DTMF Works for Some Callers, Not for Others

[Wisco33]

Hey all,

I have a customer with a TDA50 and TVA50. They had been up and running without issue for many years and are a small site with 5 DPTs and 3 Lines (Spectrum Coax POTS).

However, they recently moved to a new location. We relocated their system and made no programming changes, and Spectrum had installed new equipment at the new site. All is working perfectly fine except when some outside callers call in and get voicemail, DTMF does not work. For other callers though, it does work. It does not seem to be based on specific carriers either, as two people who work there are husband and wife, both have Verizon and on the same plan, and the husband has no issues when testing but the wife does. This all started happening after the relocation.

Now, obviously there is nothing in the systems to discriminate calls like this. Doing my due-diligence, I tried another TVA and had same issue. I also tried an NS700 and had the same issue. To further put this on Spectrum (but Spectrum specifically at this site), I forwarded calls through the PBX (the NS I brought to site) to another customer of ours who is fully automated (thus bypassing both the customer's PBX and VM) and still had the issue. When I called that other customer directly however, there are no DTMF issues.

Spectrum of course is not giving any explanation but did send a tech who did swap out the modem, to no avail.

Has anyone ever experienced this and if so, any fix???


Thank you!

 

[martincom]

I'm thinking it has something to do with the DTMF being regenerated, but too short of duration. Can you monitor the incoming line, while duplicating the failure, and check what the duration of the DTMF burst is?

I had similar issue, but with an OBI -Talk VOIP analog adapter interfaced to Google Voice. When I phoned my bank's automated system, it would not recognize the digits when dialed. I had the same issue with a few other services where I would have to over dial an access code. The issue was I had configured the OBI-Talk for an alarm service. Our alarm system reported to the monitoring service the OBI-Talk/Google Voice landline. The alarm panel utilizes short duration timed DTMF as the reporting conveyance. When configuring the OBI-Talk for an alarm service, it re-generated the DTMF in those short burst digits, to be compatible with the monitoring station equipment---which were too short for my bank's system to detect. To resolve the problem, I only enabled alarm service on the line serving the alarm panel. I made it a point not to utilize that line when phoning the bank's system.