Subject: Re: [AVT] IESG comments on draft-ietf-avr-rtp-retransmission-11.txt - Issue 5: multiple retransmission requests

From: "W. Mark Townsley" <[email-masked]>
Date: Wed, 22 Jun 2005 10:38:05 -0400

Jose Rey wrote:

> Mark,
> 
> "Page 13, Section 7, Congestion control.
> 
> 
>>   In addition, the sender MAY selectively retransmit only the 
>>   packets that it deems important and ignore NACK messages for other 
>>   packets in order to limit the bitrate.  
> 
> 
> I think this could end up creating a situation where one side asks for a
> packet repeatedly (multiple retransmission NACKs), and the other side
> ignores the request repeatedly (not sending due to selective
> retransmission)? Is this considered a reasonable and expected behavior
> of the protocol?"
> 
> ==>Yes, but this is not dangerous. A client may report over a fixed
> window of SN values, in other words, carry fixed number of RTCP NACK
> reports as the RTCP packet size allows.  Although this
> client-requesting-server-ignoring can happen a couple of times it
> doesn't add any danger or overhead since the NACK window simply "moves
> on"

So, I assume the max receive window size is defined to be smaller than the min 
number of retransmissions?

- Mark

> 
> Cheers,
> 
> ---------------------------------------------
> Jose Rey     mailto:[email-masked]
> P R D C G - Panasonic R&D Center Germany GmbH
> Phone/Fax: +49(0)6103766-134/166
> --------------------------------------------- 
> 
> 
> _______________________________________________
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> [email-masked]
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> 

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