Cisco Systems IP phone 7960 manual IP Network SIP IP Phone

Appendix B SIP Call Flows

Call Flow Scenarios for Successful Calls

Figure B-2 Gateway-to-Cisco SIP IP Phone Call—Successful Call Setup and Call Hold

User A PBX A	GW1	IP Network	SIP IP Phone
			User B
			IP

1. Setup

3. Call Proceeding

6. Alerting

8. Connect

10.Connect ACK 2-way voice path

2-way voice path

2.INVITE

4.100 Trying

5.180 Ringing

7.200 OK

9.ACK

2-way RTP channel

11.INVITE (c=IN IP4 0.0.0.0)

12.200 OK

13.ACK

No RTP packets being sent

14.INVITE (c=IN IP4 IP-User B)

15.200 OK

16.ACK

2-way VP

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	Cisco SIP IP Phone 7960 Administrator Guide
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