I have seen that with tbd, which opens 5198 and 5199
UDP on 127.0.0.1
for commands and chat respectively, while the default configuration has
Echolink listening on 5198 and 5199 on 0.0.0.0, so there is hope. Will
have to test further, though I was able to connect from my new proxy to
one of the conferences on the same box.
I think your best and safest bet would be to find a conference server that can use a
proxy.
A service connected via a proxy has full functionality (this is different from a relay)
and
there is really no disadvantage to having a service connected to a proxy hosted on the
same
machine. Doing this, only the elproxy program has to open sockets for 0.0.0.0:5198 and
0.0.0.0:5199
and there are no conflicts.
Of course it would still be interesting to know if a program can be listening e.g. on
44.128.0.1:5198
(UDP) while another program on the same machine is listening on 0.0.0.0:5198 and will
receive all UDP
to port 5198 except to address 44.128.0.1
Rob