RFC 2833 telephone-event duration intervals

If an incoming SIP INFO message’s DTMF indication duration is unspecified, the Oracle® Enterprise Session Border Controller, uses a default 250 ms duration for the generated RFC 2833 telephone-event. Otherwise, the SIP INFO’s specified event duration is used. RFC 2833 telephone-event packets are still generated at 50 ms intervals upon egress. At the conclusion of the DTMF indication, the three end-event packets are sent. The packet arrangement when the user presses the digit 5 for 160ms, with the default 50ms interval follows:

When either no DTMF event duration is specified, or the event duration is less than the 50ms default minimum, you can set the default RFC 2833 telephone-event duration using default-2833-duration parameter in the media manager configuration. This is the value that the Oracle® Enterprise Session Border Controller, uses for the duration of a telephone event when none is specified in the incoming message. The default-2833-duration’s valid range is 50-5000ms. The Oracle® Enterprise Session Border Controller, also uses this configured value when it receives a SIP INFO message with a duration less than the minimum signal duration.

You can configure the minimum duration at which RFC 2833 telephone-events are generated by the Oracle® Enterprise Session Border Controller, using the min-signal-duration option in the media manager configuration, thus changing the lower threshold of the default-2833-duration parameter from 50 ms to your own value. If the duration the Oracle® Enterprise Session Border Controller, receives is less than the threshold, it uses the value configured in the default-2833-duration parameter.

Note:

Timestamp changes and duration changes only take effect when the 2833 timestamp (rfc-2833-timestamp) is enabled in the media manager configuration. If you enable the rfc-2833-timestamp parameter, but do not configure the default-2833-duration parameter, the default-2833-duration parameter defaults to 100 ms.