B-14
Cisco SIP IP Phone Administrator Guide
Appendix B SIP Call Flows
Call Flow Scenarios for Successful Calls
Figure B-5
Cisco SIP IP Phone-to-Cisco SIP IP Phone Call Waiting
IP
IP
IP
2. 180 Ringing
3. 200 OK
2-way RTP channel
A is put on hold. The RTP channel between A and B is torn down.
B has disconnected from A, but the call with C (on hold) remains.
4. ACK
C is taken off hold. The RTP
channel between B and C is
reestablished.
2-way RTP channel
C is on hold. The RTP channel
between B and C is torn down.
A is taken off hold. The RTP channel between A and B is reestablished.
7. INVITE (c=IN IP4 0.0.0.0)
8. 200 OK
9. ACK
15. INVITE (c=IN IP4 IP-User B)
16. 200 OK
17. ACK
18. BYE
19. 200 OK
1. INVITE B
11. ACK
13. 200 OK
10. 200 OK
21. 200 OK
20. INVITE (c=IN IP4 IP-User B)
22. ACK
14. ACK
12. INVITE (c=IN IP4 0.0.0.0)
5. INVITE C
6. 180 Ringing
IP Network
SIP IP
Phone User A
SIP IP
Phone User B
SIP IP
Phone
User C
41467