[tor-talk] IDEA: Compress traffic at exit

[Sebastian G. <bastik.tor>]

Am 20.01.2012 21:29, schrieb Andrew Lewman:
>> Overview:
>>
>>    This is about compressing traffic at the exit, where it's passed
>> from outside the network through other relays to the client where it
>>    gets decompressed.
> 
> And what decompresses the traffic at the destination site?

Just for fun. Tor would do both, compress and decompress. Well it's
pointless.

> Lack of bandwidth isn't so much the problem. Lack of tcp sockets and cpu
> power for onionskins at the relays is the problem. The higher bandwidth
> the relay, the worse these two problems become.

Too bad. (for the network)

>>    The relays (exit or not) have certain bandwidth limitations which
>> may could be circumvented by compressing the traffic they have to
>> handle, which would mean that they could handle more users.
> 
> Exit relays are already overloaded, adding compression overhead will
> not make this better. 

Sure when CPU is critical, more CPU cycles for other stuff hurt the exit.

> Lots of traffic on the Internet is already compressed between the
> client and server. What tor does in the middle is irrelevant. See the
> SPDY proposal,
> https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/ideas/xxx-using-spdy.txt

I'll read it. Thanks.

> Generally, the tor relays do not want to touch nor modify user traffic
> in any way. Once we can detect "compress or not", it's a quick slide
> down a slippery slope to "censor or not". See
> https://trac.torproject.org/projects/tor/wiki/doc/TorFAQ#YoushouldchangeTortopreventusersfrompostingcertaincontent.
> 

The idea, don't know if the .txt went through (don't waste time with
reading it), contained that this would be done blindly, every traffic or
based on port, no data analysis.

I didn't thought compression would be considered as bad because it would
alter the traffic.

Thank you for explaining.

Regards,
bastik_tor