nanog mailing list archives

Re: Can P2P applications learn to play fair on networks?


From: Adrian Chadd <adrian () creative net au>
Date: Mon, 22 Oct 2007 20:27:30 +0800


On Tue, Oct 23, 2007, Perry Lorier wrote:

Would having a way to proxy p2p downloads via an ISP proxy be used by 
ISPs and not abused as an additional way to shutdown and limit p2p 
usage?  If so how would clients discover these proxies or should they be 
manually configured?

http://www.azureuswiki.com/index.php/ProxySupport

http://www.azureuswiki.com/index.php/JPC

Although JPC is now marked "Discontinued due to lack of ISP support."
I guess noone wanted to buy their boxes.

Would anyone like to see open source JPC-aware P2P caches to build
actual meshes inside and between ISPs? Are people even thinking its
a good or bad idea?

Here's the real question. If an open source protocol for p2p content
routing and distribution appeared?

The last time I spoke to a few ISPs about it they claimed they didn't
want to do it due to possible legal obligations.

Would stronger topological sharing be beneficial?  If so, how do you 
suggest end users software get access to the information required to 
make these decisions in an informed manner?  Should p2p clients be 
participating in some kind of weird IGP?  Should they participate in 

[snip]

As you noted, topological information isn't enough; you need to know
about the TE stuff - link capacity, performance, etc. The ISP knows
about their network and its current performance much, much more than
any edge application would. Unless you're pulling tricks like Cisco OER..

If p2p clients started using multicast to stream pieces out to peers, 
would ISP's make sure that multicast worked (at least within their 
AS?).  Would this save enough bandwidth for ISP's to care?  Can enough 
ISP's make use of multicast or would it end up with them hauling the 
same data multiple times across their network anyway?  Are there any 
other obvious ways of getting the bits to the user without them passing 
needlessly across the ISP's network several times (often in alternating 
directions)?

ISPs properly doing multicast pushed from clients? Ahaha.

Should p2p clients set ToS/DSCP/whatever-they're-called-this-week-bits 
to state that this is bulk transfers?   Would ISP's use these sensibly 
or will they just use these hints to add additional barriers into the 
network?

People who write and the most annoying client users will do whatever
they can to maximise their throughput over all others. If this means
opening up 50 TCP connections to one host to get the top possible speed
and screw the rest of the link, they would.

It looks somewhat like GIH's graphs for multi-gige-over-LFN publication.. :)




Adrian


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