Peer-to-Peer Networking Expanded for Vista

Although Windows XP service packs have significantly advanced the peer-to-peer (P2P) networking capabilities of the Windows client, virtually no applications have emerged that take advantage of them. Nevertheless, Microsoft plans to further improve P2P in Windows Vista, expanding the P2P APIs to support, among other things, multiparty mesh networks, and making P2P APIs more accessible to managed-code applications that use the Windows Communication Foundation (formerly code-named Indigo). One showcase application, called Windows Collaboration, is a successor to Net Meeting and is shipping in the latest Vista preview release.

However, none of Microsoft’s numerous existing P2P applications make much use of the current APIs, and the new APIs incorporate none of the technology that Microsoft purchased with Groove, raising questions about how much weight developers should put on the P2P foundation supplied by Vista itself.

Common P2P Applications

In P2P networks, computers communicate directly with each other in a “mesh” of point-to-point interconnections and do not depend on servers to provide common services, such as verifying identities or resolving names to IP addresses. P2P networks offer some advantages over server-centered ones. They can be assembled on an ad hoc basis (by gamers engaged in head-to-head online play and by passengers on airplane flights, for example) and can sometimes use network bandwidth better with algorithms that efficiently “flood” messages or files to all nodes. P2P networks also avoid the cost and complexity of deploying application servers, and in some cases provide greater redundancy and error tolerance than a design centered on a small number of vulnerable servers.