Dell Wyse ThinOS Version 8.5 Administrator’s Guide

The WebSocket protocol enables two-way communication between the browser-based applications and the servers that does not rely on the multiple HTTP connections. The protocol consists of a handshake followed by basic message framing, layered over Transmission Control Protocol (TCP). The data is transferred immediately over a full-duplex single socket connection, allowing messages to be sent and received from both endpoints in real time.

As a pre-requisite, you must enable the WebSocket protocol on Windows Server 2016.

ThinOS behavior

• In the previous TS Gateway connection, the setup uses a two half-duplex communications between Terminal Server (TS) Gateway server and thin client.
• In the ThinOS version 8.5, the session connection setup uses a duplex communication between the TS Gateway and thin client.
  NOTE:TSG2 and TSG3 are downward compatible.
  If the WebSocket connection fails or the TS Gateway server or thin client version does not support WebSocket, then TSG3 or TSG2 is used.
• In comparison with TSG3, when the WebSocket handshake succeeds during the Create OUT Channel, the OUT Channel and IN Channel use the duplex communication between the TS Gateway and thin client. Therefore, the second HTTP 1.1 connection for IN Channel is not established.
• A single HTTPS configuration with the WebSocket protocol is a two-step process.
  1. On the thin client, a single HTTPS connection to TS gateway is configured. The thin client performs the handshake, and provides the authentication information and target server information.
  2. The thin client logs in to the session host server through the TS gateway connection.
  NOTE:You can capture the Network analysis file and check if the SslStream of the connection is upgraded to WebSocket.