Appendix C SIP Call Flows
Call Flow Scenarios for Successful Calls
C-2
Cisco IP Phone Models 7905G and 7912G Administrator Guide (SIP)
OL-4277-01
The following types of responses are used by SIP and generated by the Cisco SIP
gateway:
• SIP 1xx—Informational responses
• SIP 2xx—Successful responses
• SIP 3xx—Redirection responses
• SIP 4xx—Client Failure responses
• SIP 5xx—Server Failure responses
• SIP 6xx—Global Failure responses
Call Flow Scenarios for Successful Calls
This section describes call flows for the following scenarios:
• Cisco IP Phone-to-SIP Server—Registration without Authentication,
page C-2
• Cisco IP Phone-to-SIP Server—Registration with Authentication, page C-4
• Cisco IP Phone-to-Cisco IP Phone—Basic SIP to SIP Call without
Authentication, page C-7
• Cisco IP Phone-to-Cisco IP Phone—Basic SIP to SIP Call with
Authentication, page C-15
Each of the call flows includes a call diagram, action descriptions table, and a
sample log file.
Cisco IP Phone-to-SIP Server—Registration without
Authentication
Figure C-1 illustrates the Cisco IP Phone registering with the SIP server where
authentication is not required for registration. Table C-1 describes these actions
in detail. Table C-2 shows the log of these actions.
The call flow is as follows:
1. Cisco IP Phone requests registration.
2. Registration is completed.
