Modems across IP trunks (Mitel 3300)

[ralph]

After upgrading to ver 5 from 9 we now have issues with modems across IP trunks where they worked fine before.

Mitel put out what appears to be a related KB article where they say they have a 'work around' for release 4 SP4 & 5.
Problem is: they don't say what the work around is.   Just looking to see if anyone knows.

Here's the KB article:
   
Article ID #
12-5127-00102  Article Type
Technical Bulletin
 
Article Title
Repost: Analog Alarm Circuits, Modems, and POS terminals  Publish Date
Jul-27-2012
   

Ralph   
   
   
 

[boycey9]

Try turning compression off on the route

[ralph]

I'd do that but...
Compression isn't being used.

Ralph

[acejavelin]

Yeah... We saw this start happening at around release 7 (guessing, its been awhile)... although dial-up data has always been kind of flaky over IP, it seems in the last few years almost any analog, dial-up data device is not going to work across IP trunks EXCEPT faxing and then only if you have DSPII cards and use T.38

I have tried getting various dial-up modems, credit card machines, alarm systems (DTMF based ones work fine), water meters, time clocks, etc. to work over IP trunking and it fails 98% of the time, it fails so much that I quit trying it.

This is not unique to the Mitel, in our hosted SIP side of the business we have a rule of thumb, if it has dial-up data and not a fax then it has to stay on an analog CO copper line... a lesson learned the hard way.

[cheg]

Because modem over IP was supported under ideal network conditions and network timing, the workaround must be tailored to the specific conditions of a your network. Working closely with Mitel Technical Support will help you achieve this, to ensure a reliable solution is reached.

[ralph]

Working closely with Mitel Technical Support will help you achieve this, to ensure a reliable solution is reached.

That isn't correct.   2nd level gave me the "not supported across IP" line.   That's not the 1st time it's happened.

But, I have good news.   Found that if in system options I turn off Voice Encryption at least the faxes work reliably again.  So I haven't had to escalate it up yet.

Waiting on word from the customer regarding the credit card machines and alarm systems.   

Ralph

[acejavelin]

Hmmm... now I wonder what version Voice Encryption started in. 

[ralph]

I heard from my customer late this PM.  Credit card machines are still failing.
Maybe the lesson learned here is: don't upgrade.

Nah.  That can't be it.

Ralph