[Asterisk-Users] Polycom phones, UNREACHABLE

[C F]

I'm having the same issues with the polycom phones, as well as with
Sipura ata's. I am also using on another natted network a sipura ata,
that I changed the settings on the sipura that might help, and it did
help, I havn't had an unreachable message since.
I'm not sure if on the second network the reason it's helped is
because of: A. the settings I changed. B. The NAT router I'm using. C.
A combination of both.
In any case, I think that the setting is what helped me. The setting
on the sipura are:
1. NAT mapping enable = Yes (the same as nat=yes in sip.conf, I believe)
2. NAT keep alive enable =yes (the same as qualify=yes in sip.conf, I believe)
On the Polycoms we have a setting:
voIpProt.SIP.keepalive.session-Timers
I'm not sure but I believe if these would be set to 1 is the same as
setting qualify=yes and the same as the sipura settings above.
As far as I understand the qualify=yes in sip.conf is meant to figure
out if the clients are too lagged by sending notify packets to them,
and if they are make them unreachable. A side effect of this is also
that it might keep the session alive, in which case if you have
problems of not being able to reach clients behind nat it will help.
Although it does help somewhat, these keep alive settings help much
more when done from the client that is behind NAT, and not from
asterisk. As is evident with my Sipura ATA that has these settings set
right.
I plan on changing the settings I outlined above on that site where I
have the problems, and I'll post back with the results.
The other things that could be wrong is that the NAT router (where I
have the problem I'm using a Westell soho router/modem combo, where I
don't have the problem I'm using a SMC soho router, the SMC has a much
better firewall than the Westell since it has a SPI engine in there,
that's why I suspect that the settings are the problem and not the
firewall) is the one not allowing the packets in after a while.