Capturing audio to troubleshoot line quality issues

Objective

To set up a rule in the routing table of a Dialogic 2000 Media Gateway Series (DMG2000) gateway to specify an outbound TDM channel for capturing the audio, mainly to troubleshoot problems where a line quality issue is suspected.

Reason

Since the audio capture can only be done on one channel, it is easier to set up a specific channel rather than wait for the right channel to be used or for the load on the DMG2000 gateway to be so low that the outbound channel would be the lowest one (Channel 1).

Procedure

To specify the channel, open the DMG2000 gateway configuration interface and go to Configuration > Routing table.

Click on the 'TDM Trunk Groups' radio button and create a new group as shown in this example:

Open

Give it the name you want and  specify the port and channel to be used. In this example the outbound call will go out on channel 12 of port 1.

Click on the 'Inbound VoIP Rules' radio button and add a new rule as shown below:

Open

You can then specify a called party number or a VoIP endpoint (or both). General filtering rules apply here - refer to the Dialogic Media Gateway documentation for more information.

In the 'Outbound Routes' frame, select the newly created Trunk Group as the outbound destination (circled in green in the example).

Make sure to move the new rule to the top of the list so that it gets matched before other rules that could have similar CPID or hostgroup matching rules.

Submit the new settings.

Go to the Trace/Logging screen.

Click on the Configure button for the TDM Capture and select the channel that was defined in the new Trunk Group, 12 in our example:

Click on Start.

Reproduce the problem quickly to avoid capturing too much silence; the capture starts immediately even if no call is active on the channel.

After reproducing the problem, click on Stop and then Download to get the recorded WAV file onto your PC.