Cisco Systems IP phone 7960 manual Sip Ip

Appendix B SIP Call Flows

Call Flow Scenarios for Successful Calls

Figure B-6 Cisco SIP IP Phone-to-Cisco SIP IP Phone Call Waiting

SIP IP			SIP IP	SIP IP
				Phone
	IP Network	Phone User B
Phone User A				User C
IP			IP	IP

1.INVITE B

2.180 Ringing

3.200 OK

4.ACK

2-way RTP channel

7.INVITE (c=IN IP4 0.0.0.0)

8.200 OK

9.ACK

A is put on hold. The RTP channel between A and B is torn down.

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

16.200 OK

17.ACK

A is taken off hold. The RTP channel between A and B is reestablished.

18.BYE

19.200 OK

B has disconnected from A, but the call with C (on hold) remains.

5.INVITE C

6.180 Ringing

10.200 OK

11.ACK

2-way RTP channel

12.INVITE (c=IN IP4 0.0.0.0)

13.200 OK

14.ACK

C is on hold. The RTP channel between B and C is torn down.

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

21.200 OK

22. ACK

C is taken off hold. The RTP channel between B and C is reestablished.

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	Cisco SIP IP Phone 7960 Administrator Guide
B-26	78-10497-02