[asterisk-users] ITSP's no longer supporting IAX?

[Dr. Michael J. Chudobiak]

>> The choice of router/NAT is critical though. Unlimitel recommended the
>> SnapGear 560 to me, and it eliminated all the issues I was having with
>> IAX going through my Sonicwall devices.
>>
>> Just another datapoint for you...
> Just curious.
> 
> Since IAX only uses ONE port, do you have any idea what the technical
> reason behind a specific router would be critical?

Well, with a Sonicwall TZ170, you had to enabled "Firewall > VOIP > 
Enable consistent NAT", which was not the default setting.

Then, you had to figure out that "Firewall > Advanced > Default UDP 
Connection Timeout" defaulted to 30 seconds, less than the normal 
Asterisk 60 second registration timeout.

Then, for some reason, the TZ170 would simply lose packets. A fraction 
of calls would end almost immediately after they started, with Asterisk 
reporting a "raw hangup" error and INVAL packets, suggesting that some 
IAX2 packets were being lost, mis-ordered, or mis-translated.

Anyway, the Sonicwall TZ170 was totally unreliable for IAX2 connections. 
They caused me a lot of grief. Avoid them like the plague.

The Snapgear 560 "just works", which I appreciate very much!


- Mike