ATT System 25 Reference Manual

							OVERVIEW
l The integrated voice-data dialing plan recognizes the different types of data
endpoints (digital/analog and remote/local) in a connection and automatically inserts
the required data communication equipment.In addition, autobauding supports the
alignment of equipment with the capacity to transmit at different data rates.
l Station Hunting supports the use of a single dial code to access a group of host
computer ports.
l Terminal Dialing provides the user with fast access to data communications via
keyboard dialing at a terminal or PC.
l Command Mode provides a menu of data services supporting terminal dialing and
display and control of user data port options.A user friendly Change Options menu
is provided for user administration of data options.
l Expert Mode is an enhancement that provides an alternative method of accessing
Command Mode functions.It eliminates the display of menus and allows multiple
commands to be entered on a single line.Expert mode is suitable for use with
computer-driven scripts for call setup.
l Communication Access Manager (CAM) is an MS-DOS* software application that
provides a phone manager for placing voice and data calls for the user and VT100†
terminal emulation.CAM may be used on either STARLAN NETWORK client
workstations or on PCs connected to System 25. CAM has a 200-entry directory
with one-touch dialing for both voice and data calls and auto-login capability for data
calls to host computers.CAM’s Remote Access feature provides password
protected unattended access to PC files and electronic mail. File transfer is
supported with the popular XMODEM protocol.
l STARLAN NETWORK ACCESS is an MS-DOS software application that allows PCs
not connected to the STARLAN NETWORK to call through the System 25 STARLAN
NETWORK Interface and run STARLAN NETWORK client software to access file and
printer servers on the STARLAN NETWORK. ACCESS uses a PC’s serial
communications port to communicate with the STARLAN NETWORK Interface.
ACCESS is compatible with NETBIOS, permitting execution of most applications
written for the IBM‡ PC Network and IBM Token Ring Network.
* Registered trademark of Microsoft Corp.
† Trademark of Digital Equipment Corp.
‡ Trademark of International Business Machines Corp.
1-12 
						

							OVERVIEW
Growth & Rearrangement
Historical data indicates that clients in the System 25 station range have a need for
communications systems capable of significant growth and rearrangement. Clients need
flexibility over the life of the system to easily add capacity, move stations, modify cost control
options, etc. The architecture of System 25 was implemented with the objective to meet this
need.
l Advanced Administration (optional) is an easy-to-use, menu driven personal computer
software package for configuring the rich set of system options. Versions of this software
are available for both MS-DOS and UNIX personal computers.
l Uniform Wiring Plan (four-pair) allows a building to be prewired for the rich set of AT&T
Small Business PBX service offerings.This modular wiring plan supports client
reconfiguration of an office with variations in station type (Analog, MET, MERLIN
CommunicationsSystem,futures) and
data configurations (LAN, asynchronous,
synchronous). It supports simultaneous voice and data from standard 4-pair modular jacks.
l System 25/75/85 and DEFINITY™ Communications System, Generic 1 and Generic 2
Standard Architecture supports efficient growth with modular cabinets, universal carrier
slots, nonblocking network, and uniform wiring plan.Every circuit slot in the system can be
used for trunk cards or voice/data station cards. All these attributes allow the client to add
future capability without breakage and re-engineering of existing equipment. Thus, the
client is able to minimize initial investment while not restricting future growth.
Over time, the type of tools and facilities that a business utilizes changes. It is important that
a PBX provide support for the full set of telephone company network options over its
installed life, even when only a subset is initially used. Trunks link two switching systems,
such as System 25 and the local Central Office or System 25 and another PBX. System 25
supports five different telephone company trunk interfaces to provide desired connectivity at
minimum expense.Thus the opportunity exists to select the best trunk types, depending on
tariffs and customer needs. For example:
l Loop Start (LS) trunks for public network access at minimum tariff. These trunks
handle outgoing and incoming attendant calls, incoming DGC calls, outgoing pooled
facility calls, and personal line calls.
l Ground Start (GS) trunks for public network access. These trunks handle the same
type of calls as LS trunks. They provide protection against call reorigination without
toll restriction, more reliable automatic route selection, virtual facilities, SMDR, and
CAS. Simultaneous incoming and outgoing call seizure of the same trunk under
heavy traffic conditions is essentially eliminated with ground start trunks. GS trunks
should usually be selected in preference to LS trunks unless tariff considerations are
overriding. Note, however, that Centrex Service requires LS trunks.
l Direct Inward Dialing (DID) trunks for dialing a station directly from outside (attendant
assistance not required). Outside dial access to stations, trunks (optional), and
answering groups (Direct Group calling) is provided.
1-13 
						

							OVERVIEW
l Tie Trunks for linking PBXs with dedicated private circuits for high volume calling.
Dial access to stations, other trunks, answering groups (Direct Group Calling), and an
Electronic Tandem Network endpoint capability are provided.
l Off-Premises Stations (OPS) allow single-line voice terminals and key systems to be
located remotely and connected to System 25 via arrangements with the local
telephone company.This service is used to provide users at secondary sites (or
their residences) many of the same features as an on-premises single-line station.
To enhance the usage and control of the above set of network facilities, System 25 provides
the rich set of access features outlined in the Outgoing Business Communications section.
In addition, System 25 can support networking between systems by:
l Serving as an endpoint on an electronic tandem network (ETN) using its tie trunks
and flexible dialing plan.
l Serving as an off-network or on-network access point with its dial access/transfer
between tie trunks and telephone company trunks (LS/GS/DID). This allows usage of
tie trunks to reach a distant System 25 and then connect through that System 25 to
local telephone company facilities to complete the call.
To support efficient utilization of trunks, they can be grouped together (up to 16 groups) if all
trunks in the group perform the same function.This resource pooling provides better service
with a given number of trunks, and simplifies administration and calling.
Types of trunks that can be assigned in System 25 are as follows.
l Central Office, which provide a link with the local telephone company for incoming
and outgoing calls (LS/GS)
l Foreign Exchange (FX), which connect to a CO other than the local CO for high
volume calling to/from a distant location
l Wide-Area Telecommunications Service (WATS), which connect to an Outward WATS
office or a dial “800” Service Office
l Direct Inward Dialing (DID), which provide incoming service from a CO to directly
access a station or facility (STARLAN NETWORK interface, trunk group)
l Tie, which provide a link with another private switching system.
To support efficient utilization of this rich set of network options, System 25 provides the
functions outlined in the Incoming and Outgoing Business Communications sections.
Conclusions
System 25 has been targeted at providing excellent small business communications
capability at the right price.The thousands of systems in service in the first 2 years of
production have confirmed that these capabilities are an excellent match with small business
customers’ communications needs.
1-14 
						

							FEATURES AND SERVICES
Introduction
Account Code Entry, Forced
Account Code Entry, Optional
Attendant Call Extending
Attendant Camp-On
Attendant Cancel
Attendant Console, Direct Trunk
Attendant Console, Switched Loop
Attendant Direct Extension Selection
Attendant Forced Release (SLAC Only)
Attendant Join (SLAC Only)
Attendant Message Waiting
Attendant Position Busy
Attendant Release
Attendant Return Coverage On Busy
Attendant Return Coverage On Don’t Answer
Attendant Source and Destination (SLAC Only)
Attendant Splitting One-Way Automatic
Attendant System Alarm Indication
Automatic Intercom
Automatic Route Selection (ARS)
Bridging of System Access Buttons
Busy-To-Idle Reminder
2-1
2-8
2-11
2-14
2-16
2-18
2-19
2-24
2-34
2-39
2-40
2-41
2-43
2-46
2-48
2-50
2-52
2-53
2-54
2-55
2-57
2-67
2-74
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							Call Accountability
Call Accounting System (CAS)
Callback Queuing
Calling Restrictions
Call Management System (CMS)
Call Progress Tones
Call Waiting
Command Mode
Communications Access Manager (CAM)
Conference
Conference Drop
Coverage, Group
Coverage, Individual
DS1 Facility Interface
Data Call Setup
Data Services Overview
Data Terminal Dialing
Dial Access to Message Waiting Indicators
Dial Plan
Dictation System Access
Digital Tape Unit (DTU)
Direct Group Calling (DGC)
Direct Group Calling Delay Announcement
Direct Inward Dialing (DID)2-75
2-76
2-81
2-88
2-91
2-94
2-95
2-97
2-101
2-103
2-106
2-108
2-114
2-117
2-128
2-129
2-135
2-139
2-140
2-143
2-145
2-147
2-150
2-152
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							Directory
Direct Station Selection (DSS)
Display
Distinctive Ringing
End-To-End Signaling
Exclusion
Expert Mode
Extended Stations
External Alerts
Following
Forwarding
Hands-Free Answer on Intercom (HFAI)
Headset Adapter Adjunct
Hold
Inspection
Integrated Solution (IS)
Intercept Treatment With Reorder Tone
Interdigit Timeouts
Last Number Dialed
Leave Word Calling
Line Selection
Line Status and I-Use Indications
Local Display
Manual Signaling2-155
2-158
2-160
2-171
2-172
2-173
2-175
2-178
2-179
2-182
2-185
2-191
2-194
2-199
2-201
2-204
2-207
2-208
2-209
2-212
2-215
2-218
2-220
2-223
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							Message Center-Like Operation (SLAC Only)
Messaging Services
Modem Pooling
Music-On-Hold
Night Service
Night Service Delay Announcements
Off-Premises Stations (OPS)
Out-of-Building Stations
Paging System Access
Park
Personal Dial Code (PDC)
Personal Lines
Pickup
Pooled Facility - Dial Access
Pooled Facility - Direct Access
Power Failure Transfer (PFT)
Program
2-225
2-227
2-230
2-233
2-237
2-240
2-242
2-243
2-244
2-244
2-252
2-254
2-256
2-258
2-260
2-262
2-267
Recall
Remote Access
Remote Administration Interface
Remote Initialization and Maintenance Service (RIMS)2-272
2-273
2-277
2-278
Repertory Dialing
Send All Calls
Speaker2-279
2-281
2-284
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							Speakerphone Adjunct
Speed Dialing
STARLAN NETWORK Access
Station Hunting
Station Message Detail Recording (SMDR)
Station-To-Station Message Waiting
System Administration
System Maintenance
Tandem Trunking
Test
Third-Party Call Setup
Tie Trunks
Touch-Tone and Dial Pulse Services
Transfer
Transfer To Data
Trunk Groups
Trunk-To-Trunk Transfer
User Changeable Options
Virtual Facilities
AUDIX Voice Power System2-285
2-291
2-294
2-302
2-304
2-317
2-318
2-328
2-330
2-332
2-333
2-337
2-340
2-341
2-344
2-346
2-349
2-350
2-356
2-361
-v- 
						

							Figures
Figure 2-1.
Figure 2-2.
Figure 2-3.
Figure 2-4.
Figure 2-5.
Figure 2-6.
Figure 2-7.
Figure 2-8.
Figure 2-9.
Figure 2-10.
Figure 2-11.
Figure 2-12.
Figure 2-13.
Figure 2-14.
Figure 2-15.
Figure 2-16.
Figure 2-17.
Figure 2-18.
Figure 2-19.
Figure 2-20.
Figure 2-21.
Figure 2-22.
Figure 2-23.
Figure 2-24.
Figure 2-25.Typical Direct Trunk Attendant Console Position2-19
Direct Trunk Attendant Console Connections                                2-23
Typical Switched Loop Attendant Console Position
2-24
Buttons and Display of BIS-34D                                                                             2-30
Switched Loop Attendant Console Connections                                               2-33
Model 23A1 Attendant Direct Extension Selector Console                                         2-35
Attendant Direct Extension Selector Console Connections                                  2-38
Automatic Route Selection Flow Chart                                    2-64
Automatic Route Selection Routing Pattern
           2-66
Typical Bridging Arrangement
 2-67
Call Accounting System-On-Premises Direct Connections
(Sharing Same AC Outlet)
 2-79
Call Accounting System-On-Premises Direct Connections
(Greater Than 50 Feet From System Cabinet or Not Sharing
Same AC Outlet)
2-80
Communications Access Manager Architecture                                                   2-102
Direct DS1 Connection Between Adjacent System 25 Cabinets                             2-124
Direct DS1 Connection Between System 25 Cabinets (Located
1310 Feet Apart, Maximum)
2-125
System 25 Connection to DS1 Facility Located 4310 Feet
(Maximum) Away
2-125
System 25 Connection to DS1 Facility Located 4311 Feet or More
Away
 2-126
System 25 Connection to DS1 Facility (Off-Premises Cabling)                              2-126
System 25 Connection to DS1 Facility (Non-Metallic Transmission
Interface)
2-127
System 25 Connection to DS1 551 CSU2-127
Asynchronous Data Unit Interface Signals 2-130
Dictation System Connections (FCC Registered)                                       2-144
Digital Tape Unit
 2-145
Digital Tape Unit-On-Premises Direct Connections (Sharing
Same AC Outlet)
2-146
Delay Announcement Equipment Connections (FCC Registered)                          2-151
-vi-
November 1995 
						

							Figure 2-26.
Figure 2-27.
Figure 2-28.
Figure 2-29.
Figure 2-30.
Figure 2-31.
Figure 2-32.
Figure 2-33.
Figure 2-34.
Figure 2-35.
Figure 2-36.
Figure 2-37.
Figure 2-38.
Figure 2-39.
Figure 2-40.
Figure 2-41.
Figure 2-42.
Figure 2-43.
Figure 2-44.
Figure 2-45.
Figure 2-46.
Figure 2-47.
Figure 2-48.
Figure 2-49.
Figure 2-50.
Figure 2-51.External Alert Connections                                          
Supplemental Alert Adapter Connections                       
Stages of Call Forwarding                            
500A/502B Headset Adapter                       
Typical Headset Adapter to 7300H Series Voice Terminal
Connections Not Requiring Auxiliary Power                            
Typical Headset Adapter to 7300H Series Voice Terminal
Connections Requiring Auxiliary Power                     
Typical Headset Adapter Connections For 12-Button MET Sets      
Music-On-Hold Equipment Connections (FCC Registered)      
Music-On-Hold Equipment Connections (Non-Registered)      
Delay Announcement Equipment Connections (FCC Registered)    
Paging Equipment Connections Using CO Trunk Ports (FCC
Registered)                                                               
Paging Equipment Connection to TN763 CP Using 278A Adapter 
10B Emergency Transfer Unit (ETU)                     
Emergency Transfer Unit Connections                      
Multiple ETU Arrangements                       
Speakerphone Adjuncts                                
Speakerphone Connections For 7300H Series Multiline Voice
Terminals (Except 34-Button Sets)                                       
Speakerphone Connections For 34-Button Voice Terminals      
Speakerphone Connections For 12-Button MET Sets        
STARLAN NETWORK and System 25 Configuration        
STARLAN NETWORK Connection to System 25 (With 2500
Single-Line Telephone)                                         
STARLAN NETWORK Connection to System 25 (With ATL-Type
Telephone)                                                                               
Typical SMDR Call Detail Report                                                                          
SMDR Call Record Format                                                    
SMDR Call Record Header Format                                         
SMDR Output Equipment—On-Premises Direct Connections
(Sharing Same AC Outlet)                                                               
2-180
2-181
2-185
2-195
2-196
2-197
2-198
2-235
2-236
2-241
2-247
2-248
2-264
2-265
2-266
2-287
2-288
2-289
2-290
2-296
2-300
2-301
2-309
2-310
2-311
2-312
-vii-