Re: [tsvwg] Network congestion, dynamic lossless compression?

Emmanuel Lochin <emmanuel.lochin@isae-supaero.fr> Sun, 04 August 2019 07:13 UTC

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From: Emmanuel Lochin <emmanuel.lochin@isae-supaero.fr>
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Subject: Re: [tsvwg] Network congestion, dynamic lossless compression?
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Dear David, all,

Le 03/08/2019 à 21:02, David G. Pickett a écrit :
> Already compressed: You may not have noticed that zip detects not 
> compressible parts and just copies them into the archive. Similarly, a 
> packet stream compressor could send such blocks on verbatim in the 
> stream, or leave the packets alone entirely.  There is a slight 
> overhead for headers on no-compression data, so the protocol would 
> need a threshold for deciding which path a packet takes.  Backlogs 
> give the node time to detect such and make decisions.  You still get 
> the potential for combining smaller packets into larger ones, gaining 
> a reduction of overhead in many media with larger local link MTU and 
> inter-packet lost media use.  There still needs to be a packet discard 
> mechanism when the compressed flow falls too far behind.  What it 
> gives us is a softer saturation.  And lost packets are not free, as 
> the overhead of retransmission is a cost, as well as the pause in 
> transmission hurting both latency and bandwidth.
What kind of gain factor do you target? The idea is interesting but 
considering that Internet traffic is mostly compressed (huge video part 
for instance), BREACH attack, latency resulting of on the fly 
compression, I reckon you won't gain anything, may be epsilon?

EL

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Emmanuel LOCHIN
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