[zerox7felf]

> So, to traverse these multiple stateful firewalls, we need to share some information to get underway: the peers have to know in advance the ip:port their counterpart is using. > [...] To move beyond that, we built a coordination server to keep the ip:port information synchronized

This is where I wish SIP lived up to its name (Session Initiation Protocol, i.e. any session, such as a VPN one...) and wasn't such a complicated mess making it not worth the hassle. I mean it was made to be the communication side-channel used for establishing p2p rtp streams.

[Muromec]

Yeah, sip is doing so many things that its scary to load all them in your head at the same time.

Its like http, but its also statefull, bidirectional, federated and works over udp too.

Just looking at the amount of stuff (tls over udp included) baresip implements to barely sip. And it isnt even bloated, the stuff has to be there.

[rixed]

> Its like http

and for the same reason: both were initialy designed to be simple...