[h323plus] Master/Slave and SessionIDs

[Simon Horne]

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 at lists.packetizer.com
> [mailto:h323plus-bounces at lists.packetizer.com]On Behalf Of Niek Kooij
> Sent: Friday, May 16, 2008 10:50 PM
> To: h323plus at 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
>