01Jan
Client Failure Responses
- 400 Bad Request
The request could not be understood due to malformed syntax. - 401 Unauthorized
The request requires user authentication. This response is issued by UASs and registrars. - 402 Payment Required
Reserved for future use. - 403 Forbidden
The server understood the request, but is refusing to fulfill it. Sometimes (but not always) this means the call has been rejected by the receiver. - 404 Not Found
The server has definitive information that the user does not exist at the domain specified in the Request-URI. This status is also returned if the domain in the Request-URI does not match any of the domains handled by the recipient of the request. - 405 Method Not Allowed
The method specified in the Request-Line is understood, but not allowed for the address identified by the Request-URI. - 406 Not Acceptable
The resource identified by the request is only capable of generating response entities that have content characteristics but not acceptable according to the Accept header field sent in the request. - 407 Proxy Authentication Required
The request requires user authentication. This response is issued by proxys. - 408 Request Timeout
Couldn’t find the user in time. The server could not produce a response within a suitable amount of time, for example, if it could not determine the location of the user in time. The client MAY repeat the request without modifications at any later time.