Apple began developing its vision of personal computer telephony in the mid-1980s and released the MTA (Macintosh Telephony Architecture) in 1991, long before TAPI or TSAPI surfaced. One piece of MTA, the Telephone Manager, offers call-control services; another, the Telephone Tool, maps call control onto various kinds of telephony hardware. The crown jewel of MTA, though, is a suite of telephony Apple Events that abstract the Telephone Manager APIs and radically simplify the development of telephony-aware applications.
All this should have led to an explosion of telephony applications for the DSP-equipped (digital signal processor) AV Macs, which also come with PlainTalk, Apple's well-regarded text-to-speech and speech-recognition technologies. But while Telephone Tools have long existed for modems, ADB-based (Apple Desktop Bus) analog phone adapters, an
d even the InteCom switches in use at Apple, the AV Macs shipped without Telephone Tool support for the GeoPort Telecom Adapter, or phone pod, that connects these machines to analog phone lines. Lacking that support--which is now imminent, according to Michael Bayer, Apple's personal communications evangelist--AV Mac developers couldn't exploit the Telephone Manager APIs or the telephony Apple Events in POTS (plain old telephone system) environments.
Also imminent are PBX-oriented GeoPort phone pods, which will unlock the telephony capabilities of the Power Macs now flooding into corporate settings. Applications such as screen-based phone control, screen pops, database-driven dialing, IVR (interactive voice response), and fax on demand will become increasingly common on individual Mac systems.
What's less clear at the moment is how Macs tap into server-based telephony. "Apple has created very slick, powerful APIs for desktop telephony," says Peter Durlach, vice president of product development f
or Articulate Systems, developer of Voice Navigator and Power Secretary, "but the classic voice telephony applications--voice processing, IVR--are inherently server-based, and there's been no good way to connect to PC voice hardware sitting on the network." That situation may change soon, however. Apple's Bayer says that a forthcoming Telephone Tool will connect Macs to Dialogic's AppServer via Ethernet.
Apple's biggest contribution to computer telephony may turn out to be GeoPort, a 2-Mbps serial interface that can handle dozens of simultaneous data streams. "Think of it as a turbocharged version of Apple's existing serial port implementations," says Mark Orr, Apple's GeoPort business manager. "There's considerable headroom above 2 Mbps. The speed of implementation is really up to the host. GeoPort has the intelligence to negotiate the fastest host-supported transfer."
GeoPort seems likely to become a standard telephony interface not only on Macs but also on 80x86 PCs. That's great news for PBX
vendors who want to create desktop telephony hardware. The same GeoPort phone pod will be able to support TAPI applications on a Windows PC and Telephone Manager applications on a Mac.
Illustration: Graph: GeoPort Architecture
Each adapter vendor creates its own adapter handler--a software device handler--for its own hardware. Although the adapter hardware might be the same across platforms, each platform will require its own driver. The GeoPort serial driver handles all data streams and is specific to a given host. Real-time services require a real-time engine, usually a DSP in non-PowerPC Macs.
Macintosh Telephony
