DTMF Detection Failure of TG Gateway - Change the DTMF Detection Mode

Applicability

• Firmware version: All
• Model: TGV2、TGV3

Problem Description

TG Gateway can not recognize the DTMF sent by the mobile phone when it's using the 3G or 4G network, whereas everything works well when it comes to 2G.

Analysis

The channel signal capture shows TG Gateway does receive related DTMF no matter 2G/3G/4G are used on the mobile phone. 

1. Three DTMF modes of SIP trunk including rfc2833, inband and auto are all tried but no luck.

TGV3 Path: Gateway>>VoIP Trunk>>Advanced>>DTMF Mode.

TGV2 Path: Gateway>>VoIP Trunk>>Advanced>>DTMF Mode.

2. Try to change the DTMF Detection Mode from hardware to software and it works!

TGV3 Path: Gateway>>Mobile List>>Advanced Settings.

TGV2 Path: there is no option on its web so customization is needed.

Log in the SSH of TGV2: 

https://support.yeastar.com/hc/en-us/articles/225066728-How-to-Login-the-SSH-of-Yeastar-MyPBX 

And refer this guide to customize the config file:

User Defined Configuration Modification

Solution

Change the DTMF Detection Mode from hardware to software.