Troubleshooting DTMF
- For HD Phones ensure their DTMF Mode is set to RFC2833. This is set under Extension->Advanced.
- For IP550 and IP120 Phones set their DTMF Mode to SIP INFO.
- Ensure that the phones are configured through the PBX. If they are manually configured then you need to set the DTMF setting in the PBX and in the phone.
If the issue you are troubleshooting involves dialing * or # into an external IVR, you can navigate to PBXSetup->General and change the value for Feature Digit Timeout. This value is in milliseconds. It determines how long after you press a feature code digit, the PBX will wait before it sends the code as normal DTMF. Because ## and *# are feature codes, the PBX does not immediately send them. It waits temporarily to see if you are going to dial the complete feature code. If you set it below 2000, humans cannot manually activate features codes in most cases, but most phones can. Note the ## transfer feature code is used for call park keys on phones. If you change the feature digit timeout, save, apply. Then try to park a call by calling from Phone A to Phone B and pressing the Park key on Phone B