AT&T System 85 Telephone User Manual


 
PC Platforms (PC/PBX and PC/ISDN)
PC Platforms (PC/PBX and PC/ISDN)
Today, professional PC users seek to realize the promise of desktop computing productivity by
accessing multiple data sources—local and remote, internal and external. AT&T PC Platforms
provide both a high speed connection to the PC and an open software interface for creating appli-
cations that use the connection.
Overview
The PC platforms are ‘‘open platforms’’ that allow software developers to build applications that
take advantage of ISDN capabilities. The three platforms (PC/PBX, PC/PBX MicroChannel
Architecture, and PC/ISDN) support a common data Applications Programming Interface (API)
that provides applications portability between the DCP protocol and the ISDN-BRI. The common
API protects DEFINITY system customers who have invested in DCP while providing a large
installed DCP base for third party applications as well as the growing BRI market.
Platforms
The PC/PBX and PC/PBX MicroChannel Architecture platforms can be used with the DEFINITY
G1, G2, G3, System 75, and System 85. The PC/ISDN platform can be used with the DEFINITY
G2 and G3, and the AT&T 5ESS (Generic 5E4.2 and 5E5) switches. The platforms are particu-
larly useful for building applications for those users who wish to use their PCs as a terminal for a
host computer or wish to have their PC communicate with other PCs.
The connection between the PC and PBX can be either:
Digital Communications Protocol (DCP) interface—the protocol for System 75, System
85, DEFINITY G1, G2, and G3
ISDN Basic Rate Interface (BRI)—available with DEFINITY G2 and G3, and 5ESS
switches.
Physically, an expansion card is inserted in the PC and connected to the PBX via unshielded
twisted pair wiring. A separate card is needed for DCP and BRI. Since these cards feature a
voice port, they also support integrated voice-data applications as well as data networking.
PC/PBX and PC/PBX MicroChannel Platforms
The PC/PBX platforms provide standalone PC users with a fully integrated networking solution
that brings the benefits of high-speed, error free digital communications to the desktop. The
PC/PBX platform supports existing configurations in which both the voice terminal and the PC are
connected to the PBX via a single DCP line.
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