220.127.116.11 Receiving an SMB_COM_OPEN_ANDX Response
The client MUST determine whether or not the server returned an extended response, as specified in section 18.104.22.168.2. It does this by checking whether or not the WordCount is equal to 0x13. If the response is not an extended response, then the client MUST process the response as specified in [MS-CIFS] section 22.214.171.124. If the response is an extended response, then the new information specified in section 126.96.36.199.2 MUST be propagated back to the calling application.