4xx 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 gateway 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.
|
411 Length Required
|
Yes
|
This response indicates that the user refuses to accept the request without a defined content length. If received, the phone resends the INVITE request if it can add a valid Content-Length header field.
|
413 Request Entity Too Large
|
Yes
|
If a retry-after header field is contained in this response, the user can attempt the call once again in the retry time provided.
|
414 Request—URL Too Long
|
Yes
|
The user is notified if this response is received.
|
415 Unsupported Media
|
Yes
|
The user is notified if this response is received.
|
420 Bad Extension
|
Yes
|
The user is notified if this response is received.
If the phone does not understand the protocol extension specified in the Require field, the 420 Bad Extension response is generated.
|
480 Temporarily Unavailable
|
Yes
|
The response is received only by the phone. The user is notified if this response is received.
|
481 Call Leg/Transaction Does Not Exist
|
Yes
|
The user is notified if this response is received.
|
482 Loop Detected
|
483 Too Many Hops
|
484 Address Incomplete
|
485 Ambiguous
|
Yes
|
If a new contact is received, the phone might reinitiate the call.
|
486 Busy Here
|
Yes
|
The 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
|
When media cannot be negotiated properly, the phone receives and generates this response.
|