Cisco SIP IP Phone - Page 117

B-7
Cisco SIP IP Phone Administrator Guide
Appendix B SIP Call Flows
Call Flow Scenarios for Successful Calls
3. User B places User A on hold.
4. User B takes User A off hold.
5. The call continues.
Figure B-3 Cisco SIP IP Phone-to-Cisco SIP IP Phone Simple Call Hold
IP IP
2. 180 RINGING
3. 200 OK
2-way RTP channel
4. ACK
A is taken off hold. The RTP channel between A and B is reestablished.
A is on hold. The RTP channel between A and B is torn down.
5. INVITE (c=IN IP4 0.0.0.0)
6. 200 OK
7. ACK
8. INVITE (c=IN IP4 IP-User B)
9. 200 OK
10. ACK
1. INVITE B
IP Network
SIP IP
Phone User A
SIP IP
Phone User B
41465