Handbook:Advanced Server Configuration:Distinctive Ring

Distinctive ring is a feature provided by phone companies whereby multiple phone numbers can be directed to a single phone line with different ring patterns for each phone number. This is a simple mechanism that can be used to distinguish between incoming fax, voice, and data calls (i.e. all fax calls are directed to one number, voice to a different number, and data to a different number).

HylaFAX supports distinctive ring capabilities through the RingFax, RingData, and RingVoice modem configuration parameters. Modems that support distinctive ring send a different RING status message to the host depending on the ring pattern presented by the phone company. By setting the configuration parameters faxgetty will match the appropriate RING status message and use the information to treat the inbound call as fax, data, or voice before answering the call. For example,

RingFax:       RING1           # treat ring pattern 1 as fax
RingData:      RING2           # treat ring pattern 2 as data