[jitsi-dev] STUN servers too slow

I have been using Jitsi for some time now, starting with versions 2.4
and later, without major issues. Lots of other issues though (copy&paste
not working, windows not focusing, Java not shutting down, hidden
Windows, duplicated menu items, configuration files messed up) but I

Starting a few days ago calls were no longer able to connect at all,
with "ICE failed" messages.

When the problem did not fix itself and me and a friend got tired of
using a plain old telephone, so we started experimenting.

After wasting an afternoon (installing older and newer versions,
starting the configuration from scratch, reading the source code etc.)
we finally found that the problem can be fixed by using
stun1.google.com/19302 as STUN server (we are both behind NAT).

All other servers, including jitsi-xmpp.u-strasbg.fr/3478 are too slow
and it looks as if the harvester gets discarded before the reply is in.

We tested the STUN servers with a stun server test tool, and the replies
looked OK. Are all servers but Google simply too slow for a timeout of
only 400ms?

Why is there a 400ms timeout at all? I have no problem waiting a second
or two for connection, as long as there is a connection eventually.

We are now using 2.7 nightly.