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B-5
Cisco Unified IP Phone 7960G and 7940G Administration Guide for Release 8.0 (SIP)
OL-7890-01
Appendix B SIP Call Flows
Call Flow Scenarios for Successful Calls
Figure B-2
Successful Call Setup and 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 (a=sendonly)
14. INVITE (a=sendrecv)
5. 180 Ringing
7. 200 OK
2. INVITE
2-way RTP channel
No RTP packets being sent
2-way VP
2-way voice path
2-way voice path
12. 200 OK
9. ACK
15. 200 OK
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