Developing Android Applications with Adobe AIR

P2P Over a Remote Network

To use networking remotely, you need an RTMFP-capable server, such as Flash Media Server.

If you do not have access to such a server, Adobe provides a beta developer key to use its Cirrus service. Sign up to instantly receive a developer key and a URL, at http://labs.adobe.com/technologies/cirrus/.

Warning

If you are behind a firewall, your network needs to be configured to allow outgoing UDP traffic. If it is set to block such traffic, your administrator needs to configure a TURN (Traversal Using Relays around NAT) proxy.

The traditional streaming model requires clients to receive all data from a centralized server cluster. Scaling is achieved by adding more servers. Figure 15-2 shows traditional streaming/communication with the Unicast model and RTMFP in Flash Player/Cirrus.

Figure 15-2. Traditional streaming/communication with the Unicast model (left) and RTMFP in Flash Player 10.1/Cirrus 2 (right)

RTMFP, now in its second generation, supports application-level multicast. Multicasting is the process of sending messages as a single transmission from one source to the group where each peer acts as a relay to dispatch the data to the next peer. It reduces the load on the server and there is no need for a streaming server.

The Cirrus service is only for clients communicating directly. It has low latency and good security. It does not support shared objects or custom ...