If you ever need to select voice menu options whilst on the phone, or are prompted to use your keypad during a call, you are using DTMF tones to indicate which numbers you are pressing. During testing we have found that the device performs best when the following DTMF options are enabled through the browser configuration.
Once logged into the base station, select the Settings tab followed by Telephony then Advanced Settings.
Under the section entitled DTMF over VoIP Connections please ensure that Send Settings: Audio and RFC 2833 are ticked and click on Set to save the settings.
You will then be able to send DTMF correctly using the service.