You probably didn’t notice that Flash Player 10 (and AIR 1.5) shipped with a new protocol for p2p (peer-to-peer) communication. The RTMFP (Real-Time Media Flow Protocol) is a new protocol that supports direct connections between two endpoints.
What is the benefit of p2p communication? This will lower the barrier to entry for people to create real-time applications in Flash Player and AIR. No more bandwidth and server management expenses. The RTMFP protocol will also be a higher quality connection since it is over UDP and not TCP like the RTMP (Real-Time Messaging Protocol) used by Flash Media Server. RTMFP will re-establish a connection if there is a brief outage and maintain a session even if the client’s IP address changes.
This new protocol could be used for a number of applications like: text chat, VoIP conversations, video chat or multi-player games/applications.
Adobe announced Stratus the week. The is a hosted rendezvous service that allows two endpoints to establish a p2p connection. Once the connection is established the service is no longer used to send the data between endpoints. Stratus is currently in beta, but is not yet available for developers to start playing with it.
You can see a few of the RTFMP details in the ActionScript 3 Language Reference (see NetConnection).