connections keep switching away from direct connection and switching back

[flub]

On slower connections we noticed we keep switching connections all the time. Even though we would expect them to stay direct. E.g. transcript from a modified iroh doctor:

Accepted connection from fltgqbqd37gta4bvy22zknq62m5xp4rucuijng7ds7up7ixl4daq
connection type changed to: relay
connection type changed to: direct
connection type changed to: mixed
connection type changed to: direct
17.978148733s: rtt: 332.081712ms
connection type changed to: mixed
connection type changed to: direct
connection type changed to: mixed
29.551192275s: rtt: 337.195327ms
connection type changed to: direct
connection type changed to: relay
connection type changed to: direct
connection type changed to: relay
Test finished after 40.893338786s: connection lost

[flub]

I suspect this is mostly because we have lossy ping/pongs:

... INFO ... iroh_net::magicsock::node_map::best_addr: 87: clearing best_addr reason=PongTimeout has_relay=true old_addr=213.143.125.104:57096

[flub]

this is a bit silly in a way, because we know there's a lot of traffic flowing around at this point. traffic which is being acked by quic in both directions. We only downgrade the connection because this pong is treated as more important somehow, and missing it forces downgrading our connection even if data is flowing over it.

We might be able to improve this by not considering the loss of a pong so important if other data is flowing as well.

[ramfox]

Agreed. It seems sort of silly to decide that a connection is dead if we are literally getting UDP packets from that addr at the same time as we timeout on a pong.

[dignifiedquire]

unfortunately still happening on main

onnection type changed to: mixed
connection type changed to: direct
connection type changed to: mixed
connection type changed to: direct
connection type changed to: mixed
connection type changed to: direct
connection type changed to: mixed
connection type changed to: direct
connection type changed to: mixed
connection type changed to: direct