T.38 and Modems

[ralph]

Has anyone been able to make modems  (ie: HVAC modems, credit card machines, 7100) work when T.38 is enabled?   We had issues early on and have shy'd away from using T.38 because of it.  Don't know if it's been fixed yet or not.   Any success out there?

Ralph

[Mitel100]

I have always had big problems with this. whenever a Mitel or a Reseller do a SOW, they always forget to look at modems. Modems will not work with T.38 but I have been told, never tested PDQ machines will.

Within the IP network I have always had to create a small DPNSS network, for the modems to route across these. (Only if the PSTN is not directly connected to that system)

[ralph]

Thanks for the reply.  What a PDQ machine.  New term to me.
You would think that Mitel would set it up so that you can tell a route to use T.38 or not.   I don't like this set up at all.   Lost all control for these types of calls.   We've always been able to make modem and faxes work over the WAN by controlling the QOS.  Sometimes we'd have some trouble but most times not.  Just turn off compression.   Can't turn off T.38.   Now can't make work.   Last conversation I was involved with Mitel we were told they didn't have a problem with T.38 and modems and "oh, by the way, modems aren't supported acorss IP".   

But for some reason, stuck in the back of my mind, I think I heard the modem issue was fixed.   Am I wrong?

Ralph

[Mitel100]

PDQ is a term for a small Credit Card Machine. The term PDQ is widely used in the UK.

I had a really big install and ran into problems with these PDQ machines and modems almost stopped the install, it was only by saying that we would include DPNSS routes to the PSTN we went ahead.

In the UK it is a known problem.

[Mattmayn]

As far as I know modems do not work across T.38, and I don't think that Mitel intends on this happening any time soon. If you have local analog trunks for either backup or 911 on site route the CC machine out of that.