Cisco 7905G Administrator's Manual page 187

Appendix C SIP Call Flows
Table C-3 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 3 401 Unauthorized— SIP server to
Cisco IP Phone
Step 4 REGISTER—Cisco IP Phone to SIP server Cisco IP Phone attempts to register using its
Step 5
100 Trying—SIP server to Cisco IP Phone SIP server returns a 100 trying message,
Step 6
200 OK—SIP server to Cisco IP Phone
OL-4277-01
Figure C-2 Cisco IP Phone-to-SIP Server—Registration with Authentication
Cisco IP Phone IP network
IP
1. REGISTER
2. 100 Trying
3. 401 Unauthorized
4. REGISTER
5. 100 Trying
6. 200 OK
Cisco IP Phone Models 7905G and 7912G Administrator Guide (SIP)
Call Flow Scenarios for Successful Calls
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 request for authentication.
authentication credential.
indicating that the new REGISTER request has
been received.
SIP server returns a final 200 OK response,
confirming that the authentication credential has
been verified and registration is complete.
C-5