5 ms·
Hole punching through routers. It's hard to generically connect two NAT'd devices directly. It's simpler to route through a central server.
by dymk 8y ago
Hole punching through routers. It's hard to generically connect two NAT'd devices directly. It's simpler to route through a central server.
- kitotik 8y agoHasn’t this been a solved problem for a while with STUN / TURN servers? The centralized server just handles the negotiation, so that the p2p clients can do their thing.
- Wowfunhappy 8y agoI don't recall this ever being a problem with Skype, and I used it quite extensively at the time. (Mumble is another matter...)
- oarsinsync 8y agoSkype's original USP was that it resolved the NAT issues that plagued SIP based VOIP implementations, exactly by performing hole punching through routers (I suspect just UDP hole punching)
- api 8y agoThis isn't that hard. It's even easier now that many people have IPv6. IPv6 still usually requires rendezvous due to stateful fireballing but it otherwise behaves like 1:1 NAT. (IPv6 is occasionally deployed with NAT, but in that case it is 1:1 NAT without port remapping which is also P2P-friendly.)