Network end users to pull down 2 gigabytes a day, continuously?

Joe Abley jabley at ca.afilias.info
Sun Jan 21 16:54:44 UTC 2007


On 21-Jan-2007, at 07:14, Alexander Harrowell wrote:

> Regarding your first point, it's really surprising that existing  
> P2P applications don't include topology awareness. After all, the  
> underlying TCP already has mechanisms to perceive the relative  
> nearness of a network entity - counting hops or round-trip latency.  
> Imagine a BT-like client that searches for available torrents, and  
> records the round-trip time to each host it contacts. These it  
> places in a lookup table and picks the fastest responders to  
> initiate the data transfer. Those are likely to be the closest, if  
> not in distance then topologically, and the ones with the most  
> bandwidth. Further, imagine that it caches the search -  so when  
> you next seek a file, it checks for it first on the hosts nearest  
> to it in its "routing table", stepping down progressively if it's  
> not there. It's a form of local-pref.

Remember though that the dynamics of the system need to assume that  
individual clients will be selfish, and even though it might be in  
the interests of the network as a whole to choose local peers, if you  
can get faster *throughput* (not round-trip response) from a remote  
peer, it's a necessary assumption that the peer will do so.

Protocols need to be designed such that a client is rewarded in  
faster downloads for uploading in a fashion that best benefits the  
swarm.

> The third step is for content producers to directly add their torrents
> to the ISP peers before releasing the torrent directly to the public.
> This gets "official" content pre-positioned for efficient  
> distribution,
> making it perform better (from a user's perspective) than pirated
> content.

If there was a big fast server in every ISP with a monstrous pile of  
disk which retrieved torrents automatically from a selection of  
popular RSS feeds, which kept seeding torrents for as long as there  
was interest and/or disk, and which had some rate shaping installed  
on the host such that traffic that wasn't on-net (e.g. to/from  
customers) or free (e.g. to/from peers) was rate-crippled, how far  
would that go to emulating this behaviour with existing live  
torrents? Speaking from a technical perspective only, and ignoring  
the legal minefield.

If anybody has tried this, I'd be interested to hear whether on-net  
clients actually take advantage of the local monster seed, or whether  
they persist in pulling data from elsewhere.


Joe




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