Cisco 7960G Administrator's Manual page 107

Appendix B SIP Call Flows
The call flow scenario is as follows:
User A calls User B.
1.
User B answers the call.
2.
User B places User A on hold.
3.
User B calls User C.
4.
User B disconnects from User C.
5.
User B takes User A off hold.
6.
The original call continues.
7.
Figure B-5
SIP IP
Phone User A
1. INVITE B
2. 180 Ringing
3. 200 OK
4. ACK
2-way RTP channel
5. INVITE (c=IN IP4 0.0.0.0)
6. 200 OK
7. ACK
A is put on hold. The RTP channel between A and B is torn down.
14. INVITE (c=IN IP4 IP-User B)
15. 200 OK
16. ACK
A is taken off hold. The RTP channel between A and B is reestablished.
Call Hold with Consultation
IP
Phone User B
IP Network
Cisco SIP IP Phone Administrator Guide, Release 6.x and 7.x
Call Flow Scenarios for Successful Calls
SIP IP
IP
8. INVITE C
9. 180 Ringing
10. 200 OK
11. ACK
2-way RTP channel
12. BYE
13. 200 OK
B is disconnected from C.
SIP IP
Phone
User C
IP
B-11