Enabling Call Waiting

The Call Waiting feature enables busy FXS endpoints connected to the device to accept an additional (second) call. If an incoming IP call is designated to a busy port, the called FXS endpoint hears a call waiting tone (several configurable short beeps) and can view the Caller ID of the incoming call (for Bellcore and ETSI Caller IDs). The calling party hears a call waiting ringback tone. The called party can accept the new call using hook-flash and can toggle between the two calls. To indicate call waiting, the device sends a SIP 182 (Call Queued) response. The device identifies call waiting when a 182 (Call Queued) response is received.

The feature is applicable only to FXS interfaces. FXS interfaces support the calling and called sides.
You can enable call waiting per port in the Call Waiting table (see Configuring Call Waiting). For ports that are not configured in the table, call waiting is according to the global parameter, as described in the procedure below.
To enable and configure call waiting:
1. Open the Supplementary Services Settings page (Setup menu > Signaling & Media tab > Gateway folder > DTMF & Supplementary > Supplementary Services Settings).

2. From the 'Enable Call Waiting' drop-down list (EnableCallWaiting), select Enable.
3. Configure call waiting indication and call waiting ringback tones in the Call Progress Tones file (see Call Progress Tones File). You can configure up to four call waiting indication tones (see the FirstCallWaitingToneID parameter). To configure call waiting tones per FXS port(s) based on source or destination number, see Configuring FXS Distinctive Ringing and Call Waiting Tones per Source/Destination Number.
4. In the 'Number of Call Waiting Indications' field (NumberOfWaitingIndications), enter the number of call waiting indications that can be played to the endpoint.
5. In the 'Time Between Call Waiting Indications' field (TimeBetweenWaitingIndications), enter the time (in seconds) between consecutive call waiting indications.
6. In the 'Time Before Waiting Indications' field (TimeBeforeWaitingIndication), enter the delay interval before a call waiting indication tone is played to the busy endpoint. This enables the caller to hang up before disturbing the called party with call waiting indications.
7. In the 'Waiting Beep Duration' field (WaitingBeepDuration), enter the duration (in msec) that the call waiting indication is played to the endpoint.
8. From the 'Enable Hold' drop-down list (EnableHold), select Enable to enable call hold.