Ringing Types and Intercom
Digium phones support several different types of ringing:
- Normal Ringing - normal
- One Ring followed by automated Answer - ring-answer
- Immediate Answer, No ringing - intercom
- Visual only, No ringing sound - visual
When an incoming call is received, the phone will look for an ALERT_INFO SIP header, and compare the received header against its configuration, as parsed from its Config XML or via the DPMA alert configuration options.
Affecting the ring type from the Asterisk dialplan requires use of the alert_info SIP header. This header should be added into the dialplan before executing a dial to the phone, as such: