DTMF Problem on Toll Free calls over PRI

[MtNittany]

We recently started routing some of our outbound Toll Free traffic out over some LEC PRI's. We are getting complaints from users that when they dial a Toll Free # that requires a key selection to navigate an IVR, the DTMF tones are distorted. They can dial out just fine. Just on IVR menu's, it takes them several times to get the key they pressed recognized. This is not occuring on non-PRI trunks and COT's provided by the same LEC. We have a Nortel Option 11 PBX. Not sure if this problem is w/ our PBX, the LEC PRI's or on the far end.

Does not appear to be an issue on the far end as frustrated users have made calls from their cell phones and they do not experience any issues w/ DTMF recognition.

Any suggestions would be appreciated. Thx

 

[johnpoole]

could be a bad dtr but it sounds more like a patch issue

john poole
bellsouth business
columbia,sc

 

[telecom116]

Does the system have a TMDI card? I seem to remember an issue with certain TMDI cards providing bad DTMF tones, but this was several years ago. As johnpoole suggests I'd check patches first but you might also consider a hardware issue with the TMDI card.

 

[MtNittany]

This is our release info for the Option 11.
EXP CAB 2
VERSION 2111
RELEASE 25
ISSUE 40 B

By DTR, are you referring to a Digitone Receiver Card? If so, you would think outbound calls over multiple routes would be impacted. My situation seems to isolated to only outbound TF calls over these 2 LEC PRI's.

 

[telecom116]

Question - have you checked out the tones yourself (ie, called yourself using the PRI link then generating DTMF tones).

 

[MtNittany]

I have made several test calls to multiple Toll Free's over these PRI's and experienced the issue first hand. For instance, if I have to input a 6 digit Conf Code for our Conferencing system it might take up to 5 attempts for the 6 digits to be recognized properly. I don't know of a way that I could send the DTMF to myself to see what is being sent.

I did check the cards and both PRI spans are TMDI 1.5 DTI/PRI - NTRB21AB RLSE01

Thanks

 

[March71]

Question: If you called your cell-phone, do you hear tones when you press the numbers on your desk phone?

 

[MtNittany]

I do hear the tones on my cell phone, yes. In addition yesterday, I swapped out the TMDI card for a DTI/PRI card and the DTMF issue continues.

I spoke to the LEC and verified they are DMS 100 on their end. The RDB is set up w/ IFC as NI2 on my end. I may change this to see if it has any impact

Also this PBX has the DTR funtionality built in on the SSC Card.

 

[roupe]

They may be a DMS100 co but their dchan interface has to match yours for your pri to fly. Assuming that it is ,you may want to prt ftr FROM CDB IN LD 21 check these settings for end to end signaling. DTMF should be no...digital sets are not suppsode to hear dtmf..analog sets still connected to dtmf in pbx will.

EEST YES
DTMF NO
EESD NO

 

[Cosmicsniper]

If you have a spare SSC card to swap with, I might suggest that. Remember to swap all daughterboards, memory, and dongle.

I'd like to hear if this just started occuring or if it was only just noticed when routing to the specific LEC.

Vance Bagwell

 

[johnpoole]

EEST YES
DTMF NO
EESD NO

that is not the setup i use, if digital can or can't hear dtmf is usually decided by what the user expects.. those params either give feedback to the set or not, they do not change signals to the dch

john poole
bellsouth business
columbia,sc

 

[johnpoole]

on the d itself, dtmf is not sent.. you can see what is sent via enl msgi x on the d in ld 96.. your sending digital data at that point

john poole
bellsouth business
columbia,sc

 

[MtNittany]

My CDB shows:
EEST YES
DTMF YES
EESD NO
I would be reluctant to change out the SSC as I don't have DTMF issues over other routes. The issue only began a few weeks back when we began routing Outbound Toll Free over these LEC PRI's. I'm not certain I understand how enabling the D-chan msg would help if DTMF is not sent over the D?

 

[johnpoole]

you do not get dtmf across a d, but you can see if the switch is sending the digits or not, the problem may not be on your end at all.. if your sending digits and the far end ignores them, you can change the switch all day and not fix something that may not be broke

john poole
bellsouth business
columbia,sc