D-4
Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (SIP)
OL-3410-01
AppendixD SIP Call Flows
Call Flow Scenarios for Successful Calls
FigureD-2 Cisco ATA-to-SIP Server—Registration with Authentication
TableD-3 Action Descriptions
Step Action Description
Step1 REGISTER—Cisco ATA to SIP server Cisco ATA sends a REGISTER message to the SIP server to
register the address in the To header field.
Step2 100 Trying—SIP server to Cisco ATA SIP server returns a 100 trying message, indicating that the
REGISTER request has been received.
Step3 407 Proxy authentication required— SIP server to
CiscoATA
SIP server returns a request for authentication.
Step4 REGISTER—Cisco ATA to SIP server CiscoATA attempts to register using its authentication
credential.
Step5 100 Trying—SIP server to Cisco ATA SIP server returns a 100 trying message, indicating that the
new REGISTER request has been received.
Step6 200 OK—SIP server to Cisco ATA SIP server returns a final 200 OK response, confirming that
the authentication credential has been verified and
registration is complete.
V
1. REGISTER
Cisco ATA 186 IP network SIP server
2. 100 Trying
3. 407 Proxy Authentication Required
4. REGISTER
5. 100 Trying
6. 200 OK
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