Workgroup Support Based on the Microsoft P2P Stack

Keywords: Peer-to-Peer Computing, P2P, Proxy, Collaborative Work

The paradigm of Peer to Peer (P2P) Computing and its applications have seen widespread adoption throughout distributed systems development. A number of our own projects use a P2P communications paradigm as a central component.

In cooperation with the Corporate Research division of Siemens AG in Munich we investigate software development based on the Microsoft Peer-to-Peer stack. Microsoft P2P stack is being developed for the Windows platform and integrated in post SP1 Installs of Windows XP and above operating systems. Prior to its full integration with the .NET CLR it offers a C API exposing functionality for name to address resolution, storage and distribution of information records based on network overlay graphs and grouping functionality that extends the graph functionality with security mechanisms for access control.

As a realistic sample application we are developing a Personal P2P Web-Proxy that can act in two different behavior modes:

speed up server replies and downloads
decrease consumption of external - and often expensive - bandwidth

Every personal proxy may join a collaboration group upon invitation by a group member. Members of such a collaboration group share their local cache contents in order to facilitate fast and economic access to the web. The basic proxy operation is shown in fig.1: A peer searches for an object (red triangle) in the collaboration group (1) that is not found (2), therefore the object is retrieved from the internet (3). A subsequent request by another peer (4) can then be fulfilled by the proxy application (5,6).

Fig. 1 - Basic operation of the P2P Proxy application.

In addition to the simple caching behavior the proxy concept comprises a close browser integration to:

enable one-click collection of content data for an internal resource repository
manage history state for selected WWW resources that allows every member of the group to "go back in time" to a special version of a document that was previously visited.

Funding: Siemens AG, Corporate Technology, München

Contact: Thomas Friese