2.5.21 Join a Chat Room

This use case, illustrated in the following diagram, describes how a protocol client can join a group chat room and post a chat message<32>.

Steps for joining a chat room

Figure 25: Steps for joining a chat room

References

Preconditions

  • The protocol clients are signed in, as described in section 2.5.5.

Steps

  1. The protocol client sends a SIP INVITE request to the protocol server to start a group chat session with protocol server.

  2. Group Chat Server accepts the incoming message with a SIP 200 response.

  3. The protocol client sends a SIP acknowledgment (ACK) message; the SIP dialog is now established.

  4. The protocol client requests the protocol server information by sending a "cmd:getserverinfo" command over a SIP INFO message, as described in [MS-XCCOSIP].

  5. The protocol server acknowledges the message from previous step with a SIP 200 response.

  6. The protocol server replies with a "rpl:getserverinfo" reply over a SIP INFO message, as described in [MS-XCCOSIP].

  7. The protocol client acknowledges the message from the previous step with a SIP 200 response.

  8. The protocol client requests joining a set of chat rooms by sending a "cmd:bjoin" command over a SIP INFO message, as described in [MS-XCCOSIP].

  9. The protocol server acknowledges the message from previous step with a SIP 200 response.

  10. The protocol server replies with a "rpl:bjoin" reply over a SIP INFO message, as described in [MS-XCCOSIP]. The chat session is now established.

  11. The protocol client acknowledges the message from the previous step with a SIP 200 response.

  12. The protocol server also sends the historic backchat to the protocol client by sending a "rpl:bccontext" reply over a SIP INFO message, as described in [MS-XCCOSIP].

  13. The protocol client acknowledges the message from the previous step with a SIP 200 response.

  14. The protocol client can post a chat to the room by sending a "grpchat" command over a SIP INFO message, as described in [MS-XCCOSIP].

  15. The protocol server acknowledges the message from previous step with a SIP 200 response.

  16. The protocol server replies with a "grpchat" reply over a SIP INFO message, as described in [MS-XCCOSIP].

  17. The protocol client acknowledges the message from the previous step with a SIP 200 response.

Post-conditions

  • Protocol client has an established chat session that can be used for transferring messages, notification of activity (like chat participants joined/left), invitation status, and so on.