[VoIP] Strange SIP ATA Problem

[Doug Alderdice]

I've been having a problem for a couple of months now with my Asterisk 
setup at work that is confounding the you-know-what out of me and perhaps 
someone(s) on the list can offer some suggestions for solving it.

I have a 1.2-something HEAD version Asterisk with an X100 clone card and a 
Sipura 2000 ATA.  It serves primarily as an auto attendant in my office for 
a Centrex line that is extremely similar to a triple-8 phone number for a 
credit card activation line for a large multinational bank.  I got sick of 
the numerous calls.  (unimportant to problem)

This setup has worked flawlessly for over two years of continuous up 
time.  Long about sometime late in the fall, I started having problems 
calling out from phones attached to the ATA's lines.  I did move my office 
in September, but we're in the same building and network, besides which the 
* and ATA hangs off the wired ports of a LinkSys wireless router so it is 
more or less isolated from the building network at large.  Nothing changed 
in the setup in the move, everything moved with me so it's the same router 
with the same settings in the same building on the same network 
etc.  Worked fine after the move.  The problem, which I believe to be 
unrelated to the move, developed later.

On the * console the command "sip show peers" always shows the ATA as 
registered.  I attempt to make a call from the ATA and on the console 
screen with sip debug turned on it belches all sorts of "407 Proxy 
Authentication Required" errors.   If I place a call from the console to 
the ATA, it works, and then (usually) after that I can place calls from the 
ATA.  Though, there are times that I can place only one call and another 
call immediately following the first is greeted with the 407 errors.  It 
almost looks like a port opening/closing problem, except that I conducted a 
test of connecting the * and the ATA into an old 10BaseT hub, not connected 
to anything else, and I still have the same problem.  There's no smarts in 
the old hub I was using, so it's something strictly between the * box and 
the ATA.

Over the Presidents' Day holiday weekend I took the ATA home and after 
changing only the user and server info in the Sipura, it worked perfectly 
all weekend from my home * setup.  Brought it back to work and changed it 
back to the server and user settings for the work * and same problems.  I 
made no other configuration changes in the Sipura or in the * box, nor have 
I any time over the course of experiencing this problem.

Any ideas what I've got going on here?  Fortunately I don't use this old 
Centrex line much any more since they put in a new digital PBX, so it 
hasn't been a big deal.  Calls to the Centrex line are handled by the X100 
card and that has never been a problem.  Again, I use it more for an auto 
attendant to screen out those errant credit card calls, and the ATA comes 
into play only if the caller is someone who really meant to call here and 
hits the appropriate digit to transfer the call.  But, I also have it set 
up to dial out on the CNET which I like to do when things are slow, etc.

Many thanks in advance,

Doug A.