Pete,

The background is that there should be no good reason for not tunnelling TCS and MSDet into the same H.225 message. I agree that the wording ought to be improved (I heard or suggested at Monterey two or three alternatives that I consider better than the one you quote).

Regards, Chris

-----Original Message----- From: Pete Cordell [mailto:pete@TECH-KNOW-WARE.COM] Sent: 22 June 1999 9:54 To: ITU-SG16@MAILBAG.INTEL.COM Subject: Question about text in implementers guide

Dear All,

The following revised paragraph seems to have been added to H.323 v3 via the implementers guide.

Endpoint system capabilities are exchanged by transmission of the H.245 terminalCapabilitySet message. This capability message shall be the first H.245 message sent. If prior to successful completion of terminal capability exchange, any other procedure fails, (i.e. rejected, not understood, not supported) then the initiating endpoint should initiate and successfully complete terminal capability exchange before attempting any other procedure. An endpoint which receives a terminalCapabilitySet message from a peer prior to initiating capabilities exchange shall respond as required by 6.2.8.1, and should initiate and successfully complete capabilities exchange with that peer prior to initiating any other procedure.

I'm a bit confused about what it is saying. It seems to be saying that an endpoint can send a TCS and prior to receiving the Ack, send MSD (as there is really no other procedure that can fail). This is a good thing. However, it then says, that if for some reason you receive TCS before you yourself have sent one, then, I think the paragraph is saying that, you must send your own TCS, and are not allowed to do MSD until you get the TCS Ack back. This is a bad thing. But worse still there seems to be conflicting information for what is essentially a minor timing issue. Could someone kindly explain to me what the background to it is.

Thanks,

Pete

============================================= Pete Cordell pete@tech-know-ware.com =============================================