[Asterisk-Users] Strange intermittent NAT problem with BT100s

[Tomas Florian]

Hello, 

I have a strange problem whenever I have 2 or more BT100s behind NAT.  I am
not able to reproduce this error reliably, but it happens every 2-5 minutes.


The general setup is that there is Asterisk server sitting at a central
location.  Some peers connect directly (206,205,201) but some (204,203,200)
connect through NAT.

This all works fine ...but it is extremely unreliable ... I get UNREACHABLE
and then OK again ... UNREACHABLE and OK again .. unpredictably.  When it's
OK I can make phone calls no problem.... of course when it goes UNREACHABLE
there is trouble.

I tried to replace one of the BT100 phones with X-Lite and that one is OK
(~40ms) rock solid - or seems to be so far.  So it seems that there is
something weird going on with BT100

My configuration of BT100 is as follows:
- firmware 1.0.5.23 (I've noticed similar problems with .16 also)
- detected NAT type is symmetric NAT
- STUN stun.xten.net (I'm using Xtens ... or do I have to use my own???)
- no outbound proxy
- register expiration = 1
- keep alive interval = 20 sec (I also tried as low as 1 sec)

My sip configuration uses:
- nat = yes
- qualify = yes (I also tried longer qualify 10000 with no luck)

This is what I get with sip show peers ... the 204 and 200 are BT100 and
sometimes one or both go UNREACHABLE for a while ... 203 is X-Lite and
didn't go UNREACHABLE yet.

206/206          (Unspecified)    D          255.255.255.255  0
Unmonitored
205/205          (Unspecified)    D          255.255.255.255  0
Unmonitored
204/204          209.x.x.125   D   N      255.255.255.255  38340    OK (40
ms)
203/203          209.x.x.125   D   N      255.255.255.255  1548     OK (38
ms)
201/201          192.168.2.112    D          255.255.255.255  5060
Unmonitored
200/200          209.x.x.125   D   N      255.255.255.255  37838
UNREACHABLE


Any ideas?  Is there some trick to get BT100 to cooperate?

Thanks,
Tomas