I don't fully agree with emoci, but his post refreshed my mind
Try to use different
local ports as I suggested earlier or different
remote (server) ports. Check this thread
http://forum.voxalot.com/voxalot-sup...oxy-ports.html
The idea behind this is to force your NAT device (router) to create completely different mappings for your ATAs.
This is how it looks within the router:
Code:
udp 17 170 src=my-local-ip dst=85.17.19.194 sport=5060 dport=5060 src=85.17.19.194 dst=my-external-ip sport=5060 dport=5060 [ASSURED] use=1 mark=257
Here 85.17.19.194 is the address of eu.voxalot.com, both client & server are using ports 5060/UDP (sport & dport).
STUN should not improve the situation but personally I'm always suggesting to have it enabled.
Port forwarding may help, as soon as Siemens does not support sending keepalives. Alternatively register expiration interval may be lowered to achieve the similar keepalive effect.