Unicall Support for MacOS X
Telephony Hardware Abstraction
Unicall is a vendor-independent hardware abstraction layer library for telephony interfaces. It is based on the call model of ISDN and SS7, supporting a broad range of telephony interface technologies, reaching from analog telephony devices to T1/E1 interfaces for primary rate ISDN. Unicall presents a unified interface through which telephony applications such as Asterisk are able to communicate with a variety of different telephony interfaces and protocols.
Unicall Architecture
The following block diagram shows how Unicall integrates with the Asterisk telephony server. Other telephony servers, e.g. CallWeaver can utilise Unicall in a similar fashion.
Device Driver Conduits
The Unicall library is cross-platform and open source. However, device drivers are vendor and platform specific. In order to interface between the Unicall driver API and a given device driver on a given platform, a conduit may be needed to translate between Unicall and the vendor specific driver API.
Sunrise Telephone Systems is working on two such conduits to allow the use of telephony interface hardware on MacOS X via Unicall:
AppleModem Conduit — to interface between Unicall and Apple's modem device driver to allow the use of the Apple USB modem as an FXO device¹
a MacOS X device driver for a USB based BRI ISDN interface which conforms to the Unicall driver API to connect to a Basic Rate ISDN voice circuit
¹ The upcoming AppleModem Conduit will make it possible to use one or more Apple USB modems (retail $49 at the Apple Store) as a PSTN line interface to connect one or more analog telephone lines to Asterisk or CallWeaver running on MacOS X.
