Subject: [AVT] Liaison from SMPTE re RFC 5109

From: Colin Perkins <[email-masked]>
Date: Mon, 21 Jul 2008 19:16:48 +0100

We've received the attached liaison statement from SMPTE regarding  
the non-backwards compatible nature of RFC 5109 FEC (which obsoletes  
RFC 2733), and the problems this is causing with SMPTE 2022-1.   
Comments are solicited (to the list, or privately to the chairs), so  
we can make a response reflecting working group consensus.

Thanks,
Colin (as co-chair)

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Audio/Video Transport Working Group
[email-masked]
https://www.ietf.org/mailman/listinfo/avt

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From: Magnus Westerlund <[email-masked]>
Date: Tue, 22 Jul 2008 10:56:19 +0200

Colin Perkins skrev:
> We've received the attached liaison statement from SMPTE regarding the 
> non-backwards compatible nature of RFC 5109 FEC (which obsoletes RFC 
> 2733), and the problems this is causing with SMPTE 2022-1.  Comments are 
> solicited (to the list, or privately to the chairs), so we can make a 
> response reflecting working group consensus.
> 

As an individual!

To my knowledge (based on memory) the so call RFC 2733 version that 
SMPTE has defined in SMPTE 2022-1 is no more compatible with RFC 2733 
than RFC 5109. SMPTE redefines which packets that got XOR, while RFC 
5109 has a different data structure to perform the XOR over. 
Independently, you need to implement the specific mechanism you are 
using. As I can't get the document now, I wonder if the signalling of 
their extension is clear enough. That is something to look into.

I would suggest that we respond that we understand their choice but 
point out the reasons why we changed what data was included and in which 
way. That is also the answer why we don't intended to take any larger 
consideration into the growing use of RFC 2733. As we find it troubling 
that the mistake in using non-generalized packet processing that RFC 
2733 resulted in is getting wide spread usage instead of the corrected one.

Cheers

Magnus Westerlund

IETF Transport Area Director & TSVWG Chair
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_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www.ietf.org/mailman/listinfo/avt