[MMUSIC] Fixing draft-holmberg-mmusic-sdp-dtls-00

Martin Thomson <martin.thomson@gmail.com> Wed, 17 June 2015 18:10 UTC

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Date: Wed, 17 Jun 2015 11:10:08 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
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Subject: [MMUSIC] Fixing draft-holmberg-mmusic-sdp-dtls-00
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Some of the statements here are backwards.  For example,

   If an endpoint changes the local transport parameters associated with
   a DTLS association, the endpoint MUST create a new DTLS association.

I think that this document can be reduced to a series of conditionals:

If you change the endpoint that is participating (because forking, or
for any other reason), then you need a new DTLS association.
Otherwise, how will that new endpoint know what keys to use.

If you change the certificate you intend to use, then you need a new
DTLS association.  Otherwise, you don't get to send the new

If you change the DTLS roles, then you need a new DTLS association.
Otherwise, it doesn't happen.

If you request a new DTLS association, then you need a new transport.
Otherwise, demux issues.

An ICE restart is not sufficient a change to constitute a new
transport.  You need entirely new IP+port pairs.