The gateway can be configured to notify the outbound side for an inbound
call:
- on the first ring (ON-FIRST-RING)
- after the nth ring (AFTER-N-RING))
- after we received the caller-ID information (ON-CALLER-ID).
It is also possible to delay the outbound side notification action by few
milliseconds after the gateway met the specified condition.
NOTES:
- The "outbound side" is usually a SIP leg. But it can't be another
PSTN leg. The type of the outbound leg depends on routing-rules.
- The caller-ID information is not available when the gateway is
configured to notify the outbound side just after the first ring.