hi,all experts is the following i marked by <<<>>> a error? i think it should possibly be H.245 control channe. 8.1 Secure H.245 channel operation Assuming that the connection procedures in the previous clause (Connection establishment procedures) indicate a secure mode of operation, the negotiated handshake and authentication shall occur for the <<<H.245 logical channel>>> before any other H.245 messages are exchanged. If negotiated, any exchange of certificates shall occur using any mechanism appropriate for the H-Series terminal(s). After completing the securing of the H.245 channel, the terminals use the H.245 protocol in the same manner that they would in an insecure mode. special to paul,because i am not sure this mail can get to the maillist,so i have send a copy to your address.if it is a trouble,please forgive me about that. regards, wu.y.m