This object represents last VOIP failue reason code of this voice client. These reason codes are taken from SIP standards. unknown - Unknown error normalFailure - Call failed for insufficient bandwidth roamFailure - SIP call failed during roaming maxLimitExceeded - Maximum SIP call permissible limit was exceeded. sipPrefCallNoBw - No bandwidth available for SIP preferred calls. badRequest - The request could not be understood due to malformed syntax. unathorized - The request requires user authentication. paymentRequired - Reserved for future. forbidden - The server understood the request, but is refusing to fulfill it. notFound - The server has definitive information that the user does not exist at the domain specified in the Request-URI. methodNotallowed - The method specified in the Request-Line is understood, but not allowed for the address identified by the Request-URI. notAcceptable - The resource identified by the request is only capable of generating response entities that have content characteristics not acceptable according to the Accept header field sent in the request. proxyAuthenticationRequired - This code is similar to 401 (Unauthorized), but indicates that the client MUST first authenticate itself with the proxy. requestTimeout - 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. conflict - This is used to indicate that the request could not be completed due to a conflict with the current state of the resource. gone - The requested resource is no longer available at the server and no forwarding address is known. lengthRequired - The server is refusing to process a request because the request entity-body is larger than the server is willing or able to process. requestEntityTooLarge - The server is refusing to process a request because the request entity-body is larger than the server is willing or able to process. requestURITooLarge - The server is refusing to service the request because the Request-URI is longer than the server is willing to interpret. unsupportedMediaType - The server is refusing to service the request because the message body of the request is in a format not supported by the server for the requested method. badExtension - The server did not understand the protocol extension specified in a Proxy-Require or Require header field. temporarilyNotAvailable - The callee's end system was contacted successfully but the callee is currently unavailable. callLegDoesNotExist - This status indicates that the UAS received a request that does not match any existing dialog or transaction. loopDetected - The server has detected a loop. tooManyHops - The server received a request that contains a Max-Forwards header field with the value zero. addressIncomplete - The server received a request with a Request-URI that was incomplete. ambiguous - The Request-URI was ambiguous. busy - The callee's end system was contacted successfully, but the callee is currently not willing or able to take additional calls at this end system. internalServerError - The server encountered an unexpected condition that prevented it from fulfilling the request. notImplemented - The server does not support the functionality required to fulfill the request. badGateway - The server, while acting as a gateway or proxy, received an invalid response from the downstream server it accessed in attempting to fulfill the request. serviceUnavailable - The server is temporarily unable to process the request due to a temporary overloading or maintenance of the server. serverTimeout - The server did not receive a timely response from an external server it accessed in attempting to process the request. versionNotSupported - The server does not support, or refuses to support, the SIP protocol version that was used in the request. busyEverywhere - The callee's end system was contacted successfully but the callee is busy and does not wish to take the call at this time. decline - The callee's machine was successfully contacted but the user explicitly does not wish to or cannot participate. doesNotExistAnywhere - The server has authoritative information that the user indicated in the Request-URI does not exist anywhere. sessionNotAcceptable - The user's agent was contacted successfully but some aspects of the session description such as the requested media, bandwidth, or addressing style were not acceptable.