Manuals / AT&T / Computer Equipment / Network Router

AT&T 7300 series, 7500 series, 7100 series, 2500 series, 7200 series Figure B-17.Excessive Cascading

Models: 7400 series 2500 series 7200 series 7500 series 7300 series 7100 series

1 348

Download 348 pages 35.19 Kb

Page 233

SYNCHRONIZATION OF DIGITAL FACILITIES

B-25

_______________________________________________________________________________________

_

D

A

. . . . . . . . . . . . . . . . . . . . . . . .

C

B

DIGITAL TRANSMISSION FACILITY

PRIMARY FREQUENCY REFERENCE

. . . . . . . . . . . . . .

SECONDARY (BACKUP) FREQUENCY REFERENCE

Figure B-17.Excessive Cascading

D

A

. . . . . . . . . . . . . . . . . . . . . . . .

C

B

DIGITAL TRANSMISSION FACILITY

PRIMARY FREQUENCY REFERENCE

. . . . . . . . . . . . . .

SECONDARY (BACKUP) FREQUENCY REFERENCE

Figure B-18.Minimized Cascading

Image 233

AT&T 7300 series, 7500 series, 7100 series, 2500 series, 7200 series, 7400 series manual Figure B-17.Excessive Cascading

Contents

Definity Communications System Page Contents Communication System Networking AN Overview Multiplexing Outside the SwitchTandem TIE Trunk Networks Data Connectivity AN Overview Distributed Communications System DCSData Communications Capabilities Special Data FeaturesRelated Documents Synchronization of Digital Facilities Data Communications ConfigurationsIndex Trunking Terms and Capabilities Communications ProtocolsGlossary List of Figures Mpdm DSUFigure B-1 Options for Synchronization Figure B-11 External and Internal Reference Levels BCC List of TablesEIA RS-232D V.28 LEADS/DEFINITIONS EIA RS-232C V.28 LEADS/DEFINITIONSEIA RS-449 V.24 LEADS/DEFINITIONS EIA RS-366 LEADS/DEFINITIONSXvi Contents Document Organization About this DocumentPrerequisite Skills and Knowledge ∙ Glossary ∙ Index PartAT&T HOW to Make Comments about this DocumentXx about this Document Introduction to Connectivity 2INTRODUCTION to Connectivity Digital Transmission Transmission TypesAnalog Transmission Analog-to-Digital Conversion Analog VS. Digital 6TRANSMISSION Types Voice Transmission Entering the SwitchTransmission States 8TRANSMISSION States Digital Switch ⎜ Module Exiting the SwitchCircuit Packs Protocol Layers Data Transmission12TRANSMISSION States Originating Switch Destination Layer 1 Protocols Protocols UsedProtocol States Layer 2 ProtocolsConnectivity Rules ⎜DMI Mode Code16TRANSMISSION States Types of Multiplexing Multiplexed CommunicationFrequency-Division Multiplexing Time-Division MultiplexingMultiplexing Over DS1 Facilities Statistical MultiplexingZero Code Suppression ZCS Line Coding Line CodingAlternating Mark Inversion B8ZS Line Coding Restricted ⎜ Unrestricted Signal Inversion⎜ DMI 7Data-Module Capabilities Part 2 Framing D4 FramingESF Framing SignalingD4 Framing Robbed-Bit Signaling ⎜ Channels 24th Channel ⎜ 24th Channel 24th-Channel SignalingESF ⎜ Frame No⎜ Isdn PRI Trunk Types/Destinations ⎜ Signaling Types⎜ DMI-BOS Multiplexing onto T1 Trunks Multiplexing Outside the SwitchCDM CEM Host Digital DMI PBX Altering Channel Assignments on T1 Trunks Compressing the SignalGetting the Signal Ready for the Central Ofﬁce Microwave System T1 Trunk Capacity Multiplexing with MicrowaveDR23N DR18M DR18W DR23W Demultiplexing10.Possible Multiplexed Connections Statistical Multiplexing Local Exchange Trunks TrunkingApplication Tie Trunks Auxiliary Trunks Special-Access TrunksMiscellaneous Trunks Release Link Trunks RLTsHost-Access Trunks Remote Access TrunksAdvanced Private Line Termination Aplt Trunks ConnectivitySignaling Types Administration OptionsSystem 85/G2 Administration Trunk Type Signaling ProtocolsComm Type System 75/G1 AdministrationGroup Type DS1 OptionsTrunk Tables Interface CircuitTrunking 44TRUNKING 11.Generic 1 and Generic 2 Digital Trunks Voice BCC 46TRUNKING Trunking 48TRUNKING Trunking 50TRUNKING Trunking 52TRUNKING Communication System Networking AN Overview Types of Networks Network Evolution PEC Software ⎜ Network Type S75/G1 S85/G2 PackageDCS Software CapabilitiesSystem 75 and Generic 1 UDP Package System 75 and Generic 1 PNA Package DIMENSION, System 85, and Generic 2 Multipremises PackageNetwork Call Processing Distributed Communications SystemRouting the Call Internal Dial PlanUniform Numbering DAC + EXT To ARS Auxiliary Call Information Selecting a Routing Pattern Automatic Alternate Routing∙ RNX Selecting a Trunk Group ∙ Where the trunk group appears in the list of preferences∙ The FRL of the call Modifying the DigitsAnalyzing the Dialed Number Automatic Route SelectionCommunication System Networking AN Overview To AAR Selecting the Routing Pattern Private Network Trunks Network AdministrationNetworking Feature Parameters ⎜ Maap ⎜ Vmaap System Definity Feature PBX 20COMMUNICATION System Networking AN Overview Interactions with Other Networks Tandem TIE Trunk Networks2TANDEM TIE Trunk Networks Attendant Lines ⎜ Main Satellite ⎜ Trunks Main-Satellite Conﬁguration MS/T ConfigurationsMain-Tributary Conﬁguration MS/T Features Networking Package Multipremises with ETA Main Networking Package PNA, ETN Routing Outgoing Calls Routing Incoming CallsEngineering Considerations Other Routing CapabilitiesInteractions Page ETN Configurations ETN Trunks Page Access and Bypass Access Tie Trunks Uniform Numbering Plan FeaturesOff-Net Trunks Attendant ETN Interactions with Other Networks Extension Number Portability Clusters Software-Deﬁned Network Call Routing SDN to ETN Call Routing ETN to SDN Release Link Trunk Networks CAS and ACD Automatic Call Distribution Centralized Attendant ServiceMain-Satellite/Tributary Networks Distributed Communications System ClustersDistributed Communications System DCS DCS Links Switch Node CapacityDCS Clusters Switch Physical Links ⎜Logical Channels/Link Signaling LinksSignaling Link Speed Signaling Link ProtocolTransmission Media Direct Link DCS Connections Linkage Design Distributed Communications System DCS Equipment Distance Limitation DCS Signaling Link ConnectionsMTDM/MPDM System 75 or Generic 1 G1 to System 75 or G1System 75/G1 Signaling Channel DCP System 85 or Generic 2 G2 to System 85 or G2 MtdmModem System 75 or Generic 1 G1 to System 85 or Generic 2 G2 RS232C to RS449 Conversion Dciu Transparent Features Dimension Signaling LinksTransparent Attendant Features Attendant Call Waiting⎜ ACA Attendant Control of Trunk Group AccessAlphanumeric Display Automatic Circuit AssuranceTrunk Group Busy/Warning Indicators Class-of-Service/Restriction DisplayBusy Veriﬁcation of Terminal Lines Calling Number DisplayAutomatic Callback on Busy or No Answer Transparent Voice Terminal FeaturesAlerting-Distinctive Ringing Call Forwarding Call Coverage ToneCall Waiting Leave Word Calling LWC Without APCall Transfer/Conference Audio Information Exchange Audix Features Transparency20.AUDIX in a DCS Network Definity PBX ⎜ Feature 22DISTRIBUTED Communications System DCS Distributed Communications System, Issue 3 Administration ConsiderationsDimension PBX Data Connectivity AN Overview Communications Protocols Data Communications VariablesDigital PBX Public Switched Network Pooled Modem Synchronous vs. Asynchronous Analog vs. DigitalSimplex vs. Half-Duplex vs. Full-Duplex ∙ ∙ ∙Transmission Speed Parallel vs. SerialType of Communications Channel Creating Switch Packet vs. Circuit SwitchesChannel Assignment Dial-up vs. Dedicated Connections Channel Information Bearer vs. Signaling ChannelsTransmission Mode Changes and Modem Pools Terminal Dialing Special Data FeaturesData Call Setup From a Voice Terminal ⎜Data Services FeaturesComputer Dialing Data Hot LineData Privacy Data ProtectionData Restriction Data Only Off-Premises ExtensionOff-Premises Data-Only Extension Conﬁgurations Data Communications Capabilities 2DATA Communications Capabilities Protocol Converters DTE ConnectionsDTE Compatibility PC/PBX or PC/ISDN Terminal EmulatorsVoice Terminal Adjunct Data Modules DCE PossibilitiesData Modules Standalone Data Modules Data Module CharacteristicsADUs ModemsDTE Connections Dtdm PC/PBX ⎜ PC/PBXADM PC/ISDNModem Pooling Connections DCP TIP-RING 12DTE Connections Data Module LAN Protocol Local Area Network ConnectionsLAN Topology Advantages of a Communications System in a LAN Environment LAN ConnectorsLAN Transmission Media LAN Type Operating Gateway PC Access to/from LANs That Use Other Operating SystemsLAN System SoftwareLocal Area Network Connections Remote PC X.25 Router ISN CommunicationCommunication Between the LAN and Other Networks SNA Gateway Type Operating CommunicationsSystem Package 12.LAN/SNA Connectivity Communication System as a LAN BackupAPS Access Accunet Packet ServicePublic and Private Data Network Connections Public Data NetworksSDS and Sddn Applications Circuit-Switched Public Data NetworksPublic and Private Data Network Connections MPDM/M1 Public and Private Data Network Connections DTE Mpdm Private Connections Through Accunet T1.5 and T45 Private Data NetworksTerrestrial Private Data Network Links MPDM/M1* AMI 28PUBLIC and Private Data Network Connections ⎜AMI Satellite Private Data Network Links Integrated Telemarketing Gateway Telemarketing Host ConnectionsIsdn Gateway 22.Telemarketing Gateway Conﬁguration For further details, see 34TELEMARKETING Host Connections Data Network Administration 36DATA Network Administration Data Communications Configurations DSC and PSC Connections DSC 4DATA Communications Configurations SNA Node Connections Video Teleconferencing Connections Through Public or Private Data NetworksFile Transfers FAX Transmittal Image Processing8DATA Communications Configurations General Related DocumentsOperation Reference2RELATED Documents Related Documents Administration DimensionSystem 75 and Generic 6RELATED Documents System 85 and Generic ServiceSales 8RELATED Documents Sales 10RELATED Documents Need for Synchronization Synchronization of Digital FacilitiesFigure B-1.Options for Synchronization Synchronization Hierarchy 4SYNCHRONIZATION of Digital Facilities Synchronization of Digital Facilities ∙ DDS System 85 and Generic 2 Synchronization Architecture Figure B-3.Stratum Levels for the Synchronization HierarchyPage Primary ⎜ Indicators Primary Secondary Reference Indicators ⎜ ReferenceRED YEL Good LOS Misf ⎜ Blue REDSystem 75 and Generic 1 Synchronization Architecture System 75 and Generic 1 Synchronization Software Operation Figure B-6.Tone-Clock Synchronizer Nonduplicated, GenericCriteria for Switching Back to the Primary Reference Criteria for Switching to the Secondary ReferenceExternal Synchronization Clock CROSS-CONNECT B25A Cable Output Figure B-9.External-Clock Interface Network Synchronization and Engineering Selecting a Timing Source for the SwitchRule Internal Reference Selection RulesExample for Rule Figure B-13.Proper Use of Backup Facilities Page Figure B-15.Optimal Diverse Routing Figure B-16.Less Than Optimal Diverse Routing Figure B-17.Excessive Cascading Figure B-19.Excessive Synchronization from One Node Rules 2 Through External-Reference Selection RulesFact Availability of Synchronization SourcesMisconception Conclusions on Synchronization Line-Only Mode DS1/DMI-BOS ANN11 or TN767USE of Generic 2 AS a System Clock Reference ISDN-PRI Trunk FacilitiesDMI-MOS ANN35 or TN767 with TN555 Line+Trunk Mode DS1/DMI-BOS ANN35 or TN767 with TN555USE of Generic 1 AS a System Clock Reference Trunk-Mode ISDN-PRI TN767Trunk-Mode DS1/DMI-MOS TN767 Line-Only Mode DS1/DMI-BOS TN767Trunk-Mode Interface ISDN-PRI + Robbed Bit TN767 32SYNCHRONIZATION of Digital Facilities Address Signaling Wire Tie TrunkTrunking Terms and Capabilities Frequently Used TermsAPLT-Advanced Private Line Termination Alerting SignalsAuto or Automatic-incoming Auto or Automatic-outgoingCX Signaling or Composite Signaling Ccsa or Common Control Switching ArrangementCustomer Provided Access Cut-Through Mode of OperationDelay-Dial Incoming Delay-DialDelay-Dial Outgoing Delay-Dial Start-Dial DdsdDesigned Trunks Derived E&M Lead SignalingDial Repeating Tie Trunk Dial-PulseEpscs or Enhanced Private Switched Communications Service Direct AccessLead Signaling or Ear & Mouth Signaling Standard or Type 1A and Type I compatible or Type 1BFX or Foreign Exchange ETN Trunking FacilitiesGlare Detection Glare ResolutionGlare High-Usage Trunk Group Ground StartImmediate Start Immediate Start IncomingIntermediate High-Usage Trunk Group Interdigit Time-outIntermachine Trunk IMT Intertandem TrunkParty Test Signal Out-of-Band SignalingMain PBX Main-Satellite TrunksSF or Single Frequency signaling Reverse BatterySenderized Mode of Operation Signal ConverterSpecial Access Connections Signaling TypeStop-Go Signaling Supervisory SignalingTrunk Type or trunk group type Touch-Tone SignalingType of Dialing Type of OutpulsingWink-Start Outgoing Wats Wide Area Telephone Service TrunkWink-Start Incoming Suggestions and Helpful Hints Signaling Types Trunking Characteristics TableSupervision Signaling Tion Generic Switch aSystem 85, or Dimension PBX ⎜GROUP/CALL TypeGROUP/CALL Type Switch BIN/DID DOD23/FX-DOD OUT GROUP/CALL Type Signaling 28/WATS-DOD OUT 26/WATS27/WATS OUT ⎜⎜ E&M 35/TIE ESS 5ESS ⎜OTHER ⎜ LS ⎜ RB ⎜ System 85, or ⎜DIMENSION PBX ⎜ Main Satellite ⎜57/CAS RLT-OUTGOING From Branch ⎜66/CAS RLT-INCOMING⎜DIAL-TONE with Line Side 104/HOST Access Digital Data ⎜DATA Module Side 103/HOST AccessAnalog Data Modem Side Trunk SideOther 32TRUNKING Terms and Capabilities Communications Protocols Physical Layer OSI ModelData-Link Layer Network LayerPage Figure D-1.OSI Reference Model Presentation Layer Session LayerApplication Layer Standard ProtocolsTable D-1.Some Ccitt Digital Standards Ccitt X.26 RS-423A FED-STD Table D-2.Some Ccitt Analog StandardsTable D-2.Some Ccitt Analog Standards CCITT-ISO Other Common StandardsEIA AT&T ProtocolsData Modes Data Mode CapabilitiesDigital Multiplexed Interface Description ApplicationsControl Data DCP DS1/DMI/BOS Channel 14COMMUNICATIONS Protocols Communications Protocols Flag Digital Communications Protocol Or multipoint BX.25 Communication Pathways and Endpoints Sldh Message, Packet, and FrameLead Definitions SCB SCFSBA SBBCH/CI RL/CGSTA SDARDA RSAACR DPRCRQ PNDBBB BBADDA DDB⎜ PIN 8LEAD Definitions Networking FEATURES--AVAILABILITY Matrix ⎜⎜ R1 Networking FEATURES--AVAILABILITY Matrix Contd ⎜ NA ⎜ Uniform Numbering ⎜ Plan Note 6NETWORKING FEATURES--AVAILABILITY Matrix Abbreviations CSM CRCCSU DACETN ETAFAX FEPMS/T MpdmMtdm NCPSMT SDNSNA TehoAB-6ABBREVIATIONS ACU GlossaryADM AVDADS Audix Standalone Also high-volume tandemAutomatic Alternate Routing AARBipolar signal Service BccosBit-oriented signaling Message-oriented signalingCPU BSCCcitt COR CcisCOS CPESee data communications equipment See network channel-terminating equipmentDCP DCS Dciu linkDCS cluster DCS node See bit rateDDD DDCSee digital telephone DMI-MOS DCS DMI-BOSDMI/MOS DS1ESS electronic switching Error-free secondCommunications systems and switch Framing format Extended trunk accessBX.25 DCIU/PI Hdlc See basic rate interface See primary rate interface Keyboard dialing Kilo bits per second kbpsLAN Lapd Local area network LAN Listed directory numberAlso wide area network Local exchange companyNAU NctePAD PDM PVCRemote access trunk 921, and signaling system numberRobbed-bit signaling Protocol converter PCSdlc TDM UNP UCDTelecommunications Service Service Wats trunkWats Wide Area TelecommunicationsIndex IN-2 Index Bypass access trunk 1-37,4-7,4-8,5-1,5-4,C-2ARS 2-4,2-7,2-8,2-14plan Logical 6-3,D-19restricted 1-20unrestrictedCRC 1-25CSMA/CD 8-13CSU Dial access code 2-2,2-5,2-10,2-13,2-17,3-1,4-4Channel bank 1-9,1-10,1-29,1-30,B-20frame DAC 2-2,2-5,2-10,2-13,2-17,3-1,4-4,4-7,4-8,4-9,6-236digitizer Mode 1-15,1-16,1-42,2-13,9-1MOSDMI 1-14, D-11 DS1-ContdESF 1-24, 1-27 D4 1-24, 1-27FRL 2-10, 2-13 Gateway 7-2LOS B-9,B-13 LWC 6-18,6-21,6-24 Statistical 1-17,1-18,1-34DCS 1-36,2-3,5-14 ETN 1-36,2-2,2-8,3-1,4-1,5-1,6-1PCM 1-5,1-7,1-14,1-18,B-1 PAD 7-2,8-21Analog 1-7,9-2trunk DS1 1-13,1-16,1-18Physical layer 1-11,1-15,D-2,D-9 RS-232C1-13,D-9PRI 1-13, D-11 RS-232C1-13,6-3Subnet trunking 2-11, 2-14, 4-9 RNX 2-101-39, C-3, C-5, C-6 Intelligent main 2-4, 4-4, 4-7T1 carrier 1-6,1-18,1-32 Analog 1-3,7-2,7-4 Bypass access 1-37,4-7,4-8,5-1,5-4TCM 2-11,6-23 ﬁnal 5-2,C-9Analog 1-9 Uniform dial plan 2-5, 2-8, 2-9Uniform numbering 2-8, 5-1, 5-5 Auxiliary 1-10, 1-35IN-12 Index