Like P2P, the P4P protocol breaks files up into smaller packets, sends those around the Internet and then reassembles them at a destination, but P4P tracks the most efficient point in the networks from which to swap those files. This involves the ISPs handing over information about their network topology and knowing where a file swapper sits on the network. P4P makes it possible to know these things without exposing the data to either side. In tests with Verizon, Pando showed that by using P4P it could increase delivery speeds by up to 235 percent on U.S. cable networks and reduce intra-network traffic by 34 percent.

Il paper del progetto è liberamente scaricabile qui.
Secondo GigaOM comunque, queste soluzioni non costituirebbero un’alternativa alla messa a disposizione di maggiore banda da parte degli ISP.

DonateBandwidth works in much the same way but lets people share more than just large files. When users try to access a website or download a file, a DonateBandwidth program running on their machine checks first with the peer-to-peer cache to see if the data is stored there. If so, it starts downloading chunks of the file from peers running the same software, while also getting parts of the file through the usual Internet connection. The software could allow people in countries that have better Internet connections to donate their bandwidth to users in the developing world.

DonateBandwidth also manipulates an ISP’s cache. “Say a person with a dial-up connection wants to download a file,” Saif says. “When running DonateBandwidth, their computer starts downloading part of a file, while also sending a request for other DonateBandwidth users who have access through the same ISP, and whose computers have spare bandwidth, to trigger them to start downloading other parts of the same file.” The file is then loaded into the ISP’s cache, so it can be downloaded more quickly.

Il progetto è ancora in fase embrionale, tuttavia un primo prototipo basato su Squid, popolare cache proxy open source, ha mostrato come i vantaggi possano essere rilevanti soprattutto per chi ha una connessione lenta.