Re: [AVTCORE] I-D Action: draft-ietf-avtcore-multi-party-rtt-mix-08.txt

James Hamlin <> Wed, 02 September 2020 10:39 UTC

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From: James Hamlin <>
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Thread-Topic: Re: [AVTCORE] I-D Action: draft-ietf-avtcore-multi-party-rtt-mix-08.txt
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Date: Wed, 2 Sep 2020 10:39:15 +0000
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Subject: Re: [AVTCORE] I-D Action: draft-ietf-avtcore-multi-party-rtt-mix-08.txt
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I think the compromise in V08 is a good one; we have considered quite a few options, and allowing just one sender per packet, with a fixed limit of 1 on the CC field is the only solution that can be achieved with only a small change to RFC4103. We have to acknowledge that SSRC switching time increases as the level of redundancy increases. It also increases with more participants typing at once but people typing over one another is generally the smaller part of the conversation. These two caveats have previously been acknowledged.

Because redundant generations from one SSRC have to be cleared before another SSRC can be sent, recovery of redundant data is fairly simple. But working out which SSRC has missing text, is more difficult. The current text has a clear example where it is possible to verify that nothing is missing but it would be useful to have a defined algorithm so that implementations don't get that wrong. That said, there are a lot of cases to consider, and some error cases where the sender has not followed the rules. Perhaps we just accept that implementers must work this out for themselves.

Best regards



[X]James Hamlin
Purple, a Division of ZP Better Together, LLC

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