The P4P working group demo’d their work Friday at the Distributed Computing Industry Association show in New York. Not only did they show 2-3x faster downloads, but they also cut the average number of inter-metro hops – the expensive kind – from over 5 to less than 1. Cool.
The P4PWG idea is that if P2P is both cheaper for ISPs and faster for users we will all have a happier Internet. Folks from the Yale CompSci department – Haiyong Xie, Y. Richard Yang and Avi Silberschatz – along with Verizon and Pando Networks, cooperated on the demo.
The P4PWG includes AT&T, Verizon, Pando, BitTorrent, Cisco and LimeWire among others. The cable companies are there as observers. The P4P work is an open standard with the hope that all ISPs and P2P networks will endorse it.
How does it work?
The tech papers aren’t available yet on the web, but this is what I’ve pieced together from an afternoon’s websurfing. Update: Wide-awake reader Paul found this P4P Overview on Ars Technica. Thanks Paul! End update.
P2P is network oblivious. When you start downloading streams they might be from anywhere, regardless of network cost. The problem is that big routers are costly and smaller routers are much cheaper, not to mention undersea fiber.
What P4P is inject some knowledge into the P2P network so peering decisions are made more intelligently. It looks like a network version of locality of reference.
There are at least 2 ways to deliver network awareness to peers. Here’s one of them.
A peer-tracker (pTracker) and an Internet tracker (iTracker) are added to the P2P network. A peer requests peering information of the pTracker, which has knowledge of local (metro area) and recent non-local resources. The pTracker sends back an edited server list and the peer goes its merry way.
If the resources aren’t local and the pTracker doesn’t know the network topology, it pings the iTracker, which returns high-level peering suggestions. If locality of reference works as well in cyberspace as it does with other data the pTracker won’t be querying the iTracker very often.
It is expected that the pTracker will be maintained by the P2P network, while the iTracker could be maintained by the ISP, network or a trusted 3rd party. This should preserve help P2P user privacy, although the *Tracker names certainly won’t reduce user paranoia.
Guys, how about something less Big Brotherish? PeerServer and RoutServer? Just a thought.
The StorageMojo take
As file sizes continue their secular trend upward the need for P2P will continue to grow. By aligning ISP, telco and user needs for faster and more efficient P2P the P4PWG has pulled off a win/win/win situation.
A less obvious benefit of this work is on VoIP networks, which are also P2P. It doesn’t take much to degrade VoIP quality. To the extent that it enables improvement in P2P network node selection, the P4P project will benefit the rapidly growing population of VoIP users as well.
Kudos to the P4PWG and especially the Yale team.
Comments welcome, of course. Images courtesy of the P4PWG.