Question

What DTMF characters can be recognized over the Voice API or SIP?

Applies To

• DTMF
• Voice API
• SIP

Answer

Using the Voice API or SIP, you can receive keypad input from a user via DTMF. For Voice API, this is collected using an Input action, while the DTMF will be relayed to your SIP endpoint for SIP calls.

The characters that the Vonage API Platform recognizes are:

1 2 3 4 5 6 7 8 9 0 * #

Be careful when building applications for different regions. Some regions will call # the hash key, while others call it the pound key. Also, some regions refer to * as the star key, while others call it the asterisk key.