Cisco 7960 - Page 116

Appendix B SIP Call Flows
Call Flow Scenarios for Successful Calls
B-8
Cisco SIP IP Phone 7960 Administrator Guide
78-10497-02
Figure B-2 Gateway-to-Cisco SIP IP Phone Call—Successful Call Setup and Call Hold
IP
SIP IP Phone
User B
3. Call Proceeding
6. Alerting
8. Connect
10. Connect ACK
1. Setup
PBX A
User A
GW1 IP Network
4. 100 Trying
13. ACK
16. ACK
11. INVITE (c=IN IP4 0.0.0.0)
14. INVITE (c=IN IP4 IP-User B)
5. 180 Ringing
7. 200 OK
2. INVITE
2-way RTP channel
No RTP packets being sent
2-way VP2-way voice path
2-way voice path
12. 200 OK
9. ACK
15. 200 OK
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