Removed old device twin versions

Author: gsteve88

articles/iot-hub/TOC.yml

@@ -284,25 +284,8 @@
           displayName: file upload, upload files
           href: how-to-file-upload.md
         - name: Get started with device twins
-          items:
-            - name: New version
-              displayName: New version
-              href: how-to-device-twins.md         
-            - name: CLI
-              displayName: device twins
-              href: device-twins-cli.md
-            - name: .NET
-              displayName: device twins
-              href: device-twins-dotnet.md
-            - name: Python
-              displayName: device twins
-              href: device-twins-python.md
-            - name: Node.js
-              displayName: device twins
-              href: device-twins-node.md
-            - name: Java
-              displayName: device twins
-              href: device-twins-java.md
+          displayName: device twins
+          href: how-to-device-twins.md   
         - name: Get started with module twins
           items:
             - name: Portal

articles/iot-hub/how-to-device-twins.md

@@ -60,6 +60,8 @@ This article shows you how to develop two types of applications:
 
   For more information about IoT Hub shared access policies and permissions, see [Access control and permissions](/azure/iot-hub/authenticate-authorize-sas).
 
+* If an application uses the MQTT protocol, make sure that **port 8883** is open in your firewall. The MQTT protocol communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see [Connecting to IoT Hub (MQTT)](../iot/iot-mqtt-connect-to-iot-hub.md#connecting-to-iot-hub).
+
 * Language SDK requirements:
   * **.NET SDK** - Requres Visual Studio.
   * **Python SDK** - [Python version 3.7 or later](https://www.python.org/downloads/) is recommended. Make sure to use the 32-bit or 64-bit installation as required by your setup. When prompted during the installation, make sure to add Python to your platform-specific environment variable.

includes/iot-hub-howto-device-twins-dotnet.md

@@ -61,7 +61,7 @@ _deviceClient = DeviceClient.CreateFromConnectionString(DeviceConnectionString,
 
 ### Retrieve a device twin and examine properties
 
-Call [GetTwinAsync](/dotnet/api/microsoft.azure.devices.client.deviceclient.gettwinasync?#microsoft-azure-devices-client-deviceclient-gettwinasync) to retrieve the current device twin properties. There are many [Twin](/dotnet/api/microsoft.azure.devices.shared.twin?) object [properties](/dotnet/api/microsoft.azure.devices.shared.twin?&branch=main#properties) that you can use to access specific areas of the Twin JSON data including Twin `Properties`, `Status`, `Tags`, and `Version`.
+Call [GetTwinAsync](/dotnet/api/microsoft.azure.devices.client.deviceclient.gettwinasync?#microsoft-azure-devices-client-deviceclient-gettwinasync) to retrieve the current device twin properties. There are many [Twin](/dotnet/api/microsoft.azure.devices.shared.twin?) object [properties](/dotnet/api/microsoft.azure.devices.shared.twin?&#properties) that you can use to access specific areas of the `Twin` JSON data including `Properties`, `Status`, `Tags`, and `Version`.
 
  This example retrieves device twin properties and prints the twin values in JSON format.
 
@@ -178,7 +178,7 @@ After making twin field updates, call [UpdateTwinAsync](/dotnet/api/microsoft.az
 
 Use the device twin [Tags](/dotnet/api/microsoft.azure.devices.shared.twin.tags?#microsoft-azure-devices-shared-twin-tags) property to read and write device tag information.
 
-##### Update using a Twin object
+##### Update tags using a twin object
 
 This example creates a `location` tag patch, assigns it to the `Twin` object using the `Tags` property, and then applies the patch using `UpdateTwinAsync`.
 

includes/iot-hub-howto-device-twins-node.md

@@ -13,7 +13,7 @@ ms.custom: mqtt, devx-track-js
 
 ## Overview
 
-This article describes how to use the [Azure IoT SDK for JavaScript](https://github.com/Azure/azure-iot-sdk-node) to create device and backend service application code for device twins.
+This article describes how to use the [Azure IoT SDK for Node.js](https://github.com/Azure/azure-iot-sdk-node) to create device and backend service application code for device twins.
 
 ## Create a device application
 
@@ -55,7 +55,7 @@ npm install azure-iot-device-mqtt --save
 
 For more information about the differences between MQTT, AMQP, and HTTPS support, see [Cloud-to-device communications guidance](../articles/iot-hub/iot-hub-devguide-c2d-guidance.md) and [Choose a communication protocol](../articles/iot-hub/iot-hub-devguide-protocols.md).
 
-### Create a Client module
+### Create a client module
 
 Create a `Client` module using the installed package.
 
@@ -65,7 +65,7 @@ For example:
 const Client = require('azure-iot-device').Client;
 ```
 
-### Create a Protocol module
+### Create a protocol module
 
 Create a `Protocol` module using an installed transport package.