A-5
Cisco SIP Proxy Server Administrator Guide
Appendix A SIP Compliance
RFC 2543 and RFC 3261
415 Unsupported media Server refuses to process the request
because the format of the body is not
supported by the destination endpoint.
Yes Forwards this response.
420 Bad extension Server cannot understand the protocol
extension indicated in the Require
header.
Yes Generates and forwards this
response.
480 Temporarily
unavailable
Called party was contacted but is
temporarily unavailable.
Yes Forwards this response. If
preauthentication is enabled and
fails, generates this response.
481 Call leg/transaction
does not exist
Server ignores the request because it is
either a BYE for which there is no
matching leg ID or a CANCEL for
which there is no matching transaction.
Yes Generates and forwards this
response.
482 Loop detected Server received a request that includes
itself in the path.
483 Too many hops Server received a request that requires
more hops than allowed by the
Max-Forwards header.
484 Address incomplete Server received a request that contains
an incomplete address.
See Cisco SPS
action
Forwards this response.
485 Ambiguous Server received a request that contains
an ambiguous called-party address. It
can provide possible alternative
addresses.
486 Busy here Called party was contacted but his or
her system is unable to take additional
calls.
487 Busy here; request
cancelled
Request was terminated by a BYE or
CANCEL request.
Yes
488 Not acceptable media An error in handling the request
occurred.
See Cisco SPS
action
Table A-3 SIP Responses (continued)
SIP Response Meaning Supported? Cisco SPS Action
