Summary

To summarize, P2P is about PCs communicating directly with each other without going through a centralized server. Every node in a P2P network needs to carry the responsibility of both a server and a client. It is quite common to find a centralized server that is similar to a central registry and helps the nodes to find other nodes. This is a lightweight server and usually does not participate in the communication between the nodes. Successful P2P implementations such as instant messaging and file sharing that include thousands to millions of peers have proved that P2P networks are quite reliable and secure. Also, you learned that building P2P solutions with WCF and peer channel is relatively simple but powerful and easy to implement, debug, and deploy, which will enable further adoption by both developers and users.

The next chapter will introduce interoperability with other SOA implementations and will cover some of the "gotchas" of using J2EE, MTOM, and WS-ReliableMessaging, among others, in a cross-platform implementation.