4.6.2. Getting Notification of DTMF Detection

Once DTMF support has been configured (see Section 4.6.1, Specifying DTMF Support), the application can specify which DTMF modes will provide notification when DTMF digits are detected. The events for this notification must be enabled; see Section 4.14, Enabling and Disabling Unsolicited Notification Events.

Once the events are enabled, when an incoming DTMF digit is detected, the application receives a GCEV_EXTENSION event, with an extID of IPEXTID_RECEIVE_DTMF. The GCEV_EXTENSION event contains the digit and the method as follows:

• IPSET_DTMF - The parameter set specific to DTMF.
  • IPPARM_DTMF_ALPHANUMERIC - For H.323, DTMF digits are received in H.245 User Input Indication (UII) alphanumeric messages. The parameter value is of type IP_DTMF_DIGITS. See Section 7.7, IP_DTMF_DIGITS for more information. For SIP, this parameter is not supported.
  • IPPARM_DTMF_RFC_2833 - DTMF digits received in the RTP stream as defined in RFC 2833. The parameter value is of type IP_RFC2833_EVENT.

Click here to contact Telecom Support Resources