Typically SessionID 1 to 3 are reserved for Audio,Video and Data. To me data means T.120. Unlike H.239 which clearly states the session ID must not be 1,2 or 3 the H.224 specification does not state whether it can use 3 (for data) or must use a higher number. This is clearly a grey area however if you offer a session ID of 4 then the tandberg device should honor that request with the same session ID and not 3. To my way of thinking this is a bug in tandberg equipment. If you are not going to use T.120 then changing the default H.224 session id to 3 should not affect anything too much.
Simon
-----Original Message----- From: h323plus-bounces@lists.packetizer.com [mailto:h323plus-bounces@lists.packetizer.com]On Behalf Of Niek Kooij Sent: Friday, May 16, 2008 10:50 PM To: h323plus@lists.packetizer.com Subject: [h323plus] Master/Slave and SessionIDs
Hi,
I am trying to get the h224/h281 data channel to work with Tandberg equipment and ran into some problems. It turns out this has to do with sessionId's. The current implementation lets the connection/endpoint create an h281handler which will handle both in- and outgoing h224 RTP. The problem is that my H323Endpoint will usually begin with opening the logical channel and assigns DefaultH224SessionID = 4 as sessionID. Later on the Tandberg endpoint wants to open a channel but then with sessionId 3! This results in the construction of a new RTP_Session which will never be used (cause the h281handler is allready constructed and has its RTP_Session set). Can anybody tell me what the "right" way would be to solve this problem? Should the incoming and outgoing h224 channels have the same sessionID? My current solution is to change DefaultH224SessionID to 3 but this will probably result into problems when more data channels need to be openend...
Thanks,
Niek