Cisco 7960 - Page 120

Appendix B SIP Call Flows
Call Flow Scenarios for Successful Calls
B-12
Cisco SIP IP Phone 7960 Administrator Guide
78-10497-02
Figure B-3 Gateway-to-Cisco SIP IP Phone Call—Successful Call Setup and Call Transfer
IP
3. Call Proceeding
6. Alerting
8. Connect
9. Connect ACK
14. Setup
25. Connect
ACK
16. Call
Proceeding
17. Alerting
20. Connect
1. Setup
PBX A PBX B
User A
User
C
GW1 GW2IP Network
4. 100 Trying
13. INVITE (Requested-By: B)
11. BYE (Also: C)
15. 100 Trying
18. 180 Ringing
21. 200 OK
5. 180 Ringing
7. 200 OK
2. INVITE
2-way RTP channel2-way voice path
19. Alerting
22. Connect
23. Connect ACK
2-way voice path
2-way voice
path
2-way RTP channel
12. 200 OK
10. ACK
24. ACK
41729
SIP IP Phone
User B