0].Max_Info_Frames = dlmstp_max_info_frames();
+    Object_List[0].Link_Speed = rs485_baud_rate();
+}
diff --git a/ports/stm32f4xx/device.c b/ports/stm32f4xx/device.c
index d2c37195..8cfd22f9 100644
--- a/ports/stm32f4xx/device.c
+++ b/ports/stm32f4xx/device.c
@@ -37,7 +37,9 @@
 #include "bacnet/version.h"
 #include "bacnet/basic/services.h"
 /* objects */
+#if (BACNET_PROTOCOL_REVISION >= 17)
 #include "bacnet/basic/object/netport.h"
+#endif
 #include "bacnet/basic/object/device.h"
 
 /* forward prototype */
@@ -54,20 +56,19 @@ static struct my_object_functions {
     read_property_function Object_Read_Property;
     write_property_function Object_Write_Property;
     rpm_property_lists_function Object_RPM_List;
-} Object_Table[] = { { OBJECT_DEVICE, NULL, /* don't init - recursive! */
-                         Device_Count, Device_Index_To_Instance,
-                         Device_Valid_Object_Instance_Number,
-                         Device_Object_Name, Device_Read_Property_Local,
-                         Device_Write_Property_Local, Device_Property_Lists },
-    {
+} Object_Table[] = {
+    { OBJECT_DEVICE, NULL, /* don't init - recursive! */
+        Device_Count, Device_Index_To_Instance,
+        Device_Valid_Object_Instance_Number,
+        Device_Object_Name, Device_Read_Property_Local,
+        Device_Write_Property_Local, Device_Property_Lists },
 #if (BACNET_PROTOCOL_REVISION >= 17)
-        OBJECT_NETWORK_PORT, Network_Port_Init, Network_Port_Count,
+    { OBJECT_NETWORK_PORT, Network_Port_Init, Network_Port_Count,
         Network_Port_Index_To_Instance, Network_Port_Valid_Instance,
         Network_Port_Object_Name, Network_Port_Read_Property,
         Network_Port_Write_Property, Network_Port_Property_Lists },
-    {
 #endif
-        MAX_BACNET_OBJECT_TYPE, NULL, NULL, NULL, NULL, NULL, NULL, NULL } };
+    { MAX_BACNET_OBJECT_TYPE, NULL, NULL, NULL, NULL, NULL, NULL, NULL } };
 
 /* note: you really only need to define variables for
    properties that are writable or that may change.
diff --git a/ports/stm32f4xx/netport.c b/ports/stm32f4xx/netport.c
index 8164461a..3a2899a6 100644
--- a/ports/stm32f4xx/netport.c
+++ b/ports/stm32f4xx/netport.c
@@ -746,95 +746,3 @@ void Network_Port_Init(void)
     Object_List[0].Max_Info_Frames = dlmstp_max_info_frames();
     Object_List[0].Link_Speed = rs485_baud_rate();
 }
-
-#ifdef BACNET_UNIT_TEST
-#include <assert.h>
-#include <string.h>
-#include "ctest.h"
-
-bool WPValidateArgType(BACNET_APPLICATION_DATA_VALUE *pValue,
-    uint8_t ucExpectedTag,
-    BACNET_ERROR_CLASS *pErrorClass,
-    BACNET_ERROR_CODE *pErrorCode)
-{
-    pValue = pValue;
-    ucExpectedTag = ucExpectedTag;
-    pErrorClass = pErrorClass;
-    pErrorCode = pErrorCode;
-
-    return false;
-}
-
-void test_network_port(Test *pTest)
-{
-    uint8_t apdu[MAX_APDU] = { 0 };
-    int len = 0;
-    int test_len = 0;
-    BACNET_READ_PROPERTY_DATA rpdata;
-    /* for decode value data */
-    BACNET_APPLICATION_DATA_VALUE value;
-    const int *pRequired = NULL;
-    const int *pOptional = NULL;
-    const int *pProprietary = NULL;
-    unsigned count = 0;
-    unsigned index = 0;
-
-    Network_Port_init();
-    count = Network_Port_Count();
-    for (index = 0; index < count; index++) {
-        rpdata.application_data = &apdu[0];
-        rpdata.application_data_len = sizeof(apdu);
-        rpdata.object_type = OBJECT_NETWORK_PORT;
-        rpdata.object_instance = Network_Port_Index_To_Instance(index);
-        Network_Port_Property_Lists(&pRequired, &pOptional, &pProprietary);
-        while ((*pRequired) != -1) {
-            rpdata.object_property = *pRequired;
-            rpdata.array_index = BACNET_ARRAY_ALL;
-            len = Network_Port_Read_Property(&rpdata);
-            ct_test(pTest, len != 0);
-            test_len = bacapp_decode_application_data(rpdata.application_data,
-                (uint8_t)rpdata.application_data_len, &value);
-            ct_test(pTest, test_len >= 0);
-            if (test_len < 0) {
-                printf("<decode failed!>\n");
-            }
-            pRequired++;
-        }
-        while ((*pOptional) != -1) {
-            rpdata.object_property = *pOptional;
-            rpdata.array_index = BACNET_ARRAY_ALL;
-            len = Network_Port_Read_Property(&rpdata);
-            ct_test(pTest, len != 0);
-            test_len = bacapp_decode_application_data(rpdata.application_data,
-                (uint8_t)rpdata.application_data_len, &value);
-            ct_test(pTest, test_len >= 0);
-            if (test_len < 0) {
-                printf("<decode failed!>\n");
-            }
-            pOptional++;
-        }
-    }
-
-    return;
-}
-
-#ifdef TEST_NETWORK_PORT
-int main(void)
-{
-    Test *pTest;
-    bool rc;
-
-    pTest = ct_create("BACnet Network Port", NULL);
-    /* individual tests */
-    rc = ct_addTestFunction(pTest, test_network_port);
-    assert(rc);
-
-    ct_setStream(pTest, stdout);
-    ct_run(pTest);
-    (void)ct_report(pTest);
-    ct_destroy(pTest);
-
-    return 0;
-}
-#endif
-#endif /* TEST */
diff --git a/ports/xplained/bacnet.cproj b/ports/xplained/bacnet.cproj
index c0d840b1..08e7bfb5 100644
--- a/ports/xplained/bacnet.cproj
+++ b/ports/xplained/bacnet.cproj
@@ -696,6 +696,9 @@
     <Compile Include="device.c">
       <SubType>compile</SubType>
     </Compile>
+    <Compile Include="netport.c">
+      <SubType>compile</SubType>
+    </Compile>
     <Compile Include="dlmstp.c">
       <SubType>compile</SubType>
       <CustomCompilationSetting Condition="'$(Configuration)' == 'Debug'">
diff --git a/ports/xplained/device.c b/ports/xplained/device.c
index 4ab69bc6..6a948e68 100644
--- a/ports/xplained/device.c
+++ b/ports/xplained/device.c
@@ -43,6 +43,9 @@
 /* objects */
 #include "bacnet/basic/object/device.h"
 #include "bacnet/basic/object/ai.h"
+#if (BACNET_PROTOCOL_REVISION >= 17)
+#include "bacnet/basic/object/netport.h"
+#endif
 
 /* forward prototype */
 int Device_Read_Property_Local(BACNET_READ_PROPERTY_DATA *rpdata);
@@ -71,6 +74,12 @@ static struct my_object_functions {
         Analog_Input_Object_Name, Analog_Input_Read_Property,
         Analog_Input_Write_Property, Analog_Input_Property_Lists, NULL, NULL,
         NULL },
+#if (BACNET_PROTOCOL_REVISION >= 17)
+    { OBJECT_NETWORK_PORT, Network_Port_Init, Network_Port_Count,
+        Network_Port_Index_To_Instance, Network_Port_Valid_Instance,
+        Network_Port_Object_Name, Network_Port_Read_Property,
+        Network_Port_Write_Property, Network_Port_Property_Lists },
+#endif
     { MAX_BACNET_OBJECT_TYPE, NULL, NULL, NULL, NULL, NULL, NULL, NULL }
 };
 
diff --git a/ports/xplained/dlmstp.c b/ports/xplained/dlmstp.c
index 122c956f..2f8beb2f 100644
--- a/ports/xplained/dlmstp.c
+++ b/ports/xplained/dlmstp.c
@@ -1470,3 +1470,13 @@ bool dlmstp_sole_master(void)
 
     return false;
 }
+
+uint8_t dlmstp_max_info_frames_limit(void)
+{
+    return MSTP_PDU_PACKET_COUNT;
+}
+
+uint8_t dlmstp_max_master_limit(void)
+{
+    return 127;
+}
diff --git a/ports/xplained/netport.c b/ports/xplained/netport.c
new file mode 100644
index 00000000..3a2899a6
--- /dev/null
+++ b/ports/xplained/netport.c
@@ -0,0 +1,748 @@
+/**
+ * @file
+ * @author Steve Karg
+ * @date 2016
+ * @brief Network port objects, customize for your use
+ *
+ * @section DESCRIPTION
+ *
+ * The Network Port object provides access to the configuration
+ * and properties of network ports of a device.
+ *
+ * @section LICENSE
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include "bacnet/config.h"
+#include "bacnet/basic/binding/address.h"
+#include "bacnet/bacdef.h"
+#include "bacnet/bacapp.h"
+#include "bacnet/bacdcode.h"
+#include "bacnet/npdu.h"
+#include "bacnet/apdu.h"
+#include "bacnet/basic/object/device.h"
+/* MS/TP specific */
+#include "bacnet/datalink/dlmstp.h"
+#include "rs485.h"
+//#include "nvdata.h"
+/* me */
+#include "bacnet/basic/object/netport.h"
+
+/* our local object data */
+struct object_data {
+    bool Changes_Pending : 1;
+    uint8_t MAC_Address[1];
+    uint8_t Max_Master;
+    uint8_t Max_Info_Frames;
+    float Link_Speed;
+};
+
+/* this object example only supports 1 instance */
+#define BACNET_NETWORK_PORTS_MAX 1
+struct object_data Object_List[BACNET_NETWORK_PORTS_MAX];
+/* instance number - can be overridden */
+#ifndef BACNET_NETWORK_PORT_INSTANCE
+#define BACNET_NETWORK_PORT_INSTANCE 1
+#endif
+
+/* These three arrays are used by the ReadPropertyMultiple handler */
+static const int Network_Port_Properties_Required[] = { PROP_OBJECT_IDENTIFIER,
+    PROP_OBJECT_NAME, PROP_OBJECT_TYPE, PROP_STATUS_FLAGS, PROP_RELIABILITY,
+    PROP_OUT_OF_SERVICE, PROP_NETWORK_TYPE, PROP_PROTOCOL_LEVEL,
+    PROP_NETWORK_NUMBER, PROP_NETWORK_NUMBER_QUALITY, PROP_CHANGES_PENDING,
+    PROP_APDU_LENGTH, PROP_LINK_SPEED, -1 };
+
+static const int Network_Port_Properties_Optional[] = { PROP_MAC_ADDRESS,
+    PROP_MAX_MASTER, PROP_MAX_INFO_FRAMES, -1 };
+
+static const int Network_Port_Properties_Proprietary[] = { -1 };
+
+/**
+ * Returns the list of required, optional, and proprietary properties.
+ * Used by ReadPropertyMultiple service.
+ *
+ * @param object_instance - object-instance number of the object
+ * @param pRequired - pointer to list of int terminated by -1, of
+ * BACnet required properties for this object.
+ * @param pOptional - pointer to list of int terminated by -1, of
+ * BACnet optkional properties for this object.
+ * @param pProprietary - pointer to list of int terminated by -1, of
+ * BACnet proprietary properties for this object.
+ */
+void Network_Port_Property_List(uint32_t object_instance,
+    const int **pRequired,
+    const int **pOptional,
+    const int **pProprietary)
+{
+    (void)object_instance;
+    if (pRequired) {
+        *pRequired = Network_Port_Properties_Required;
+    }
+    if (pOptional) {
+        *pOptional = Network_Port_Properties_Optional;
+    }
+    if (pProprietary) {
+        *pProprietary = Network_Port_Properties_Proprietary;
+    }
+
+    return;
+}
+
+/**
+ * Returns the list of required, optional, and proprietary properties.
+ * Used by ReadPropertyMultiple service.
+ *
+ * @param pRequired - pointer to list of int terminated by -1, of
+ * BACnet required properties for this object.
+ * @param pOptional - pointer to list of int terminated by -1, of
+ * BACnet optkional properties for this object.
+ * @param pProprietary - pointer to list of int terminated by -1, of
+ * BACnet proprietary properties for this object.
+ */
+void Network_Port_Property_Lists(
+    const int **pRequired, const int **pOptional, const int **pProprietary)
+{
+    Network_Port_Property_List(
+        BACNET_NETWORK_PORT_INSTANCE, pRequired, pOptional, pProprietary);
+}
+
+/**
+ * For a given object instance-number, loads the object-name into
+ * a characterstring. Note that the object name must be unique
+ * within this device.
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  object_name - holds the object-name retrieved
+ *
+ * @return  true if object-name was retrieved
+ */
+bool Network_Port_Object_Name(
+    uint32_t object_instance, BACNET_CHARACTER_STRING *object_name)
+{
+    bool status = false;
+
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        status = characterstring_init_ansi(object_name, "NP-1");
+    }
+
+    return status;
+}
+
+/**
+ * Determines if a given Network Port instance is valid
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  true if the instance is valid, and false if not
+ */
+bool Network_Port_Valid_Instance(uint32_t object_instance)
+{
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        return true;
+    }
+
+    return false;
+}
+
+/**
+ * Determines the number of Network Port objects
+ *
+ * @return  Number of Network Port objects
+ */
+unsigned Network_Port_Count(void)
+{
+    return BACNET_NETWORK_PORTS_MAX;
+}
+
+/**
+ * Determines the object instance-number for a given 0..N index
+ * of Network Port objects where N is Network_Port_Count().
+ *
+ * @param index - 0..BACNET_NETWORK_PORTS_MAX value
+ *
+ * @return object instance-number for the given index, or BACNET_MAX_INSTANCE
+ * for an invalid index.
+ */
+uint32_t Network_Port_Index_To_Instance(unsigned index)
+{
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        return BACNET_NETWORK_PORT_INSTANCE;
+    }
+
+    return BACNET_MAX_INSTANCE;
+}
+
+/**
+ * For a given object instance-number, determines a 0..N index
+ * of Network Port objects where N is Network_Port_Count().
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  index for the given instance-number, or BACNET_NETWORK_PORTS_MAX
+ * if not valid.
+ */
+unsigned Network_Port_Instance_To_Index(uint32_t object_instance)
+{
+    if (object_instance == BACNET_NETWORK_PORT_INSTANCE) {
+        return 0;
+    }
+
+    return BACNET_NETWORK_PORTS_MAX;
+}
+
+/**
+ * For a given object instance-number, returns the out-of-service
+ * property value
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return  out-of-service property value
+ */
+bool Network_Port_Out_Of_Service(uint32_t object_instance)
+{
+    (void)object_instance;
+    return false;
+}
+
+/**
+ * For a given object instance-number, gets the reliability.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return reliability value
+ */
+BACNET_RELIABILITY Network_Port_Reliability(uint32_t object_instance)
+{
+    (void)object_instance;
+    return RELIABILITY_NO_FAULT_DETECTED;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Type.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return BACnet network type value
+ */
+uint8_t Network_Port_Type(uint32_t object_instance)
+{
+    (void)object_instance;
+    return PORT_TYPE_MSTP;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Number.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return BACnet network type value
+ */
+uint16_t Network_Port_Network_Number(uint32_t object_instance)
+{
+    (void)object_instance;
+    /* A Network_Number of 0 indicates that the Network_Number
+       is not known or cannot be determined. */
+    return 0;
+}
+
+/**
+ * For a given object instance-number, gets the quality property
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return quality property value
+ */
+BACNET_PORT_QUALITY Network_Port_Quality(uint32_t object_instance)
+{
+    (void)object_instance;
+    return PORT_QUALITY_CONFIGURED;
+}
+
+/**
+ * For a given object instance-number, loads the mac-address into
+ * an octet string.
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  mac_address - holds the mac-address retrieved
+ *
+ * @return  true if mac-address was retrieved
+ */
+bool Network_Port_MAC_Address(
+    uint32_t object_instance, BACNET_OCTET_STRING *mac_address)
+{
+    (void)object_instance;
+    Object_List[0].MAC_Address[0] = dlmstp_mac_address();
+
+    return octetstring_init(mac_address, Object_List[0].MAC_Address, 1);
+}
+
+/**
+ * @brief For a given object instance-number, set the mac-address and length
+ * @param  object_instance - object-instance number of the object
+ * @param  mac_src - holds the MAC address to be written
+ * @param  mac_len - number of bytes in the MAC address
+ * @return  true if object-name was set
+ */
+bool Network_Port_MAC_Address_Set(
+    uint32_t object_instance, uint8_t *mac_src, uint8_t mac_len)
+{
+    if (mac_len == 1) {
+        Object_List[0].MAC_Address[0] = mac_src[0];
+        Object_List[0].Changes_Pending = true;
+        return true;
+    }
+
+    return false;
+}
+
+/**
+ * For a given object instance-number, gets the BACnet Network Number.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return APDU length for this network port
+ */
+uint16_t Network_Port_APDU_Length(uint32_t object_instance)
+{
+    (void)object_instance;
+    return MAX_APDU;
+}
+
+/**
+ * For a given object instance-number, gets the network communication rate
+ * as the number of bits per second. A value of 0 indicates an unknown
+ * communication rate.
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return Link_Speed for this network port, or 0 if unknown
+ */
+float Network_Port_Link_Speed(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Link_Speed = rs485_baud_rate();
+
+    return Object_List[0].Link_Speed;
+}
+
+/**
+ * @brief Set the device link speed (baud rate)
+ * @param object_instance	The object instance number of the object
+ * @param value				The new link speed value
+ * @return  true if value was set
+ */
+bool Network_Port_Link_Speed_Set(uint32_t object_instance, float value)
+{
+    bool status = false;
+    uint32_t baud = (uint32_t)value;
+
+    switch (baud) {
+        case 9600:
+        case 19200:
+        case 38400:
+        case 57600:
+        case 76800:
+        case 115200:
+            Object_List[0].Link_Speed = value;
+            Object_List[0].Changes_Pending = true;
+            status = true;
+            break;
+    }
+
+    return status;
+}
+
+/**
+ * @brief For a given object instance-number, returns the changes-pending flag
+ * @param  object_instance - object-instance number of the object
+ * @return  changes-pending property value
+ */
+bool Network_Port_Changes_Pending(uint32_t object_instance)
+{
+    bool flag = false;
+    unsigned index = 0;
+
+    index = Network_Port_Instance_To_Index(object_instance);
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        flag = Object_List[index].Changes_Pending;
+    }
+
+    return flag;
+}
+
+/**
+ * @brief For a given object instance-number, sets the changes-pending flag
+ * @param object_instance - object-instance number of the object
+ * @param flag - true=changes pending, false=no changes pending
+ * @return true if flag was set
+ */
+bool Network_Port_Changes_Pending_Set(uint32_t instance, bool flag)
+{
+    unsigned index = 0;
+
+    index = Network_Port_Instance_To_Index(instance);
+    if (index < BACNET_NETWORK_PORTS_MAX) {
+        Object_List[index].Changes_Pending = flag;
+    } else
+        return false;
+
+    return true;
+}
+
+/**
+ * @brief For a given object instance-number, gets the MS/TP Max_Master value
+ * @param  object_instance - object-instance number of the object
+ * @return MS/TP Max_Master value
+ */
+uint8_t Network_Port_MSTP_Max_Master(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Max_Master = dlmstp_max_master();
+
+    return Object_List[0].Max_Master;
+}
+
+/**
+ * For a given object instance-number, sets the MS/TP Max_Master value
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  value - MS/TP Max_Master value 0..127
+ *
+ * @return  true if values are within range and property is set.
+ */
+bool Network_Port_MSTP_Max_Master_Set(uint32_t object_instance, uint8_t value)
+{
+    bool status = false;
+
+    (void)object_instance;
+    if (value <= dlmstp_max_master_limit()) {
+        Object_List[0].Max_Master = value;
+        Object_List[0].Changes_Pending = true;
+        status = true;
+    }
+
+    return status;
+}
+
+/**
+ * For a given object instance-number, gets the MS/TP Max_Info_Frames value
+ *
+ * @param  object_instance - object-instance number of the object
+ *
+ * @return MS/TP Max_Info_Frames value
+ */
+uint8_t Network_Port_MSTP_Max_Info_Frames(uint32_t object_instance)
+{
+    (void)object_instance;
+    Object_List[0].Max_Info_Frames = dlmstp_max_info_frames();
+
+    return Object_List[0].Max_Info_Frames;
+}
+
+/**
+ * For a given object instance-number, sets the MS/TP Max_Info_Frames value
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  value - MS/TP Max_Info_Frames value 0..255
+ *
+ * @return  true if values are within range and property is set.
+ */
+bool Network_Port_MSTP_Max_Info_Frames_Set(
+    uint32_t object_instance, uint8_t value)
+{
+    bool status = false;
+
+    (void)object_instance;
+    if (value <= dlmstp_max_info_frames_limit()) {
+        Object_List[0].Max_Info_Frames = value;
+        Object_List[0].Changes_Pending = true;
+        status = true;
+    }
+
+    return status;
+}
+
+/**
+ * ReadProperty handler for this object.  For the given ReadProperty
+ * data, the application_data is loaded or the error flags are set.
+ *
+ * @param  rpdata - BACNET_READ_PROPERTY_DATA data, including
+ * requested data and space for the reply, or error response.
+ *
+ * @return number of APDU bytes in the response, or
+ * BACNET_STATUS_ERROR on error.
+ */
+int Network_Port_Read_Property(BACNET_READ_PROPERTY_DATA *rpdata)
+{
+    int apdu_len = 0;
+    BACNET_BIT_STRING bit_string;
+    BACNET_OCTET_STRING octet_string;
+    BACNET_CHARACTER_STRING char_string;
+    uint8_t *apdu = NULL;
+
+    if ((rpdata == NULL) || (rpdata->application_data == NULL) ||
+        (rpdata->application_data_len == 0)) {
+        return 0;
+    }
+    apdu = rpdata->application_data;
+    switch (rpdata->object_property) {
+        case PROP_OBJECT_IDENTIFIER:
+            apdu_len = encode_application_object_id(
+                &apdu[0], OBJECT_NETWORK_PORT, rpdata->object_instance);
+            break;
+        case PROP_OBJECT_NAME:
+            Network_Port_Object_Name(rpdata->object_instance, &char_string);
+            apdu_len =
+                encode_application_character_string(&apdu[0], &char_string);
+            break;
+        case PROP_OBJECT_TYPE:
+            apdu_len =
+                encode_application_enumerated(&apdu[0], OBJECT_NETWORK_PORT);
+            break;
+        case PROP_STATUS_FLAGS:
+            bitstring_init(&bit_string);
+            bitstring_set_bit(&bit_string, STATUS_FLAG_IN_ALARM, false);
+            if (Network_Port_Reliability(rpdata->object_instance) ==
+                RELIABILITY_NO_FAULT_DETECTED) {
+                bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, false);
+            } else {
+                bitstring_set_bit(&bit_string, STATUS_FLAG_FAULT, true);
+            }
+            bitstring_set_bit(&bit_string, STATUS_FLAG_OVERRIDDEN, false);
+            if (Network_Port_Out_Of_Service(rpdata->object_instance)) {
+                bitstring_set_bit(
+                    &bit_string, STATUS_FLAG_OUT_OF_SERVICE, true);
+            } else {
+                bitstring_set_bit(
+                    &bit_string, STATUS_FLAG_OUT_OF_SERVICE, false);
+            }
+            apdu_len = encode_application_bitstring(&apdu[0], &bit_string);
+            break;
+        case PROP_RELIABILITY:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Reliability(rpdata->object_instance));
+            break;
+        case PROP_OUT_OF_SERVICE:
+            apdu_len = encode_application_boolean(
+                &apdu[0], Network_Port_Out_Of_Service(rpdata->object_instance));
+            break;
+        case PROP_NETWORK_TYPE:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Type(rpdata->object_instance));
+            break;
+        case PROP_PROTOCOL_LEVEL:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], BACNET_PROTOCOL_LEVEL_PHYSICAL);
+            break;
+        case PROP_NETWORK_NUMBER:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_Network_Number(rpdata->object_instance));
+            break;
+        case PROP_NETWORK_NUMBER_QUALITY:
+            apdu_len = encode_application_enumerated(
+                &apdu[0], Network_Port_Quality(rpdata->object_instance));
+            break;
+        case PROP_MAC_ADDRESS:
+            Network_Port_MAC_Address(rpdata->object_instance, &octet_string);
+            apdu_len = encode_application_octet_string(&apdu[0], &octet_string);
+            break;
+        case PROP_MAX_APDU_LENGTH_ACCEPTED:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_APDU_Length(rpdata->object_instance));
+            break;
+        case PROP_LINK_SPEED:
+            apdu_len = encode_application_real(
+                &apdu[0], Network_Port_Link_Speed(rpdata->object_instance));
+            break;
+        case PROP_CHANGES_PENDING:
+            apdu_len = encode_application_boolean(&apdu[0],
+                Network_Port_Changes_Pending(rpdata->object_instance));
+            break;
+        case PROP_APDU_LENGTH:
+            apdu_len = encode_application_unsigned(
+                &apdu[0], Network_Port_APDU_Length(rpdata->object_instance));
+            break;
+        case PROP_MAX_MASTER:
+            apdu_len = encode_application_unsigned(&apdu[0],
+                Network_Port_MSTP_Max_Master(rpdata->object_instance));
+            break;
+        case PROP_MAX_INFO_FRAMES:
+            apdu_len = encode_application_unsigned(&apdu[0],
+                Network_Port_MSTP_Max_Info_Frames(rpdata->object_instance));
+            break;
+        default:
+            rpdata->error_class = ERROR_CLASS_PROPERTY;
+            rpdata->error_code = ERROR_CODE_UNKNOWN_PROPERTY;
+            apdu_len = BACNET_STATUS_ERROR;
+            break;
+    }
+
+    return apdu_len;
+}
+
+/**
+ * WriteProperty handler for this object.  For the given WriteProperty
+ * data, the application_data is loaded or the error flags are set.
+ *
+ * @param  wp_data - BACNET_WRITE_PROPERTY_DATA data, including
+ * requested data and space for the reply, or error response.
+ *
+ * @return false if an error is loaded, true if no errors
+ */
+bool Network_Port_Write_Property(BACNET_WRITE_PROPERTY_DATA *wp_data)
+{
+    bool status = false; /* return value */
+    int len = 0;
+    BACNET_APPLICATION_DATA_VALUE value;
+
+    if (!Network_Port_Valid_Instance(wp_data->object_instance)) {
+        wp_data->error_class = ERROR_CLASS_OBJECT;
+        wp_data->error_code = ERROR_CODE_UNKNOWN_OBJECT;
+        return false;
+    }
+    /* decode the some of the request */
+    len = bacapp_decode_application_data(
+        wp_data->application_data, wp_data->application_data_len, &value);
+    if (len < 0) {
+        /* error while decoding - a value larger than we can handle */
+        wp_data->error_class = ERROR_CLASS_PROPERTY;
+        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+        return false;
+    }
+    if ((wp_data->object_property != PROP_LINK_SPEEDS) &&
+        (wp_data->object_property != PROP_IP_DNS_SERVER) &&
+        (wp_data->object_property != PROP_IPV6_DNS_SERVER) &&
+        (wp_data->object_property != PROP_EVENT_MESSAGE_TEXTS) &&
+        (wp_data->object_property != PROP_EVENT_MESSAGE_TEXTS_CONFIG) &&
+        (wp_data->object_property != PROP_TAGS) &&
+        (wp_data->array_index != BACNET_ARRAY_ALL)) {
+        /*  only array properties can have array options */
+        wp_data->error_class = ERROR_CLASS_PROPERTY;
+        wp_data->error_code = ERROR_CODE_PROPERTY_IS_NOT_AN_ARRAY;
+        return false;
+    }
+    /* FIXME: len < application_data_len: more data? */
+    switch (wp_data->object_property) {
+        case PROP_MAX_MASTER:
+            if (value.tag == BACNET_APPLICATION_TAG_UNSIGNED_INT) {
+                if (value.type.Unsigned_Int <= 255) {
+                    status = Network_Port_MSTP_Max_Master_Set(
+                        wp_data->object_instance, value.type.Unsigned_Int);
+                    if (!status) {
+                        wp_data->error_class = ERROR_CLASS_PROPERTY;
+                        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                    }
+                } else {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_MAX_INFO_FRAMES:
+            if (value.tag == BACNET_APPLICATION_TAG_UNSIGNED_INT) {
+                if (value.type.Unsigned_Int <= 255) {
+                    status = Network_Port_MSTP_Max_Info_Frames_Set(
+                        wp_data->object_instance, value.type.Unsigned_Int);
+                    if (!status) {
+                        wp_data->error_class = ERROR_CLASS_PROPERTY;
+                        wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                    }
+                    status = true;
+                } else {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_LINK_SPEED:
+            if (value.tag == BACNET_APPLICATION_TAG_REAL) {
+                if (!Network_Port_Link_Speed_Set(
+                        wp_data->object_instance, value.type.Real)) {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+                status = true;
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_MAC_ADDRESS:
+            if (value.tag == BACNET_APPLICATION_TAG_OCTET_STRING) {
+                if (!Network_Port_MAC_Address_Set(wp_data->object_instance,
+                        value.type.Octet_String.value,
+                        value.type.Octet_String.length)) {
+                    wp_data->error_class = ERROR_CLASS_PROPERTY;
+                    wp_data->error_code = ERROR_CODE_VALUE_OUT_OF_RANGE;
+                }
+                status = true;
+            } else {
+                wp_data->error_class = ERROR_CLASS_PROPERTY;
+                wp_data->error_code = ERROR_CODE_INVALID_DATA_TYPE;
+            }
+            break;
+        case PROP_OBJECT_IDENTIFIER:
+        case PROP_OBJECT_NAME:
+        case PROP_OBJECT_TYPE:
+        case PROP_STATUS_FLAGS:
+        case PROP_RELIABILITY:
+        case PROP_OUT_OF_SERVICE:
+        case PROP_NETWORK_TYPE:
+        case PROP_PROTOCOL_LEVEL:
+        case PROP_NETWORK_NUMBER:
+        case PROP_NETWORK_NUMBER_QUALITY:
+        case PROP_MAX_APDU_LENGTH_ACCEPTED:
+        case PROP_CHANGES_PENDING:
+        case PROP_APDU_LENGTH:
+            wp_data->error_class = ERROR_CLASS_PROPERTY;
+            wp_data->error_code = ERROR_CODE_WRITE_ACCESS_DENIED;
+            break;
+        default:
+            wp_data->error_class = ERROR_CLASS_PROPERTY;
+            wp_data->error_code = ERROR_CODE_UNKNOWN_PROPERTY;
+            break;
+    }
+
+    return status;
+}
+
+/**
+ * Initializes the Network Port object data
+ */
+void Network_Port_Init(void)
+{
+    Object_List[0].Changes_Pending = false;
+    Object_List[0].MAC_Address[0] = dlmstp_mac_address();
+    Object_List[0].Max_Master = dlmstp_max_master();
+    Object_List[0].Max_Info_Frames = dlmstp_max_info_frames();
+    Object_List[0].Link_Speed = rs485_baud_rate();
+}
diff --git a/src/bacnet/basic/object/netport.c b/src/bacnet/basic/object/netport.c
index da1b933d..015bc3b9 100644
--- a/src/bacnet/basic/object/netport.c
+++ b/src/bacnet/basic/object/netport.c
@@ -40,6 +40,7 @@
 #include "bacnet/basic/binding/address.h"
 #include "bacnet/bacdef.h"
 #include "bacnet/bacapp.h"
+#include "bacnet/bacint.h"
 #include "bacnet/bacdcode.h"
 #include "bacnet/npdu.h"
 #include "bacnet/apdu.h"
@@ -599,7 +600,9 @@ bool Network_Port_MAC_Address(
             case PORT_TYPE_BIP:
                 memcpy(
                     &ip_mac[0], &Object_List[index].Network.IPv4.IP_Address, 4);
-                memcpy(&ip_mac[4], &Object_List[index].Network.IPv4.Port, 2);
+                /* convert port from host-byte-order to network-byte-order */
+                encode_unsigned16(&ip_mac[4],
+                    &Object_List[index].Network.IPv4.Port);
                 mac = &ip_mac[0];
                 mac_len = sizeof(ip_mac);
                 break;
diff --git a/src/bacnet/basic/service/h_rp.c b/src/bacnet/basic/service/h_rp.c
index a408b693..2c5705c2 100644
--- a/src/bacnet/basic/service/h_rp.c
+++ b/src/bacnet/basic/service/h_rp.c
@@ -39,6 +39,9 @@
 #include "bacnet/rp.h"
 /* basic objects, services, TSM, and datalink */
 #include "bacnet/basic/object/device.h"
+#if (BACNET_PROTOCOL_REVISION >= 17)
+#include "bacnet/basic/object/netport.h"
+#endif
 #include "bacnet/basic/tsm/tsm.h"
 #include "bacnet/basic/services.h"
 #include "bacnet/datalink/datalink.h"
@@ -112,16 +115,37 @@ void handler_read_property(uint8_t *service_request,
             fprintf(stderr, "RP: Bad Encoding.\n");
     #endif
         } else {
-            /* Test for case of indefinite Device object instance */
+            /* When the object-type in the Object Identifier parameter
+               contains the value DEVICE and the instance in the 'Object
+               Identifier' parameter contains the value 4194303, the responding
+               BACnet-user shall treat the Object Identifier as if it correctly
+               matched the local Device object. This allows the device instance
+               of a device that does not generate I-Am messages to be
+               determined. */
             if ((rpdata.object_type == OBJECT_DEVICE) &&
                 (rpdata.object_instance == BACNET_MAX_INSTANCE)) {
                 rpdata.object_instance = Device_Object_Instance_Number();
             }
-
+#if (BACNET_PROTOCOL_REVISION >= 17)
+            /* When the object-type in the Object Identifier parameter
+               contains the value NETWORK_PORT and the instance in the 'Object
+               Identifier' parameter contains the value 4194303, the responding
+               BACnet-user shall treat the Object Identifier as if it correctly
+               matched the local Network Port object representing the network
+               port through which the request was received. This allows the
+               network port instance of the network port that was used to
+               receive the request to be determined. */
+            if ((rpdata.object_type == OBJECT_NETWORK_PORT) &&
+                (rpdata.object_instance == BACNET_MAX_INSTANCE)) {
+                rpdata.object_instance = Network_Port_Index_To_Instance(0);
+            }
+#endif
             apdu_len = rp_ack_encode_apdu_init(
-                &Handler_Transmit_Buffer[npdu_len], service_data->invoke_id, &rpdata);
+                &Handler_Transmit_Buffer[npdu_len], service_data->invoke_id,
+                &rpdata);
             /* configure our storage */
-            rpdata.application_data = &Handler_Transmit_Buffer[npdu_len + apdu_len];
+            rpdata.application_data =
+                &Handler_Transmit_Buffer[npdu_len + apdu_len];
             rpdata.application_data_len =
                 sizeof(Handler_Transmit_Buffer) - (npdu_len + apdu_len);
             len = Device_Read_Property(&rpdata);
@@ -131,10 +155,11 @@ void handler_read_property(uint8_t *service_request,
                     &Handler_Transmit_Buffer[npdu_len + apdu_len]);
                 apdu_len += len;
                 if (apdu_len > service_data->max_resp) {
-                    /* too big for the sender - send an abort
-                     * Setting of error code needed here as read property processing may
-                     * have overriden the default set at start */
-                    rpdata.error_code = ERROR_CODE_ABORT_SEGMENTATION_NOT_SUPPORTED;
+                    /* too big for the sender - send an abort!
+                       Setting of error code needed here as read property
+                       processing may have overriden the default set at start */
+                    rpdata.error_code =
+                        ERROR_CODE_ABORT_SEGMENTATION_NOT_SUPPORTED;
                     len = BACNET_STATUS_ABORT;
         #if PRINT_ENABLED
                     fprintf(stderr, "RP: Message too large.\n");
diff --git a/src/bacnet/basic/service/h_rpm.c b/src/bacnet/basic/service/h_rpm.c
index f5145070..0511977c 100644
--- a/src/bacnet/basic/service/h_rpm.c
+++ b/src/bacnet/basic/service/h_rpm.c
@@ -41,6 +41,9 @@
 #include "bacnet/rpm.h"
 /* basic objects, services, TSM, and datalink */
 #include "bacnet/basic/object/device.h"
+#if (BACNET_PROTOCOL_REVISION >= 17)
+#include "bacnet/basic/object/netport.h"
+#endif
 #include "bacnet/basic/tsm/tsm.h"
 #include "bacnet/basic/services.h"
 #include "bacnet/datalink/datalink.h"
@@ -239,6 +242,21 @@ void handler_read_property_multiple(uint8_t *service_request,
                     (rpmdata.object_instance == BACNET_MAX_INSTANCE)) {
                     rpmdata.object_instance = Device_Object_Instance_Number();
                 }
+#if (BACNET_PROTOCOL_REVISION >= 17)
+                /* When the object-type in the Object Identifier parameter
+                   contains the value NETWORK_PORT and the instance in the
+                   'Object Identifier' parameter contains the value 4194303,
+                   the responding BACnet-user shall treat the Object Identifier
+                   as if it correctly matched the local Network Port object
+                   representing the network port through which the request was
+                   received. This allows the network port instance of the
+                   network port that was used to receive the request to be
+                   determined. */
+                if ((rpmdata.object_type == OBJECT_NETWORK_PORT) &&
+                    (rpmdata.object_instance == BACNET_MAX_INSTANCE)) {
+                    rpmdata.object_instance = Network_Port_Index_To_Instance(0);
+                }
+#endif
 
                 /* Stick this object id into the reply - if it will fit */
                 len = rpm_ack_encode_apdu_object_begin(&Temp_Buf[0], &rpmdata);