Cisco Systems IP phone 7960 manual PBX a GW1

Appendix B SIP Call Flows

Call Flow Scenarios for Successful Calls

Figure B-3 Gateway-to-Cisco SIP IP Phone Call—Successful Call Setup and Call Transfer

			SIP IP Phone
			User B
PBX A	GW1	IP Network	IP	GW2	PBX B	User C
User A
1. Setup	2. INVITE
3. Call Proceeding
	4. 100 Trying
6. Alerting	5. 180 Ringing
	7. 200 OK
8. Connect
9. Connect ACK
	10. ACK
2-way voice path	2-way RTP channel
	11. BYE (Also: C)
	12. 200 OK
	13. INVITE (Requested-By: B)			14. Setup
	15. 100 Trying			16. Call
				Proceeding
	18. 180 Ringing			17. Alerting
19. Alerting
				20. Connect
	21. 200 OK
22. Connect
23. Connect ACK				25. Connect
	24. ACK
				ACK
				2-way voice
2-way voice path	2-way RTP channel			path		41729

Cisco SIP IP Phone 7960 Administrator Guide

B-12 78-10497-02