Call Flow Scenarios for Successful Calls
Figure B-7
SIP IP
Phone User A
1. INVITE
2. 100 TRYING
3. 180 RINGING
4. 200 OK
5. ACK
2-way voice path
6. INVITE (c=0.0.0.0)
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
Cisco SIP IP Phone Administrator Guide
B-22
Cisco SIP IP Phone-to-Cisco SIP IP Phone Call Transfer Without Consultation Using
Bye/Also
IP Network
IP
User B presses blind transfer.
User B dials user C.
SIP IP
Phone User B
IP
Appendix B
SIP Call Flows
SIP IP
Phone User C
IP