Cisco 7905G Administrator's Manual page 185

Appendix C SIP Call Flows
Cisco IP Phone
Table C-1 Action Descriptions
Step Action
Step 1
REGISTER—Cisco IP Phone to SIP server Cisco IP Phone sends a REGISTER message to
Step 2 100 Trying—SIP Server to Cisco IP Phone SIP server returns a 100 Trying message,
Step 3
200 OK—SIP server to Cisco IP Phone
OL-4277-01
Figure C-1 Cisco IP Phone-to-SIP Server—Registration without
Authentication
IP
1. REGISTER
2. 100 Trying
3. 200 OK
Cisco IP Phone Models 7905G and 7912G Administrator Guide (SIP)
IP network SIP server
Description
the SIP server to register the address in the To
header field.
indicating that the REGISTER request has been
received.
SIP server returns a final 200 OK response,
confirming that registration is complete.
Call Flow Scenarios for Successful Calls
C-3