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Cisco Unified IP Phone 7960G and 7940G Administration Guide for Release 8.0 (SIP)
OL-7890-01
Appendix A Compliance with RFC 3261
SIP Responses
4
xx
Response—Request Failure Responses
4
xx
Response
Supported?
Comments
400 Bad Request
Yes
The phone generates a 400 Bad Request response for
an erroneous request. For an incoming response, the
phone initiates a graceful call disconnect (during
which the caller hears a fast busy tone).
401 Unauthorized
Yes
If a 401 Unauthorized response is received, the phone
accepts the response and sends a new request that
contains the user’s authentication information in the
format of the HTTP digest as modified by RFC 3261.
402 Payment Required
Yes
The phone does not generate the 402 Payment
Required response.
403 Forbidden
Yes
If the phone receives a 403 Forbidden response, it
notifies the user of the response. This response
indicates that the SIP server has the request but will not
provide service.
404 Not Found
Yes
The phone generates this response if it is unable to
locate the callee. Upon receiving this response, the
phone notifies the user.
405 Method Not Allowed
Yes
If the phone receives a 405 Method Not Allowed
response, it notifies the user of the response.
406 Not Acceptable
Yes
The phone does not generate a 406 Not Acceptable
response. For an incoming response, the phone
initiates a graceful call disconnect (during which the
caller hears a busy or fast busy tone) before clearing
the call request.
407 Proxy Authentication
Required
Yes
If a 407 Proxy Authorization Required response is
received, the phone accepts the response and sends a
new request that contains the user’s authentication
information in the format of the HTTP digest as
modified by RFC 3261.
408 Request Timeout
Yes
For an incoming response, the phone initiates a
graceful call disconnect (during which a caller hears a
fast busy). The phone generates this response after an
INVITE Expires timeout to avoid leaving the phone in
a continuous ringing state (fail safe mechanism). This
will occur only if the phone does not receive any
messages from the network to tear down the call after
the timer expires.
409 Conflict
Yes
The 409 Conflict response indicates that the INVITE
request could not be processed because of a conflict
with the current state of the resource. If this response
is received, the user is notified.
410 Gone
Yes
The 410 Gone response indicates that a resource is no
longer available at the server and no forwarding
address is known.
