Yealink SIP-T38G

Administrator’s Guide for SIP-T3xG IP Phones
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The following figure illustrates a successful call setup and call hold. In this scenario, the
two end users are User A and User B. User A and User B are located at the 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 A puts User B on hold.
User A Proxy Server User B
F1. INVITE B
F2. INVITE B
F7. ACK
F8. ACK
F3. 180 Ringing
F6. 200 OK
F5. 200 OK
F4. 180 Ringing
F12. 200 OK
F9. INVITE B (sendonly)
F10. INVITE B (sendonly)
F11. 200 OK
F14. ACK
F13. ACK
No RTP packets being sent
2-way RTP channel established