Cisco 7960G Administrator's Manual page 102

Call Flow Scenarios for Successful Calls
Step Action
14. INVITE—Cisco SIP IP phone to Gateway 1
15. 200 OK—Gateway 1 to Cisco SIP IP phone
16. ACK—Cisco SIP IP phone to Gateway 1
Call to a Gateway Acting As an Emergency Proxy from a Cisco SIP IP Phone
Figure B-3
proxy.
Figure B-3
SIP IP Phone
Cisco SIP IP Phone Administrator Guide, Release 6.x and 7.x
B-6
illustrates a successful call from a Cisco SIP IP phone to a gateway acting as an emergency
Successful Call from Cisco SIP IP Phone to SIP Gateway (Emergency Proxy)
Proxy
User A
IP
1. INVITE (Matches dial template for emergency route)
4. 100 Trying
6. 180 Ringing
8. 200 OK
9. ACK
11. BYE
14. 200 OK
Description
User B takes User A off hold. The phone sends a SIP INVITE request
to Gateway 1.
Gateway 1 sends a SIP 200 OK response to the phone. The response
notifies the phone that the INVITE was successfully processed.
The phone sends a SIP ACK to Gateway 1. The ACK confirms that
the phone has received the 200 OK response. The call session is now
active.
GW
2. Setup
3. Call Proceeding
5. Alerting
7. Connect
10. Connect ACK
2-way voice path
12. Disconnect
13. Release
15. Release Complete
Appendix B SIP Call Flows
User B
PBX