Subject: H.248 - Annexes H & I

From: Pauls Markus <[email-masked]>
Date: Thu, 23 Nov 2000 10:46:28 +0100

G'day List Members,

I'm relatively new to MEGACO/H.248. Over the last couple of weeks I tried to get some basic understandings about the protocol. I also followed the extensive discussions on this list with great interest. I think, now the time has come that I would like to ask some questions too.

To start with:

In the newly approved Annexes H & I, when a reliable transport protocol is used (e.g. SCTP and MTP3B), it is recommended to provide the At-Most-Once functionality as in Annex D, but the LONG-TIMER and the TransactionResponseAck parameter shall not be used.

Looking at Annex D, it is stated that, for the purpose of the At-Most-Once functionality, the "Peer control entities are expected to keep in memory a list of the responses that they sent to recent transactions ....". Furthermore, it is stated that "the copy of the responses may be destroyed either LONG-TIMER seconds after the response is issued, or when the entity receives a confirmation that the response has been received, through the 'Response Acknowledgement parameter' [which seems to be the TransactionResponseAck parameter]".

My questions now:
*       When are the copies of the responses deleted, when there is no timer and no Response Acknowledgment parameter?
*       Or is there no list? But how to provide the At-Most-Once functionality then?

I hope someone can clarify these issues.

Best regards and many thanks for your answers in advance

        Markus Pauls

________________________________________________________
Markus Pauls

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Information and Communication Networks

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