Introduction to Wide Area Networks

Transcription

1 Contents Introduction to Wide Area Networks Introduction to Wide Area Networks Preface...i Prerequisites...i Key Topics...ii Course Objectives...ii Pedagogical Features...iii Learning Objectives, Unit Summaries, Discussion Questions, and Activities/Exercises...iii Key Terms...iii Supplements...iii Advancing Your Level of Technical Expertise...iv Why Choose WestNet?...iv Introduction... xxi Course Overview...xxii Unit 1 Fundamentals of WANs...1 Classification of Networks...10 LANs Campus Networks...11 MANs...12 WANs Activities i

2 Introduction to Wide Area Networks Telecommunications...17 Development of the Telecommunications Network More Than Just Words Activities Voice Networks...22 Connectivity of the Analog Network Reduction of Trunk Lines Activities Voice Network Technology...28 Analog Technology...28 Early Telephones...30 FDM...30 Duplexing PBXs...34 Activities Lesson 5 PBX Fundamentals...38 PBX Components Trunks...39 Extension Lines Equipment Cabinet Telephones and Attendant Console Administrative Terminal Making a Call on a PBX Call Routing Supplementary PBX Features DID...43 DISA Station Set Features...43 Attendant Console Services Administration and Management Reports...45 CDRs...45 Test Reports Busy-Hour Studies PBX Enhancements...46 Voice Response...46 Voice Recognition Call Following ACD Other Auxiliary Equipment...48 PBX Costs and Requirements Activities ii

3 Contents Lesson 6 PBX Features and Functions...52 Call Accounting Authorization Codes Account Codes...53 Voice Mail Systems Design Factors Unified Messaging Broadcasting...56 Voice Mail Security Automated Attendants CoR Call Pickup Call Park Call Forwarding...59 Call Announcement Call Waiting DAU...59 Activity Lesson 7 Computer Data and the Voice Network...62 Analog and Digital Signals Modems...64 Activities Lesson 8 Digitizing the Voice...67 Analog to Digital...68 Mixing It Up TDM...70 WDM...71 Activities Lesson 9 Integration of Services...74 Ones and Zeros Data Transfer...75 Voice Conversations...75 Activities Elements of the Telecommunications Business...78 The Players IXCs RBOCs/LECs...79 CLECs...79 CAPs...80 Regulated Competition...81 iii

4 Introduction to Wide Area Networks iv An Expanded Role for the FCC LNP...82 Shared Platforms Network Interconnection...82 Unbundled Local Loops...82 Reciprocal Compensation Tariffs Effects of Competition Legal Struggles Price Pressure Slamming...85 Niche Companies...85 Activities Unit 2 WAN Concepts and Components...95 Physical and Logical Circuits Circuits and Virtual Circuits PVCs and SVCs SVC Information Transfer Activities Connecting to WAN Circuits DCE DTE-to-DCE Protocols Layer Upon Layer Activities Connecting to Analog Networks Modem Concepts Internal vs. External Modems UART RS Modem Signals Activities Analog Modems Modem Protocols Modulation FM AM PM Modem Operations Activities

5 Contents Lesson 5 Modem Compatibility Timing is Everything Data Compression and Error Control Modem Compatibility AT&T Compatibility CCITT Compatibility Hayes Compatibility Activities Lesson 6 Connecting to Digital Networks DTE/CSU Interface Smart Jack Subrate Facilities DDS Activities Lesson 7 Microwave Communications Fundamentals of Microwave Communications Microwave Components MUXs Modems Transmitters/Receivers Antenna Equipment Activities Lesson 8 Satellite Communications Linking to a Satellite Satellite Equipment Satellite Frequency Ranges Satellite Characteristics Satellites and Orbits Bandwidth Satellite Protocols Satellite Use Activities Lesson 9 End-to-End Connectivity WAN Applications Activities v

6 Introduction to Wide Area Networks Unit 3 Physical Layer WAN Protocols Summary of Data Rates Point-to-Point Links Various Data Rates and Associated Applications Bandwidth Activities Dial-Up and Leased Lines Dial-Up Connections Leased Lines DDS Activities SW SW56 Service SW56 Operation Activity VSAT VSAT Use Satellite Applications Activities Lesson 5 T-Carriers and E-Carriers T1, FT1, and T T FT T3 and North American Digital Hierarchy Signal Shapes and Codes T1 Signaling Cabling Connectors Applications Circuit Costs Activities Lesson 6 ADSL Fundamentals of ADSL DSLs and Internet Access Why High-Speed Local Loop Is Hot vi

7 Contents Options for Local High-Speed Internet Access Activities Lesson 7 Cable Modems Cable Modem Technology ADSL or Cable Modem? The Subscriber s Perspective Activities Lesson 8 SONET SONET Standard SONET Advantages SONET Protocol Architecture Path Layer Line Layer Section Layer Photonic Layer SONET Multiplexing SONET Frame Format SONET Network Elements Activities Unit 4 Data Link Layer WAN Protocols A Layer Above Data Link Layer Protocols Reliable WAN Networks Activities HDLC HDLC Operation HDLC Protocol Activities SLIP and PPP SLIP CSLIP PPP Activities End-to-End Connectivity Connecting to the Internet Activity vii

8 Introduction to Wide Area Networks viii Unit 5 Higher-Layer WAN Protocols ISDN Concepts IDNs ISDN Services Activities ISDN Protocols Fundamentals of ISDN Protocols Physical Attachment to ISDN Data Link Layer Call Setup, LAPD Network Layer Call Control, I Network Layer Packet-Switching, X ISDN CPE ISDN Reference Points Activities ISDN Implementation ISDN Applications Basic Network Connectivity Internetworking of Remote Offices Dial-on-Demand Remote Networking Network Redundancy and Overflow Activities Frame Relay Concepts What Is Frame Relay? Frame Relay Terms Activities Lesson 5 Frame Relay Protocols Permanent and Virtual Circuits Frame Relay Frame Frame Relay Addressing Interconnecting LANs Using Frame Relay Activities Lesson 6 Frame Relay Implementation Frame Relay Implementation Options Private Frame Relay Public Frame Relay Hybrid Frame Relay

9 Contents End-User Access to Frame Relay Networks Frame Relay vs. Private Line Networking Frame Relay Services Public Frame Relay Services Bandwidth on Demand Conditional Bursting Carrier Choice Frame Relay Network Requirements Activities Lesson 7 X X.25 Services Addressing X.25 Protocols PLP LAPB X.21 and X.21bis PADs PLP Overhead and Performance Limitations Activity Unit 6 WAN Solutions ATM Concepts The Need for ATM ATM Protocols Transfer Modes STM PTM ATM Connection-Oriented Mode Fixed-Length Cells Header Details B-ISDN and ATM AAL ATM Layer Physical Layer Activities ATM Implementation VPs and VCs ATM in Action ATM Communication ATM Over SONET ix

10 Introduction to Wide Area Networks ATM LAN/WAN Solutions ATM Devices Activities ATM Devices Categories of ATM Devices Routers CSU/DSUs NICs Switches Intelligent Hubs ATM Networks Activities Extended Activity SMDS SMDS Operation Switched Multimegabit SNI SMDS Protocols SIP DXI Router Functions DSU Functions Advantages and Disadvantages Activities Lesson 5 IEEE : The Wireless Last Mile The Promise of Broadband Wireless Networks Equipment The Protocol Layers The CS The MAC CPS The Privacy Sublayer The PHY Network Example Activities Lesson 6 Sample Network Role of the Network in the Organization Primary Applications Used by the Organization General Connectivity Strategy x

11 Contents Overall WAN/LAN Topologies Future Growth Plans and Migration Strategies Activities Unit 7 Convergence of Communications Over WAN Technologies Voice Over Alternative Technologies History Market Drivers Voice Over the Internet VoFR Voice Over ATM Market Direction and Trends Activities Fundamental VoIP Network Components Overview of the ITU-T H.323 Standard Version 1: Videophone Version 2: Packet-Based Multimedia Version 3: Under Development Other Standards of the H.323 Family H.323 Network Components Terminals MCUs Gateways Gatekeepers MGCP MGCP Network Components MGCP Call Control Transactions Activities Factors Driving the Demand for Packet Telephony Long-Term Trends Open Standards, Open Market More Bandwidth Carrier Applications Enterprise Applications Voice Rides for Free Transparent Technology Improved Network Management Network Flexibility and Scalability Access to New Applications Activities xi

12 Introduction to Wide Area Networks Private VPNs Private Communications Networks Cost Savings Improved Efficiency Enhanced User Satisfaction Activities Lesson 5 PSTN Remote Access Remote Access Applications Dial-Up Access ISDN Access DSL Access Activities Course Quiz Glossary Index WestNet s Related Titles Notes Overall Course Evaluation Survey xii