[Freeswitch-users] Grandstream GXP2000 living-dead registrations - NAT config problem???

[Alex Lake]

Got a strange problem that has only begun to manifest itself since we 
started using a host running FreeSWITCH 1.2.24.
We were previously using a host running 1.2.13. Both hosts are hosted at 
Hetzner.

I'm not 100% sure that the relevant parts of configuration haven't 
changed, although I don't think they have.

The phones are on a NATted LAN connected via ADSL to the Internet.

The problem is that, despite showing up as registered (and continuing to 
re-register), the phones can get into a state where they don't respond 
to inbound INVITEs.

Other brands of phone (eg. Linksys and Yealink) appear NOT to suffer 
from this problem.

The thing that baffles me is that this appears to be repeatable, but 
differs between the hosts.

What parts of FS config should I be looking at for differences?