[VoiceOps] Grandstream ATAs for Faxing

Nathan Anderson nathana at fsr.com
Tue Sep 9 19:58:28 EDT 2014

On Tuesday, September 09, 2014 7:40 AM, Jamey wrote:

> Anyone have other ATA's that seem to work well for faxing and credit
> card machines?

I don't have any experience with Grandstream, but in my experience the "right" answer to FoIP is T.38, as you alluded to.  But T.38 *only* deals with faxing; it is *not* a general-purpose modem-signal-over-IP solution.  So even if you find an ATA with a good T.38 implementation, this is not going to solve your credit card machine problem, only your faxing problem.  The equivalent to T.38 for bi-directional modem traffic over VoIP would be V.150, which as far as I know is very much still in its infancy, with very little industry support as of yet (either on the telco side or on the equipment side).

So your only solution for the credit card machines would be to continue to carry the traffic as G.711 PCM, which is never going to be predicably reliable.  My advice would be to implement T.38 on your network, deploy T.38 CPEs/ATAs to your customers, tell them that faxing is supported, but that any application they have that requires a modem (credit card swiper, postage meter, security system, etc.) is not, and that they should work with their vendor(s) to upgrade their modem-based equipment to models that support an ethernet/direct IP connection instead.

Nathan Anderson
First Step Internet, LLC
nathana at fsr.com

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