equalitie
Investigate PCP (Port Control Protocol) and consider supporting it
PCP seems to be an alternative to UPnP which also allows to setup port forwarding and possibly firewall pinholes but is supposedly more secure. Investigate it and decide whether it makes sense supporting it.
Ok, so the protocol from Apple is the NAT-PMP, which has been superseded by PCP. This link may be useful as it also contains links to some relevant RFCs but in particular the PCP RFC 6887 one
http://miniupnp.free.fr/nat-pmp.html
Wonder if this is even worth it. Now we have socket sharing between DHT and QUIC the use case for this is pretty narrow: one would have to be behind a very restrictive NAT so that our hole punching won't work and have a router that supports PCP (my impression is there is not that many of those). I'm inclined to close this and possibly reopen only if users request it?
