Internet access is growing steadily in developing nations, but limited infrastructure means that at times connections can still be painfully slow. A major bottleneck for these countries is the need to force a lot of traffic through international links, which typically have relatively low bandwidth.

Technology Review

Now computer scientists in Pakistan are building a system to boost download speeds in the developing world by letting people effectively share their bandwidth. Software chops up popular pages and media files, allowing users to grab them from each other, building a grassroots Internet cache.

In developed countries, Internet service providers (ISPs) create Web caches--machines that copy and store content locally--to boost their customers' browsing speeds. When a user wants to view a popular website, the information can be pulled from the cache instead of from the computer hosting the website, which may be on the other side of the planet and busy with requests. Similar services are offered by content distribution companies such as Akamai, based in Cambridge, MA. High-traffic sites pay Akamai to host copies of their content in multiple locations, and users are automatically served up a copy of the site from the cache closest to them.

In countries like Pakistan, Internet connections are generally slow and expensive, and few ISPs offer effective caching services, limiting access to information--one reason why the United Nations has made improving Internet connectivity worldwide one of its Millennium Development Goals. None of Pakistan's small ISPs cache much data, and traffic is often routed through key Internet infrastructure in other nations.

"In Pakistan, almost all the traffic leaves the country," says Umar Saif, a computer scientist at the Lahore University of Management Sciences (LUMS). That's the case even when a Pakistani user is browsing websites hosted in his or her own country. "The packets can get routed all the way through New York and then back to Pakistan," Saif says.

So Saif's team at LUMS is developing DonateBandwidth, a system inspired by the BitTorrent peer-to-peer protocol that is popular for trading large music, film, and program files. With BitTorrent, people's computers swap small pieces of a file during download, reducing the strain placed on the original source.