[MMUSIC] General SDP usage question

"Klatsky, Carl" <Carl_Klatsky@cable.comcast.com> Thu, 31 October 2013 21:03 UTC

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From: "Klatsky, Carl" <Carl_Klatsky@cable.comcast.com>
To: "'mmusic@ietf.org'" <mmusic@ietf.org>
Thread-Topic: General SDP usage question
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Date: Thu, 31 Oct 2013 21:03:41 +0000
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Subject: [MMUSIC] General SDP usage question
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HI MMUSICers,

I have a general SDP usage question that could not confirm from the RFCs.

Party A sends an Offer with codecs 9,0
Party B does not support codec 9, so Party B Answer is just 0
Party A sends ACK to setup the call with codec 0

Later, Party A performs a flash hook to place Party B on-hold, and Party A sends an Offer again with codecs 9,0
Party B sends a 488 Not Acceptable Here error

Question: When Party A performs the flash hook, should it have only included codec 0 since it has previous knowledge that Party B only supports codec 0?  Or is what Party A sent acceptable within the definition of this protocol?

Thanks & Regards,

Carl Klatsky