Hi: In today P2PSIP WG meeting, Eric showed his concerns about the difference between relay peer and turn server(peer). Let me give some explanations here.
As mentioned in the relay draft, the relay peer forwards the response from the destination peer towards the sending peer. Turn server(peer) works in the similar way. But the only difference is: if the client A of turn server B wants to accept message from peer C, client A should set permission in turn server B for peer C before the the message is sent by peer C. Otherwise, it would be dropped silently. In P2PSIP request/response transaction, before a peer sends a request, it does not know which peer is the destination peer exactly beforehand. It depends on the overlay topology. And the destination peer also changes according to the overlay topology. It is impossible for the sending peer to set the permission for the destination peer in turn server case. So if turn server is used instead of relay peer, the response will be filtered and dis carded. On the other hand, for a peer, there might be several relay peers. The relay peer is on per-transaction basis. That means that the peer can use different relay peer in different transactions. So the peer has no strong reliance on the stablility of the relay peer. If a relay peer failed, it may only influence one. Other relay peer can be used in the next transactions. Any comments are appreciated. Regards Jiang XingFeng _______________________________________________ P2PSIP mailing list [email protected] https://www.ietf.org/mailman/listinfo/p2psip
