Cisco Systems IP phone 7960 manual Step Action Description

Appendix B SIP Call Flows

Call Flow Scenarios for Successful Calls

Step	Action	Description
6	200 OK—Cisco SIP IP phone C	Cisco SIP IP phone C sends a SIP 200 OK response to the
	to SIP proxy server	SIP proxy server.
7	200 OK—SIP proxy server to	SIP proxy server forwards the SIP 200 OK response to
	Cisco SIP IP phone A	Cisco SIP IP phone A.
8	ACK—Cisco SIP IP phone A to	Cisco SIP IP phone A sends a SIP ACK to the SIP proxy
	SIP proxy server	server. The ACK confirms that the SIP proxy server has
		received the 200 OK response from Cisco SIP IP phone C.
9	ACK—SIP proxy server to Cisco	SIP proxy server forwards the SIP ACK to the Cisco SIP IP
	SIP IP phone C	phone C. The ACK confirms that Cisco SIP IP phone A has
		received the 200 OK response from Cisco SIP IP phone C.

Cisco SIP IP Phone-to-Cisco SIP IP Phone Network Call Forwarding (Busy)

Figure B-10 illustrates successful call forwarding between Cisco SIP IP phones in which User B has requested call forwarding from the network in the event the phone is busy. When User A calls User B, the SIP proxy server tries to place the call to Cisco SIP IP phone B and, if the line is busy, the call is transferred to Cisco SIP IP phone C. In this call flow scenario, the end users are User A, User B, and User C. They are all using Cisco SIP IP phones, which are connected via an IP network.

The call flow scenario is as follows:

1.User B requests that if their phone (Cisco SIP IP phone B) is busy the network should forward incoming calls to Cisco SIP IP phone C.

2.User A calls User B.

3.User B’s phone is busy.

4.The network transfers the call to Cisco SIP IP phone C.

	Cisco SIP IP Phone 7960 Administrator Guide
B-44	78-10497-02