Determining the call type

After the incoming call has been authorized by call filtering, the call type is determined.

There are two call types associated with modems:

• acu

  Data over a modem

• acu_fax

  Fax over a modem

There are five call types associated with ISDN adapters:

• isdn_async

  Asynchronous data over ISDN

• isdn_sync

  Synchronous data over ISDN

• isdn_fax

  Fax over ISDN

• isdn_video

  Video over ISDN

• isdn_voice

  Voice over ISDN

Refer to the Callservices(4bnu) manual page for more information.

Other types of call (for example, PPP connections) can be auto-detected using the /etc/ics/Autoacts file (see Autoacts(4bnu) and pppsh(1M)). This file contains a list of byte sequences and associated services. The port monitor uses Autoacts to discover which service to invoke by matching its entries against an incoming byte sequence.