B-62
Cisco SIP IP Phone Administrator Guide
Appendix B SIP Call Flows
Call Flow Scenarios for Failed Calls
8.
200 OK—Emergency proxy to
Cisco SIP IP phone (User A)
Emergency proxy sends a SIP 200 OK response to User A. The 200 OK response
notifies User A that the connection has been made.
9.
ACK—Cisco SIP IP phone
(User A) to emergency proxy
User A acknowledges the emergency proxy’s Connect message.
10.
ACK—Emergency proxy to
Cisco SIP IP phone (User B)
Emergency proxy acknowledges User B’s Connect message.
11.
BYE—Cisco SIP IP phone
(User A) to emergency proxy
User A terminates the call session and sends a SIP BYE request to the emergency
proxy. The BYE request indicates that User A wants to release the call.
12.
BYE—Emergency proxy to
Cisco SIP IP phone (User B)
Emergency proxy terminates the call session and sends a SIP BYE request to
User B. The BYE request indicates that the emergency proxy wants to release the
call.
13.
200 OK—Cisco SIP IP phone
(User B) to emergency proxy
User B sends a SIP 200 OK response to the emergency proxy. The 200 OK
response notifies the emergency proxy that User B has received the BYE request.
14.
200 OK—Emergency proxy to
Cisco SIP IP phone (User A)
Emergency proxy sends a SIP 200 OK response to User A. The 200 OK response
notifies User A that the emergency proxy has received the BYE request.
Step
Action
Description