atcomsystems.ca/forum Forums TDM Business Telephone Systems NEC Telephones & Systems Problems receiving Sprint DTMF tones??

Short version: Our 2400 PBX is not processing digits correctly (voicemail prompts, IVR account access, etc) ONLY from calls on Sprint phones. Not sure if the problem is on Sprint's end, or something on our 2400 PBX?

Long version:
Hi, we have a NEC 2400 PBX receiving DID lines via 2 PRI's, and we're using the NEAXmail AD-64 voicemail system. For the last few weeks I have been getting lots of reports of phantom issues related to auto-attentdant/phone trees. Specifically, users or the general public will report that the one-key dial options don't work on the phone trees -- they get an error message, or told that they chose an invalid option, when they swear they have entered the correct option.

Additionally, I was able to witness a user having a problem checking her voicemail remotely from her cell phone. She would dial our voicemail pilot number and then press the option to access her extension, but 9 out of 10 times the system would go back to the main greeting loop (as if she had entered a bad extension). I tested it myself many times using her phone. As I said, maybe 1 in 10 times it WOULD work as expected, which is even more bizarre. And the problem was not tied to her extension -- I could repeat the problem using my own extension, from her cell phone, but not from another cell phone.

We are getting the same kind of reports on a separate IVR system (not part of our AD-64 voicemail) that takes payments. A significant number of callers are saying they're entering their account numbers correctly but being told they entered an invalid account number.

I have been unable to reproduce ANY of these problems from my own cell phone or from a Dterm... until today, when I learned that the ONLY people reporting problems are using Sprint cell phones (most of us in the organization use Verizon cell phones, myself included, and we have no such problems). To the best of my knowledge every report of this problem came from a Sprint phone user.

My only thought is that something about the DTMF tones that Sprint is sending are not being interpreted properly by the 2400 PBX, or else there is some other problem on Sprint's end.

Problem is, I have no idea where to even begin troubleshooting this... Any ideas??

Thanks!

Jesse

I had a similar problem with a 8500. People calling in from a third party cell carrier got a wrong number. The same wrong number, and the owner of that number kept calling us to complain. We traced it starting with Verizon (our carrier) who said that number range was leased to Sprint. We got Sprint on the phone and they finally admitted that they had several cell towers down which caused the issue. I'd pursue it with Sprint and escalate it up their ladder of support.

OK, I will try to run it up the support chain at Sprint and see if I get anywhere.

In the meantime, I got ahold of a Sprint cell phone and was able to do some more troubleshooting. I used the status monitor tool in my NEAXmail voicemail server to monitor the DTMF tones I was receiving when I called in from that phone. Looks like the problem is that we're seeing double digits. For instance, I might see 112345677899.

Is there an interdigit timing feature on the 2400 that I can adjust?

Had this same problem with double digits on a DSX, Cebeyond carrier and Cisco router from them.
After much gnashing of teeth, found that a setting called DTMF S
under a VOIP setting in router had to be ON.
Was most pronounced with I Phones. All complaints gone after this was done.

Yeah, a bit of Googling has revealed a number of people with VOIP setups experiencing issues like this, which makes a bit of sense due to the nature of VOIP, but I've never experienced anything like this with the 2400.

I was able to log a service request with Sprint. They were surprisingly cooperative and didn't seem at all hesitant to pass it on to their advanced network team for troubleshooting. They promised an update within 48hrs... we'll see.

There was only one tech at Cbeyond that knew of this setting, took 3 days to get to him. This is normally on at default but for some reason had been turned off on that router.

Is it OK from Verizon phones?? Had this once from CDMA phones but Ok from GSM types..

Well Sprint called back and said they made "network corrections". As of now, Sprint calls into our voicemail server are working normally, and I can see the DTMF tones are not being doubled.

However, our IVR system (separate from our voicemail server) is still not working properly with incoming Sprint calls, so the problem isn't 100% resolved it seems.

But either way, looks like this is a network issue and not something in the PBX. Thanks for the input all.