4.1 Main P2PSP characteristics

These are some of the P2PSP features:

• P2PSP is not aware of the broadcasted content, the bit-rate, the format, etc. Any type of stream can be transmitted without having to modify the protocol at all.
• At least one working implementation of P2PSP can be found in Launchpad [22]. It can be used/modified/expanded without restrictions as long as the GNU GENERAL PUBLIC LICENSE [9] guidelines are followed.
• P2PSP has a modular architecture. The number of modules used depends on the requirements of the system to be deployed.
• The most basic module is simple enough to run the peer process in systems with very low computing resources. The rest of modules add functionality to the protocol, such as connectivity across NATs, parallel streaming, data integrity and information privacy.
• If native IP multicast is available (even locally, as it happens in most of the local area networks), the P2PSP can use it.
• The P2PSP facilitates the use of error concealment techniques in the received stream because lost packets are spreaded along the time.
• Peers can be hosted in private networks, even if they are placed behind symmetric NATs.
• The protocol is fully compatible with multiresolution and bandwidth-adaptive streaming services. Simulcast [?], scalable video coding [?] and multiple description video coding based solutions [?] are possible.
• P2PSP has been conceived for P2P real-time streaming services but it can be used to deploy hybrid C/S-P2PSP systems.