Cisco SIP IP Phone - Page 153

B-43
Cisco SIP IP Phone Administrator Guide
Appendix B SIP Call Flows
Call Flow Scenarios for Successful Calls
Figure B-13 Cisco SIP IP Phone-to Cisco SIP IP Phone 3-Way Calling
4. ACK
9. 180 Ringing
10. 200 OK
11. ACK
8. INVITE C (Call-ID=2)
2-way RTP channel 1 between Users A and B established
5. INVITE (Call-ID=1, c=IN IP40.0.0.0)
1. INVITE B (Call-ID=1)
3. 200 OK
2. 180 Ringing
6. 200 OK
12. INVITE A (Call-ID=1, c=IN IP4 IP-User B)
13. 200 OK
7. ACK
IP Network
SIP IP
Phone
User A
SIP IP
Phone
User B
SIP IP
Phone
User C
Proxy
Server
Redirect
Server
50212
User A is taken off hold. The RTP channel 1 between User A and B
is re-established.
User A is on hold. The RTP channel 1 between User A and B is torn down.
User B mixes the RTP channels 1 and 2 and establishes a conference brigde between Users A and C
2-way RTP channel 2
between User B and
C is established
IPIPIP