Cisco 7960G Administration Manual page 121

Appendix B SIP Call Flows
Figure B-8
SIP IP
Phone User A
1. INVITE
2. 100 TRYING
3. 180 RINGING
4. 200 OK
5. ACK
2-way voice path
6. INVITE (a=sendonly)
7. 200 OK
8. ACK
9. REFER (Refer-To: C,Referred-By: B)
10. 501 NOT IMPLEMENTED
11. BYE(Also: C)
12. 200 OK
13. INVITE (Requested-By: B)
14. 100 TRYING
15. 180 RINGING
16. 200 OK
17. ACK
2-way voice path
OL-7890-01
Call Transfer Without Consultation Using Failover
IP Network
IP
User B presses blind transfer.
User B dials user C.
Cisco Unified IP Phone 7960G and 7940G Administration Guide for Release 8.0 (SIP)
Call Flow Scenarios for Successful Calls
SIP IP
Phone User B
IP
SIP IP
Phone User C
IP
B-21