GLOSSARY
Delay-Dial Tie Trunk
Digital
Digital
After a request for service (called a seizure) is detected on an
incoming trunk, the system sends a momentary signal followed by a
steady tone over the trunk. This informs the calling party that dialing
can start. This type of trunk allows dialing directly into the system;
that is, the digits are received as they are dialed.
Data Endpoints
In System 25, digital data endpoints include any DTE or DCE with an
RS-232C interface to the switch connected through Asynchronous
Data Units.
Tape Unit (DTU)
The RS-232C
translations.
peripheral DTE used to store and reload system
Direct Extension Selector (DXS) Console
An option at the attendant console that allows an attendant direct
access to voice terminals by pressing a Group Select button and a
D X S b u t t o n .
Direct Group Call (DGC)
An incoming call that arrives on a loop-start, ground-start, or tie
trunk and is routed to a predetermined group of stations (for
example, sales department and service department).
Direct Inward Dialing (DID)
A service whereby the called extension (station) number is
transmitted to a PBX by the central office (CO) and incoming calls
are routed directly to the called station, bypassing the attendant.
D S n
Generally, Digital Signal (DS) level n refers to the logical organization
or division of the bandwith available on T carriers. DSO is a single
64 Kbps channel. Twenty-four DS0 channels combine to form a DS1
channel.
Four DS1 channels combine to form a DS2 channel.
Twenty-eight DS1 channels combine to form a DS3 channel.
G-6
Summary of Contents for Network Adapter 25
Page 1: ...AT T AT T System 25 Installation and Maintenance Manual 555 540 103 B November 1995 ...
Page 18: ...APPENDIX F Administration Error Messages GLOSSARY I N D E X F 1 G 1 I 1 viii ...
Page 31: ...INSTALLATION MOUNTING CENTERS WHEN FLANGES ARE OVERLAPPED Figure 2 2 617A Panel 2 7 ...
Page 33: ...INSTALLATION Z21OA1 ADAPTER Y ADAPTER WP90851 L1 858A ADAPTER Figure 2 3 SIP Adapters 2 9 ...
Page 50: ...INSTALLATION Figure 2 10 Three Cabinet System Front View With Covers Removed 2 26 ...
Page 51: ...INSTALLATION Figure 2 11 Position of Shorting Plugs on CPU Memory Circuit Pack 2 27 ...
Page 72: ...INSTALLATION UPPER ADAPTER MOUNTING CLIP Figure 2 18 Mounting Adapters ...
Page 85: ...INSTALLATION 2 61 ...
Page 92: ...INSTALLATION 2 68 ...
Page 103: ...INSTALLATION Figure 2 32 10B Emergency Transfer Unit 2 78 ...
Page 104: ...INSTALLATION Figure 2 33 Emergency Transfer Unit Connections 2 79 ...
Page 109: ...INSTALLATION Figure 2 35 Attendant Console With DXS Console 2 84 ...
Page 146: ...INSTALLATION 2 119b This page intentionally left blank November 1995 ...
Page 153: ...INSTALLATION This page intentionally left blank 2 124b November 1995 ...
Page 223: ...MAINTENANCE Figure 4 2 Clearing Supply Troubles Sheet 1 of 2 4 47 ...
Page 224: ...MAINTENANCE Figure 4 2 Clearing Power Supply Troubles Sheet 2 of 2 ...
Page 225: ...MAINTENANCE Figure 4 3 Clearing CO Trunk Troubles 4 49 ...
Page 226: ...MAINTENANCE Figure 4 4 Clearing 4 Wire Tie Trunk Troubles Sheet 1 of 4 4 50 ...
Page 227: ...MAINTENANCE Figure 4 4 Clearing 4 Wire Tie Trunk Troubles Sheet 2 of 4 4 51 ...
Page 228: ...MAINTENANCE Figure 4 4 Clearing 4 Wire Tie Trunk Troubles Sheet 3 of 4 4 52 ...
Page 229: ...MAINTENANCE Figure 4 4 Clearing 4 Wire Tie Trunk Troubles Sheet 4 of 4 4 53 ...
Page 231: ...Figure 4 6 Clearing Tie Trunk Troubles Sheet 1 of 5 4 55 ...
Page 232: ...MAINTENANCE 6 7 8 9 10 Figure 4 6 Clearing Tie Trunk Troubles Sheet 2 of 5 4 56 ...
Page 233: ...MAINTENANCE Figure 4 6 Clearing Tie Trunk Troubles Sheet 3 of 5 4 57 ...
Page 234: ...MAINTENANCE Figure 4 6 Clearing Tie Trunk Troubles Sheet 4 of 5 4 58 ...
Page 235: ...MAINTENANCE Figure 4 6 Clearing Tie Trunk Troubles Sheet 5 of 5 4 59 ...
Page 236: ...MAINTENANCE Figure 4 7 Clearing Paging Equipment Troubles ...
Page 250: ...MAINTENANCE Figure 4 9 System Cabinet Backplane Wiring Side Sheet 2 of 2 4 74 ...
Page 251: ...MAINTENANCE Figure 4 10 TDM Signal Designations on Cabinet Backplane 4 75 ...
Page 252: ...MAINTENANCE Figure 4 11 Power Designations on Cabinet Backplane 4 76 ...
Page 263: ...MAINTENANCE Figure 4 12 Clearing Virtual Facilities Troubles Sheet 1 of 3 ...
Page 264: ...MAINTENANCE Figure 4 12 Clearing Virtual Facilities Troubles Sheet 2 of 3 4 87 ...
Page 265: ...MAINTENANCE Figure 4 12 Clearing Virtual Facilities Troubles Sheet 3 of 3 4 88 ...
Page 271: ...MAINTENANCE Figure 4 13 Clearing Switched Loop Attendant Console Troubles Sheet 1 of 5 ...
Page 272: ...MAINTENANCE 4 13 Clearing Switched Loop 2 of 5 Console Troubles Sheet 4 95 ...
Page 273: ...MAINTENANCE Figure 4 13 Clearing Switched 3 of 5 Loop Attendant Console Troubles Sheet 4 96 ...
Page 274: ...MAINTENANCE 4 13 Clearing Switched 4 of 5 Console Troubles 4 97 ...
Page 321: ...APPENDIX E Administration Codes and Data This page is intentionally blank E 2 b ...