AT&T DEFINITY 2500 series Installation and maintenance instructions

AT&T 555-025-201
DEFINITY®Communications System
Network and Data Connectivity

CONTENTS
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AABBOOUUTT TTHHIISS DDOOCCUUMMEENNTT xxvviiii
PREREQUISITE SKILLS AND KNOWLEDGE xvii
DOCUMENTORGANIZATION xvii
HOW TO MAKE COMMENTS ABOUT THIS DOCUMENT xix
11.. IINNTTRROODDUUCCTTIIOONN TTOO CCOONNNNEECCTTIIVVIITTYY 11--11
TRANSMISSION TYPES 1-3
ANALOG TRANSMISSION 1-3
DIGITAL TRANSMISSION 1-3
ANALOG VS. DIGITAL 1-5
TRANSMISSION STATES 1-7
VOICE TRANSMISSION 1-7
Entering the Switch 1-7
Exiting the Switch 1-9
DATA TRANSMISSION 1-11
Protocol Layers 1-11
Protocols Used 1-13
Protocol States 1-14
Connectivity Rules 1-15
MULTIPLEXED COMMUNICATION 1-17
TYPES OF MULTIPLEXING 1-17
Frequency-Division Multiplexing 1-17
Time-Division Multiplexing 1-17
Statistical Multiplexing 1-18
MULTIPLEXING OVER DS1 FACILITIES 1-18
Line Coding 1-19
Signal Inversion 1-21
Framing 1-24
Signaling 1-25
iii

iv CONTENTS
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MULTIPLEXING OUTSIDE THE SWITCH 1-29
Multiplexing onto T1 Trunks 1-29
Compressing the Signal 1-31
Altering Channel Assignments on T1 Trunks 1-31
Getting the Signal Ready for the Central Office 1-31
Changing the Transmission Medium from Metallic to Fiber-Optic 1-32
Multiplexing with Microwave 1-32
Demultiplexing 1-32
STATISTICAL MULTIPLEXING 1-34
TRUNKING 1-35
APPLICATION 1-35
Local Exchange Trunks 1-35
Tie Trunks 1-36
Special-Access Trunks 1-37
Auxiliary Trunks 1-37
Miscellaneous Trunks 1-37
CONNECTIVITY 1-38
ADMINISTRATION OPTIONS 1-39
System 85/G2 Administration 1-39
System 75/G1 Administration 1-41
DS1 Options 1-41
INTERFACE CIRCUIT 1-42
TRUNK TABLES 1-42
22.. CCOOMMMMUUNNIICCAATTIIOONN SSYYSSTTEEMM NNEETTWWOORRKKIINNGG —— AANN OOVVEERRVVIIEEWW 22--11
TYPES OF NETWORKS 2-2
NETWORK EVOLUTION 2-3
SOFTWARE CAPABILITIES 2-4
Basic Networking Software 2-4
Main-Satellite/Tributary Software — The UDP and Multipremises Packages 2-5
Electronic Tandem Network Software — The PNA and ETN (Standard Network) Packages 2-6
Distributed Communications System 2-7
NETWORK CALL PROCESSING 2-7

CONTENTS v
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Internal Dial Plan 2-8
Auxiliary Call Information 2-10
Automatic Alternate Routing 2-11
Automatic Route Selection 2-14
NETWORK ADMINISTRATION 2-17
PRIVATE NETWORK TRUNKS 2-17
NETWORKING FEATURE PARAMETERS 2-17
33.. TTAANNDDEEMM TTIIEE TTRRUUNNKK NNEETTWWOORRKKSS 33--11
INTERACTIONS WITH OTHER NETWORKS 3-1
44.. MMAAIINN--SSAATTEELLLLIITTEE//TTRRIIBBUUTTAARRYY ((MMSS//TT)) NNEETTWWOORRKKSS TTHHRROOUUGGHH TTHHEE UUDDPP OORR
MMUULLTTIIPPRREEMMIISSEESS PPAACCKKAAGGEESS 44--11
MS/T CONFIGURATIONS 4-2
Main-Satellite Configuration 4-2
Main-Tributary Configuration 4-3
MS/T FEATURES 4-4
Routing Incoming Calls 4-7
Routing Outgoing Calls 4-7
Other Routing Capabilities 4-8
ENGINEERING CONSIDERATIONS 4-8
INTERACTIONS 4-9
55.. EELLEECCTTRROONNIICC TTAANNDDEEMM NNEETTWWOORRKK ((EETTNN)) TTHHRROOUUGGHH TTHHEE EETTNN AANNDD PPNNAA
PPAACCKKAAGGEESS 55--11
ETN CONFIGURATIONS 5-1
ETN TRUNKS 5-2
Access and Bypass Access Tie Trunks 5-4
Off-Net Trunks 5-5
FEATURES 5-5
Uniform Numbering Plan 5-5
Automatic Alternate Routing 5-7

vi CONTENTS
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Automatic Route Selection 5-7
ETN INTERACTIONS WITH OTHER NETWORKS 5-7
Extension Number Portability Clusters 5-8
Software-Defined Network 5-9
Release Link Trunk Networks — CAS and ACD 5-12
Distributed Communications System Clusters 5-14
Main-Satellite/Tributary Networks 5-14
ENGINEERING CONSIDERATIONS 5-14
66.. DDIISSTTRRIIBBUUTTEEDD CCOOMMMMUUNNIICCAATTIIOONNSS SSYYSSTTEEMM ((DDCCSS)) 66--11
DCS CLUSTERS 6-2
DCS LINKS 6-2
Tie Trunks 6-3
Signaling Links 6-3
DCS SIGNALING LINK CONNECTIONS 6-8
System 75 or Generic 1 (G1) to System 75 or G1 6-8
System 85 or Generic 2 (G2) to System 85 or G2 6-10
System 75 or Generic 1 (G1) to System 85 or Generic 2 (G2) 6-12
DIMENSION Signaling Links 6-14
TRANSPARENT FEATURES 6-14
Transparent Attendant Features 6-14
Transparent Voice Terminal Features 6-17
Audio Information Exchange (AUDIX) Features Transparency 6-19
ENGINEERING CONSIDERATIONS 6-21
ADMINISTRATIONCONSIDERATIONS 6-23
77.. DDAATTAA CCOONNNNEECCTTIIVVIITTYY —— AANN OOVVEERRVVIIEEWW 77--11
DATA COMMUNICATIONS VARIABLES 7-2
Communications Protocols 7-2
Analog vs. Digital 7-4
Synchronous vs. Asynchronous 7-4
Simplex vs. Half-Duplex vs. Full-Duplex 7-5

CONTENTS vii
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Parallel vs. Serial 7-6
Transmission Speed 7-6
Type of Communications Channel 7-7
SPECIAL DATA FEATURES 7-9
Terminal Dialing 7-9
Data Call Setup From a Voice Terminal 7-10
Computer Dialing 7-10
Data Hot Line 7-10
Data Protection 7-11
Data Privacy 7-11
Data Restriction 7-11
Data Only Off-Premises Extension 7-11
88.. DDAATTAA CCOOMMMMUUNNIICCAATTIIOONNSS CCAAPPAABBIILLIITTIIEESS 88--11
DTE CONNECTIONS 8-3
DTE COMPATIBILITY 8-3
Protocol Converters 8-3
Terminal Emulators 8-4
PC/PBX or PC/ISDN 8-4
DCE POSSIBILITIES 8-5
Data Modules 8-5
ADUs 8-6
Modems 8-6
DATA MODULE CHARACTERISTICS 8-6
MODEM POOLING CONNECTIONS 8-10
LOCAL AREA NETWORK CONNECTIONS 8-13
LAN TOPOLOGY 8-13
LAN PROTOCOL 8-13
LAN TRANSMISSION MEDIA 8-14
LAN CONNECTORS 8-14
ADVANTAGES OF A COMMUNICATIONS SYSTEM IN A LAN ENVIRONMENT 8-14
Communication Between the LAN and Outside DTEs 8-15
Communication Between the LAN and Other Networks 8-18

viii CONTENTS
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The Communication System as a LAN Backup 8-20
PUBLIC AND PRIVATE DATA NETWORK CONNECTIONS 8-21
PUBLIC DATA NETWORKS 8-21
Packet-Switched Public Data Networks 8-21
Circuit-Switched Public Data Networks 8-22
PRIVATE DATA NETWORKS 8-26
Terrestrial Private Data Network Links 8-26
Satellite Private Data Network Links 8-30
TELEMARKETING HOST CONNECTIONS 8-31
THE ISDN GATEWAY 8-31
THE INTEGRATED TELEMARKETING GATEWAY 8-31
DATA NETWORK ADMINISTRATION 8-35
99.. DDAATTAA CCOOMMMMUUNNIICCAATTIIOONNSS CCOONNFFIIGGUURRAATTIIOONNSS 99--11
DSC AND PSC CONNECTIONS 9-2
SNA NODE CONNECTIONS 9-5
CONNECTIONS THROUGH PUBLIC OR PRIVATE DATA NETWORKS 9-6
File Transfers 9-6
Video Teleconferencing 9-6
Image Processing 9-7
FAX Transmittal 9-7
AA.. RREELLAATTEEDD DDOOCCUUMMEENNTTSS AA--11
BB.. SSYYNNCCHHRROONNIIZZAATTIIOONN OOFF DDIIGGIITTAALL FFAACCIILLIITTIIEESS BB--11
THE NEED FOR SYNCHRONIZATION B-1
SYNCHRONIZATION HIERARCHY B-3
CHANGES TO THE SCS SOFTWARE MADE AVAILABLE VIA SOFTWARE PATCHES B-11
NETWORK SYNCHRONIZATION AND ENGINEERING B-18
AVAILABILITY OF SYNCHRONIZATION SOURCES B-28
CONCLUSIONS ON SYNCHRONIZATION B-29

CONTENTS ix
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USE OF GENERIC 2 AS A SYSTEM CLOCK REFERENCE B-29
USE OF GENERIC 1 AS A SYSTEM CLOCK REFERENCE B-30
CC.. TTRRUUNNKKIINNGG TTEERRMMSS AANNDD CCAAPPAABBIILLIITTIIEESS CC--11
DD.. CCOOMMMMUUNNIICCAATTIIOONNSS PPRROOTTOOCCOOLLSS DD--11
OSI MODEL D-2
STANDARD PROTOCOLS D-5
AT&T PROTOCOLS D-10
EE.. LLEEAADD DDEEFFIINNIITTIIOONNSS EE--11
FF.. NNEETTWWOORRKKIINNGG FFEEAATTUURREESS————AAVVAAIILLAABBIILLIITTYY MMAATTRRIIXX FF--11
AABBBBRREEVVIIAATTIIOONNSS AABB--11
GGLLOOSSSSAARRYY GGLL--11
IINNDDEEXX IINN--11

xCONTENTS
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LIST OF FIGURES
Figure 1-1. Analog-to-Digital Conversion 1-4
Figure 1-2. Transmission States for Voice Communication 1-8
Figure 1-3. Transmission States for Data Transmission 1-12
Figure 1-4. Time Slot 1-17
Figure 1-5. Alternating Mark Inversion 1-19
Figure 1-6. Example of B8ZS Line Coding 1-20
Figure 1-7. D4 Framing 1-24
Figure 1-8. The Extended Super Frame 1-26
Figure 1-9. T1 Trunk Multiplexing 1-30
Figure 1-10. Possible Multiplexed Connections 1-33
Figure 1-11. Statistical Multiplexing 1-34
Figure 2-1. Internal Dial Plan Interactions 2-9
Figure 2-2. AAR Processing 2-12
Figure 2-3. ARS Processing 2-15
Figure 4-1. Standalone MS/T Network 4-1
Figure 4-2. MS/T Coordinated Numbering 4-3
Figure 4-3. Dialing Patterns From Tributary or Satellite to Main 4-5
Figure 4-4. Dialing Patterns From Main to Satellite or Tributary 4-5
Figure 4-5. Dialing Patterns From Main to Tandem 4-6
Figure 4-6. Dialing Patterns From Satellite or Tributary to Tandem 4-6
Figure 5-1. Typical 2-Level Hierarchical Electronic Tandem Network (ETN)
Configuration 5-3
Figure 5-2. An Example of Intermachine Tie Trunk Usage (Overflow Routing) 5-4
Figure 5-3. Private Network Uniform Numbering Plan 5-7
Figure 5-4. Extension Number Portability Cluster Using Common RNXs 5-8
Figure 5-5. Feasible ETN/SDN Configuration 5-10
Figure 5-6. Call Flow SDN - to - ETN 5-11
Figure 5-7. Call Flow ETN - to - SDN 5-12
Figure 5-8. Centralized Attendant Service 5-13
Figure 6-1. Distributed Communications System (DCS) Cluster 6-1
Figure 6-2. Internally Connected DCS Signaling Channel Over a DS1 6-4