A-6
Cisco SIP IP Phone Administrator Guide
Appendix A SIP Compliance with RFC 3261 Information
SIP Responses
5
xx
Response—Server Failure Responses
480 Temporarily
Unavailable
See comments
This response is received only by the phone in this
release. The user is notified if this response is
received.
If this response is received, the user is notified that
the callee is temporarily unavailable (perhaps not
logged on), and any retry information is displayed.
481 Call
Leg/Transaction
Does Not Exist
See comments
This response is received only by the phone in this
release. The user is notified if this response is
received.
482 Loop Detected
483 Too Many
Hops
484 Address
Incomplete
485 Ambiguous
See comments
This response is received only by the phone in this
release.
If a new contact is received, the phone might
reinitiate the call.
486 Busy Here
Yes
The Cisco SIP IP phone generates this response if
the called party is off-hook and the call cannot be
presented as a call-waiting call. Upon receiving this
response, the phone notifies the user and generates
a busy tone.
487 Request
Canceled
Yes
This response indicates that the initial request is
terminated with a BYE or CANCEL request.
488 Not
Acceptable
Yes
The Cisco SIP IP phone receives and generates this
response.
5
xx
Response
Comments
500 Internal Server Error
The Cisco SIP IP phone does not generate these 5xx responses. For
an incoming response, the SIP IP phone initiates a graceful call
disconnect.
501 Not Implemented
502 Bad Gateway
503 Service Unavailable
504 Gateway Timeout
505 Version Not Supported
4
xx
Response
Supported?
Comments