User Manual

Appendix

431

The following figure illustrates the scenario of a successful call. In this scenario, the two

end users are User A and User B. User A and User B are located at Yealink SIP IP

phones.

The call flow scenario is as follows:

1. User A calls User B.

2. User B answers the call.

3. User B hangs up.

User A Proxy Server User B

F1. INVITE B

F2. INVITE B

F3. 100 Trying

F9. ACK

F10. ACK

F5. 180 Ringing

2-way RTP channel established

F8. 200 OK

F7. 200 OK

F6. 180 Ringing

F4. 100 Trying

F11. BYE

F12. BYE

F13. 200 OK

F14. 200 OK

Step

Action

Description

INVITE—User A to Proxy

Server

User A sends a SIP INVITE message to a

proxy server. The INVITE request is an

invitation to User B to participate in a

call session.

In the INVITE request:

 The IP address of User B is inserted