atcomsystems.ca/forum Forums TDM Business Telephone Systems Mitel Telephones & Systems ASU Fax Problems on ICP 3300

We have a 3300 8.0 UR4 with 2 ASU 16 port devices attached. We've had various fax machines and speaker phones on these ASUs for 3 years and have never heard of a problem. Recently people have been getting communication errors and sometimes faxes get cut off on 3 different fax machines on 2 different ASUs. I've tried different fax machines and I've tried different ports and it made no difference. Fax machines with POTS lines haven't had any trouble so I swapped a POTS line with an ASU line to see if the trouble would follow. To my surprise the trouble had cleared when the lines were swapped, but started in again when they were put back to the original position. Unfortunately leaving them swapped isn't an option. When ASU line was in a Brother fax machine it was having issues, when plugged into a large Sharp printer/copier with a fax board installed it worked fine. Two of the fax machines having troubles and the POTS line fax machine are approximately 400' (rough guess) from the ASUs. The other fax having trouble on an ASU line is only about 50' away from the ASU.
It seems odd that both ASUs would start having issues at the same time. I have also tried resetting both units and took steps to eliminate RF. Nothing had really changed in any of the enironments before the trouble started. Also, nobody has reported issues using the speakerphones in conference rooms which are attached to the ASUs.
Has anyone ever heard of fax machines having troubles with ASUs and if so, are some machines more susceptible than others?

First of all, have there been ANY changes in your trunkage. New lec maybe. New ld service. Started using voip or T1?

What Lightninghorse said...
Also, is it incoming, outgoing or both?
If only outgoing is it LD, local, or both?
Are you on PRI, T-1, or analog trunks?
Do you use account codes (carrier) for LD?

Dave

Now that you mention it, we did sign some new contracts for our PRI last spring and long distance changed from SBC to AT&T in August as part of the same deal. It all was pretty seamless and the billing is pretty much the same so I forgot about it.
It sounds like you guys are leaning towards the phone company and not the ASUs. Is this a common occurance that faxing becomes an issue when making changes like this? I haven't heard of any voice problems.
It is happening with both local and LD, both incoming and outgoing.
Any advice is greatly appreciated.

Hmmm...
If it were me I think I'd take a very serious look at the PRI setup.
Based on the fact that it is any type of call.
Get an exact description of the PRI from the supplier:
C.O. switch type
NI1 or NI2
Etc.

Wouldn't hurt to upgrade the 3300 if that proves OK.

Dave

I have had a few problems with new circuits installed, If it is a " flex " type circuit (voice and data on the same circuit) the carrier needs to identify the Fax/Modem DID's so they can release the compression on these calls.

You should also notice clocking problems, the fix we had to do on both 3300 and 200 is have the carrier set there clocking in the router to clock both off of the carrier and PBX, as well as identify the lines with the carrier as a modem/fax

Alex

Swoby, aside from your post, there are several dozen (or more) posts about alarm, fax, and modem problems that arise when the poster went to PRI, 'flex circuits', VOIP, or SIP. The general recommendation is to return to POTS lines for critical circuits, or increased reliability. Between compression and 'clock' changes, trouble is pretty reliable on non-pots lines when trying to move data.