Hayes ISDN System Adapter Version 1.1

Hayes( ISDN System Adapter is the first external multimedia adapter with
superior voice and data capabilities for PC, workstation, and host
computer environments that supports both AT&T and Northern Telecom ISDN
central office switches and fully implements Hayes Standard AT Command Set
for ISDN.

The adapter implements Hayes AutoStream protocol as well as provides
direct access to the 64 kbit/s
B channel bit stream for transparent data transmission at the maximum B
channel rate.  The adapter implements the CCITT ISDN Basic Rate Interface
(2B+D) and supports standard analog telephones, answering machines, Group
III faxes and modems.  Hayes ISDN System Adapter is equipped with the
industry-wide standard RS-232 serial DTE interface for personal computers,
and the user can access voice and data services through this serial port
with Hayes Standard AT Command Set for ISDN.  A switch selectable V.35
interface is also available at the same connector.

Hayes ISDN System Adapter and Hayes ISDN PC Adapter are supported by
application programs now available from more than 20 software developers.
These third party developers are part of Hayes total ISDN Technology
Empowerment Program which extends from technical publications to training
seminars and Hayes Developer, Test and Training Labs.  These services
offer developers, end users and resellers comprehensive product support
unlike any other ISDN CPE vendor.  In addition, the architecture of Hayes
ISDN products has been designed to support National ISDN 1 specifications,
and Hayes will continue to work closely with switch vendors and service
providers to ensure that ISDN services based on National ISDN 1 are
deployed throughout North America.

Version 1.1 Enhancements

Macintosh Configuration Program - Hayes ISDN System Adapter Enhancements
for the Macintosh User Guide contains detailed instructions for
configuring the ISDN System Adapter with the new Configuration Program for
the Macintosh, using voice features through your telephone set, and
placing and answering data calls using Hayes ISDN Tool for the Macintosh.

Hayes ISDN Tool for the Macintosh Communications Toolbox - Provides easy
and complete access to the advanced data features of Hayes ISDN System
Adapter.  Settings provided by the tool are divided into four functional
areas, accessible through a list of panels.  Each area controls an aspect
of Hayes ISDN System Adapter or the connection.  Written to the
specifications of the Macintosh Communications Toolbox, Hayes ISDN Tool
has been designed so that Hayes ISDN System Adapter users can take full
advantage of ISDN data capabilities through existing applications which
support the Macintosh Communications Toolbox.

Improved DOS Configuration Program - Defaults have been updated in Hayes
ISDN System Adapter Configuration Program for the PC to reflect the most
common settings for easier set up and use.

Enhancements to Hayes Standard AT Command Set for ISDN - Supports latest
enhancements to Hayes Standard AT Command Set for ISDN, including new
defaults, options and error codes.

Caller ID Feature - Implements the Caller ID feature for data calls (X.25
PSD or CSD) which enables the called adapter to have information such as
the calling party number and the called party number available to convey
to the user's application.

ISDN SERVICES (Basic Rate Interface)

Data Capabilities - Hayes ISDN System Adapter supports B channel circuit
switched data (CSD) and
B channel packet switched data (PSD), as well as D-channel PSD over the
ISDN Basic Rate Interface.  For CSD calls, the ANSI V.120 protocol is used
for rate adaption and error-control for asynchronous host connections, and
direct access to 64/56 kbit/s B channel bit stream is used for synchronous
host connections.  PSD calls use CCITT X.25 protocol recommendations
including X.3/X.29 packet assembler/disassembler (PAD); X.28 functionality
is mapped to AT Commands.  The D channel and a
B channel can be used simultaneously for data calls with either channel
supporting multiple data sessions, for a total of four sessions.  Multiple
simultaneous session support requires use of Hayes AutoStream protocol by
the host computer application.

Voice Capabilities - Circuit switched voice (CSV) is available on one of
the B channels using a standard analog phone attached to the RJ11
connector on the adapter's back panel.

ISDN voice services provided include basic centrex features: conference,
drop, transfer, hold and retrieve.  Other Central Office (CO)
switch-supplied supplementary voice services are supported, such as
calling line identification, two call appearances, speed calling, call
forwarding, call park, call pickup and others.  Basic voice features, and
some supplementary voice features, can be accessed from the analog phone
by using hookflash and dialed access codes.  Other supplementary features
and feature button access are supported through Hayes Standard AT Command
Set for ISDN.

ISDN SERVICE OPTIONS

Combinations of ISDN services are dependent on ISDN line provisioning.
Hayes ISDN System Adapter supports line configurations that provide up to
one B channel circuit switched voice service, one
B channel data service for circuit switched or packet switched
connections, and simultaneous
D channel packet switched services.

ISDN SWITCH COMPATIBILITY

ISDN Switch Support - Hayes ISDN System Adapter is compatible with the
AT&T 5ESS switch, Generic 5E4.2, 5E5, 5E6 and 5E7; and the Northern
Telecom DMS-100 switch, BCS-29, BCS-31 and
BCS-32.  The architecture of ISDN System Adapter has been designed to
support National ISDN 1 specifications.

Product Upgrades - Hayes ISDN System Adapter has been designed to support
future switch software releases, including the National ISDN 1 standards.
Hayes continues to work closely with ISDN switch manufacturers to develop
compatible products which take advantage of the latest switch
enhancements.  An upgrade program for Hayes ISDN products ensures
availability of firmware upgrades as new releases are made available.

Network Support - Supports 64K unrestricted or 64K rate adapted from 56K
network transmission for circuit switched data calls.

ISDN STANDARDS

Hayes ISDN System Adapter supports Northern Telecom DMS-100 and AT&T 5ESS
implementations of CCITT Q.931/I.451 signaling and call control, and CCITT
Q.921/I.441 data link layer and error-control.  Hayes ISDN System Adapter
also supports the CCITT I.430 network interface, ANSI V.120 rate adaption,
and CCITT X.25 packet switching.

INTERFACES

Analog Telephone Interface - A standard analog telephone interface is
provided via an RJ11 connector on Hayes ISDN System Adapter's back panel.
The adapter provides the necessary ring voltage and supports up to three
typical analog telephone devices such as modems, Group III FAX and
answering machines.

ISDN Line Interface - The ISDN Basic Rate S/T interface is provided at an
8-pin modular connector on the back panel.  Passive bus support is
available, allowing multiple ISDN devices to access a single ISDN line
when using the Northern Telecom switch.

RS-232/V.35 Host Interface - An RS-232 serial interface supports
autobauding up to 38,400 bit/s for the host computer.  A switch selectable
V.35 interface is also available at the same connector; an optional
adapter plug converts the DB-25 connector to the standard V.35 connector
and is available from Hayes Customer Service.

LED Status Indicators - Hayes ISDN System Adapter status is indicated by
eight LEDs which inform the user of various aspects of adapter operation
and ISDN and DTE connection status.

TERMINAL ADAPTER CONTROL AND OPERATION

Hayes Standard AT Command Set for ISDN - Hayes Standard AT Command Set
for ISDN supports high speed data connections and access to ISDN services
while emulating a Hayes Smartmodem*.  This capability allows users and
developers to make a smooth transition to ISDN using a familiar
application interface.

Hayes AutoStream - Hayes AutoStream for ISDN provides multiple session
capability over a single physical asynchronous link.  Up to four channels
are supported and can be individually programmed to control the voice
service and multiple data sessions.

Hayes ISDN Tool - Hayes ISDN Tool is a connection tool, for use with the
Macintosh Communications Toolbox, that provides easy and complete access
to the advanced data features of Hayes ISDN System Adapter.  This utility
enables Hayes ISDN System Adapter to take full advantage of ISDN through
applications supporting the Macintosh Communications Toolbox.

DATA SPEEDS AND FORMATS

When using Hayes Standard AT Command Set for ISDN, the following
asynchronous character formats are supported in the adapter according to
the specified speeds and protocols:

Asynchronous Data Formats

        7 data bits and 1 parity bit; even, odd, mark, or space
        8 data bits with no parity
        1, 1.5, or 2 stop bits in the DTE to DCE direction
        1 stop bit in the DCE to DTE direction

Data Speeds

        300, 1200, 2400, 4800, 9600, 19,200, and 38,400 bit/s asynchronous
        56,000 and 64,000 bit/s synchronous (B channel direct connect)

CONFIGURATION

Installation programs for DOS and Macintosh computers help the user set
up and install Hayes
ISDN System Adapter.  Configuration is simplified by these user-friendly
programs and the thorough documentation included with this product.

OPERATING ENVIRONMENT

Hayes ISDN System Adapter is for use with personal computer, workstation,
and host computer environments.

AGENCY APPROVALS AND CERTIFICATIONS

        FCC Part 15 Class B
        DOC Standard CS-03
        ETL Certification
        CSA Certification

SERVICE AND SUPPORT

Technical Support - Applications consultants and technical engineers for
Hayes ISDN System Adapter are available at Hayes ISDN Technologies at
415/974-5544.  Hayes also offers 24-hour electronic support through Online
with Hayes, Hayes Bulletin Board System, in the U.S. at 404/HI MODEM,
800/US HAYES or 404/729-6525 (ISDN users), in London at 081/569-1774, and
in Hong Kong at 852/887-7590.  Hayes also maintains an ISDN Developer,
Test and Training Lab at Hayes ISDN Technologies where third party
developers and others interested in testing ISDN applications can gain
access to ISDN lines from both AT&T 5ESS and NT DMS-100 ISDN switches for
testing with Hayes ISDN products.

Product Warranty - Hayes ISDN System Adapter is backed by a two year
limited performance warranty.  Hayes guarantees that the product will
perform as stated in the user documentation specifications.  Since the
company's emphasis on quality results in extremely reliable products,
Hayes can provide outstanding repair service when the rare, but
inevitable, service is required.  While Hayes warranty service turnaround
is a maximum of three days, over 98 percent of the individual units
received for repair are returned to customers within 24 hours.

Developer Program - Hayes ISDN Developer Program provides qualified third
party developers the support and information they need to develop
high-quality, user-friendly applications for ISDN.  The program includes
access to Hayes Developer, Test and Training Labs in San Francisco, CA and
Beeston, Nottingham, England, technical telephone support, discount
product purchases, and access to Hayes ISDNBIOS interface developer tools.

Product Training - Hayes offers a complete ISDN Product Training Program
which includes intensive, two day training classes that are conducted on a
monthly basis at Hayes ISDN Technologies.

Hayes ISDN Newsletters - An ISDN newsletter containing Technical Notes,
Application Notes and Developer Notes is published periodically and is
available to customers, developers and others interested in ISDN.

To find out more about Hayes Leadership in ISDN Technology Empowerment,
call or write to one of the following locations:

Hayes World Headquarters:  Hayes Microcomputer Products, Inc., P.O. Box
105203, Atlanta, GA  30348; 404/441-1617 (Customer Service); 1-800-US
HAYES, 1-404-HI MODEM or 1-404-729-6525 for ISDN Users (Hayes Bulletin
Board System).

Hayes ISDN Technologies:  Hayes Microcomputer Products, Inc., ISDN
Technologies, 501 Second Street, Suite 300, San Francisco, CA  94107;
(415) 974-5544.

Hayes Canada:  Hayes Microcomputer Products (Canada) Limited; 295 Phillip
Street, Waterloo, Ontario, Canada, N2L 3W8; 519/746-5000.

Hayes Europe Region:  Hayes Microcomputer Products, Inc., 1 Roundwood
Avenue; Stockley Park, Uxbridge, Middlesex, UB11 1AE; 011-44-81-848-1858;
011-44-81-569-1774 (Hayes Bulletin Board System).

Hayes Asia Region:  Hayes Microcomputer Products (Asia) Limited; 39/F,
Unit B, Manulife Tower, 169 Electric Road, North Point, Hong Kong;
011-852-887-6836; 011-852-887-7590 (Hayes Bulletin Board System).


Hayes, the Hayes icon, and the Hayes logo are registered trademarks and
Smartmodem is a trademark of Hayes Microcomputer Products, Inc.  Other
trademarks mentioned in this summary are trademarks of their respectve
companies.  The Consultative Committee on International Telegraphy and
Telephony (CCITT), part of the International Telecommunications Union, is
the United Nations agency responsible for development of standards for
international data communications.