Troubleshooting Transfers to IVR Autopay by Phone (DTMF Detection, Lag, etc.)

If you decide to enable a transfer from your main Billing phone number to the 1800 Notify IVR Autopay by Phone system, sometimes that transfer call quality or detection of DTMF touch-tones pressed by the caller to interact with the IVR does not always work as you would like. 


Handset Issues: The handset is not sending the DTMF tones correctly over the telephony lines. This could be because of the settings in the handset, software bug, poor quality reception, speaker/earphone mode, etc.

Carrier Issues: One or more carriers involved during the transmission of DTMF tones fail to transmit it properly (This could be due to a combination of the handset, operators, location/cell towers involved).

Environmental Factors: Any factor which can cause sound (DTMF tone) to be altered or lost, such as background noise, poor reception, poor audio quality, etc. can make it difficult to distinguish the DTMF tones, or can also lead to duplicate tones being detected (if a noise chops a single DTMF sound into two parts).

User Behavior: Problems might arise if a user provides DTMF key inputs in mute or speaker mode. It may also be because the user presses the keys too quickly for the DTMF to be interpreted.



This article has a few troubleshooting things to try:

STEP 1: Determine if you have any issue.

The easiest way to determine if you have an issue is this:

(A) Call the IVR toll free phone number directly and try some tests - enter an account number and authentication information (e.g. date of birth) a few times - say 3 times.

(B) Then call your billing office number and press the # to transfer to the IVR (e.g. "Press 1 to use our secure account system where you can check your balance and make a payment"). 
Repeat the 3 tests above from (A).

You should have 100% accuracy on test (B) compared to test (A).  If not, you know there is some issue.

STEP 2: Troubleshooting Methods

2.1. Check your phone system technical support site for any bugs/issues and verify that your phone system router software has been updated recently.

Sometimes your phone system router has an old version with a known issue.  In one example, we saw that a Cisco router software had a bug that duplicated most caller key presses on transferred calls resulting in the following: 

Caller presses 1-2-3-4

IVR hears: 1-1-2-3-3-4-4


IVR hears: (nothing - as if you did not press any keys)

Such a duplication of key presses (touch tones) will make the IVR unusable.


2.2. Verify that all of your phone system routers have been updated recently.

The symptoms of this issue are intermittent errors with caller key presses by callers (DTMF tones).  For example, every other call works perfectly, but the calls in between duplicate key presses or have some other problematic issue.

This can result if you have multiple routers for redundancy and calls going to the router causing errors only happen 1/2 of the time.  The other 1/2 of the time the calls are going through the router that is working perfectly.


2.3.  Make sure that your settings (Transmit and Receive Gains, etc.) on transferred calls are set correctly.

We had a client where only about 30% of all calls were detecting DTMF key presses by callers to the IVR on transfers. 

When the client adjusted the transmit and receive gains on transfers by about 2.0 Db on their PBX PRI interface, it worked perfectly - then 100% calls were successful.

So, there may be some settings (not software) that can be the source of issues with transfers to the IVR.


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