Communications System Owner Manual

ManualsBrandsAT&T ManualsNetwork RouterDEFINITY 7400 series

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Table Of Contents

Table of Contents
ABOUT THIS DOCUMENT
- PREREQUISITE SKILLS AND KNOWLEDGE
- DOCUMENT ORGANIZATION
- HOW TO MAKE COMMENTS ABOUT THIS DOCUMENT
1. INTRODUCTION TO CONNECTIVITY
- TRANSMISSION TYPES
- TRANSMISSION STATES
  - VOICE TRANSMISSION
    - Entering the Switch
    - Exiting the Switch
  - DATA TRANSMISSION
- MULTIPLEXED COMMUNICATION
- TRUNKING
2. COMMUNICATION SYSTEM NETWORKING (em AN OVERVIEW
- TYPES OF NETWORKS
- NETWORK EVOLUTION
- SOFTWARE CAPABILITIES
- NETWORK CALL PROCESSING
- NETWORK ADMINISTRATION
- PRIVATE NETWORK TRUNKS
- NETWORKING FEATURE PARAMETERS
3. TANDEM TIE TRUNK NETWORKS
- INTERACTIONS WITH OTHER NETWORKS
4. MAIN-SATELLITE/TRIBUTARY (MS/T) NETWORKS THROUGH THE UDP OR MULTIPREMISES PACKAGES
- MS/T CONFIGURATIONS
  - Main-Satellite Configuration
  - Main-Tributary Configuration
- MS/T FEATURES
- ENGINEERING CONSIDERATIONS
- INTERACTIONS
5. ELECTRONIC TANDEM NETWORK (ETN) THROUGH THE ETN AND PNA PACKAGES
- ETN CONFIGURATIONS
- ETN TRUNKS
  - Access and Bypass Access Tie Trunks
  - Off-Net Trunks
- FEATURES
- ETN INTERACTIONS WITH OTHER NETWORKS
- ENGINEERING CONSIDERATIONS
6. DISTRIBUTED COMMUNICATIONS SYSTEM (DCS)
- DCS CLUSTERS
- DCS LINKS
  - Tie Trunks
  - Signaling Links
- DCS SIGNALING LINK CONNECTIONS
- TRANSPARENT FEATURES
- ENGINEERING CONSIDERATIONS
- ADMINISTRATION CONSIDERATIONS
7. DATA CONNECTIVITY - AN OVERVIEW
- DATA COMMUNICATIONS VARIABLES
- SPECIAL DATA FEATURES
8. DATA COMMUNICATIONS CAPABILITIES
- DTE CONNECTIONS
- LOCAL AREA NETWORK CONNECTIONS
- PUBLIC AND PRIVATE DATA NETWORK CONNECTIONS
  - PUBLIC DATA NETWORKS
    - Packet-Switched Public Data Networks
    - Circuit-Switched Public Data Networks
  - PRIVATE DATA NETWORKS
    - Terrestrial Private Data Network Links
    - Satellite Private Data Network Links
- TELEMARKETING HOST CONNECTIONS
  - THE ISDN GATEWAY
  - THE INTEGRATED TELEMARKETING GATEWAY
- DATA NETWORK ADMINISTRATION
9. DATA COMMUNICATIONS CONFIGURATIONS
- DSC AND PSC CONNECTIONS
- SNA NODE CONNECTIONS
- CONNECTIONS THROUGH PUBLIC OR PRIVATE DATA NETWORKS
A. RELATED DOCUMENTS
B. SYNCHRONIZATION OF DIGITAL FACILITIES
- THE NEED FOR SYNCHRONIZATION
- SYNCHRONIZATION HIERARCHY
- CHANGES TO THE SCS SOFTWARE MADE AVAILABLE VIA SOFTWARE PATCHES
- NETWORK SYNCHRONIZATION AND ENGIINEERING
- AVAILABILITY OF SYNCHRONIZATION SOURCES
- CONCLUSIONS ON SYNCHRONIZATION
- USE OF GENERIC 2 AS A SYSTEM CLOCK REFERENCE
- USE OF GENERIC 1 AS A SYSTEM CLOCK REFERENCE
C. TRUNKING TERMS AND CAPABILITIES
D. COMMUNICATIONS PROTOCOLS
- OSI MODEL
- STANDARD PROTOCOLS
- AT&T PROTOCOLS
E. LEAD DEFINITIONS
F. NETWORKING FEATURES - AVAILABILITY MATRIX
ABBREVIATIONS
GLOSSARY
INDEX

SYNCHRONIZATION OF DIGITAL FACILITIES B-23

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Facility rank ordering is generally based on limited technical and operational information. It is

recommended that facility selections be based on local ﬁeld experience where available.

RULE 4:

Where possible, the routes for all primary and secondary synchronization facilities should be diverse.

EXAMPLE FOR RULE 4

Figure B-15, Optimal Diverse Routing, explains the optimal conﬁguration when rule 4 is used. Figure B-

16, Less Than Optimal Diverse Routing, shows a less than optimal application of rule 4.

SECONDARY (BACKUP) FREQUENCY REFERENCE

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PRIMARY FREQUENCY REFERENCE

DIGITAL TRANSMISSION FACILITY

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Figure B-15. Optimal Diverse Routing

Figure B-16, Less Than Optimal Diverse Routing, shows node C deriving both primary and secondary

timing from node D, via the two separate T1 facilities. If node D should fail, node C would no longer

receive timing that is traceable to node A. Here, node C would lose synchronization and begin to introduce

slips into the network.