The chat capability supported by the Remote Assistance Protocol allows the exchange of text messages between two computers that are in a Remote Assistance session. A chat virtual channel is created when the Remote Assistance connection is established and persists through the duration of the Remote Assistance connection.
Once the chat virtual channel is created, text messages can be transported in a duplex manner between the two computers. All the messages that are sent through a chat virtual channel are text messages. The chat virtual channel does not have any control messages.