AppendixA SIP Compliance with RFC-2543 Information
SIP Header Fields
A-10
Cisco SIP IP Phone 7960 Administrator Guide
78-10497-02

5xx Response—Server Failure Responses

6xx Response—Global Responses

SIP Header Fields
5xx Response Comments
500 Internal Server Error
For an incoming response, the Cisco SIP IP
phone sends a new request if an additional
contact address is present. If an additional
contact address is not present, the gateway
initiates a graceful call disconnect.
501 Not Implemented
502 Bad Gateway
503 Service Unavailable
504 Gateway Timeout
505 Version Not Supported
6xx Response Comments
600 Busy Everywhere The Cisco SIP IP phone does not generate
these 6xx responses. For an incoming
response, the gateway initiates a graceful call
disconnect.
603 Decline
604 Does Not Exist Anywhere
606 Not Acceptable
Header Field Supported?
Accept Yes
Accept-Encoding Yes
Accept-Language Yes
Allow Yes
Also Yes