Three-Way Calling - Cisco 7960G Administration Manual

Call Flow Scenarios for Successful Calls
Step Action
ACK—Phone A to SIP proxy
14.
server
ACK—SIP proxy server to
15.
Phone C

Three-Way Calling

Figure B-14
two RTP channels and therefore establishes a conference bridge between User A and User C. In this call
flow scenario, the end users are User A, User B, and User C. They are all using Cisco Unified IP Phone
7960G and 7940G models, which are connected using an IP network.
The call flow scenario is as follows:
1.
2.
3.
4.
5.
6.
Cisco Unified IP Phone 7960G and 7940G Administration Guide for Release 8.0 (SIP)
B-38
Description
Phone A sends a SIP ACK to the SIP proxy server. The ACK confirms that
Phone A has received the 200 OK response from Phone C.
The SIP proxy server forwards the SIP ACK to the Phone C. The ACK confirms
that Phone A has received the 200 OK response from Phone C.
illustrates successful three-way calling between Cisco SIP IP phones in which User B mixes
User A calls User B.
User B answers the call.
User B puts User A on hold.
User B calls User C.
User C answers the call.
User B takes User A off hold.
Appendix B SIP Call Flows
OL-7890-01