although OP's issue now fixed, I would like to comment on siproxd and
it's "features"
siproxd has a bug whereby it doesn't bind properly to interfaces so that
if you have a multi-homed firewall (e.g. I have a WAN, a cabled LAN and
a wireless LAN all separate), then clients on one interface will break.
In my case clients on one lan worked, the other didn't, and I couldn't
make a siproxd config that resolved the problem. I can't remember
exactly what was broken, as I found and worked-round the problem a while
back, but it was something to do with siproxd responding with the wrong
IP address.
the only solution I found was have multiple instances of siproxd, each
bound to a different interface AND PORT - so that SIP and RTP ranges had
to be different.
the way I did this on linux was to have /etc/siproxd.eth0.conf,
siproxd.wlan0.conf etc and tweak the startup script.
you can then have different networks & interfaces with different
instances of siproxd running and it will work happily - the voip clients
on each network need different configg of course.
hopefully this will prevent someone a few headaches.
Paul