Knowlege base

Troubleshooting

Article ID: 155
Last updated: 30 Dec, 2016

How to use the troubleshooting guide

This page describes basic troubleshooting techniques and most frequent issues you may face during the application  setup and usage.

The first part describes the basic tests to be made after you completed the configuration task list. Those test can reveal issues in the configuration and can help you to identify them.

The second part is a list of common issues and their causes. Look for the symptom and follow the tips. To know how to configure the product, please refer to the relevant pages in this guide.

Please understand that the problem may be related to complex PBX and network configurations, and that is not possible to list all them all. This guide must be considered as a tool to guess the origin of the issue.

1. Post installation tests

Create a new Echo service from the Add new service page. Make sure the IVR Module can receive DTMF tones placing a test call from the PSTN with your mobile phone. Press each button on the keypad once, and the IVR service will tell you if it received the  key code, or if it received the same code twice.

2. Common issues

The IVR service cannot be reached (does not answer the call)

Define a QME queue and call it from the same phone. If you can call the QME but you cannot reach an IVR service, then there is a problem with DTMF negiotiation.

Please make sure your PBX accepts RFC2033 sip DTMF capability.

No DTMF is received or each DTMF is received twice

Please make sure your PBX does not send OOB (out of band) DTMF.

3. Reading Wireshark captures

If you capture the network communication with Wireshark or with another packet sniffer, this is what you should see in the SIP call flow.

When a new call arrives, the PBX sends an INVITE to the IVR module. IVR responds with TRYING, RINGING and OK. Ok has SDP headers which include codec and DTMF capabilities.
After the OK, the PBX should send ACK SDP and begin to send the RTP stream encoded with one of the supported codecs (G.711, G.729, and G729a). IVR will send RTP stream too, if audio prompts are configured in the behavior. 

If the call must be transferred, IVR will send a REFER with the new destination. The PBX will answer 202 accepted and send at least two NOTIFY messages to tell IVR that the destination is ringing.  The NOTIFY messages should contain TRYING, RINGING.

When the transferred call is answered, the PBX will send a BYE, followed by a NOTIFY (containing OK) to signal that the transfer is complete.

If the transfer fails, one of the NOTIFY messages contains the error code (e.g. 404 NOT FOUND).

Checking DTMF tones

Per RFC2833 standard, the tones are sent out of band in the in RTP stream. The Payload type is 101.

In the capture you should see something like:

a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16

4. How to get the log files

The application log files are shared with Queue Manager Express. You need to get the log files only if requested by Imagicle Support Team. To create the log files, access the Support page in teh Admin menu of the web interface.

On the bottom of the page, make sure "Enable log" is ckecked. Then perform the test or replicate the issue. At the end of the test, return to the support page.

In the "Extract for Application" drop-down list, select "Queue Manager Enterprise" and press the "Extract" button.

Article ID: 155
Last updated: 30 Dec, 2016
Revision: 10
Views: 239
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