contentsstore.westnetlearning.com/mkt/catalog/toc/pcn_toc.pdfcontents iii lesson 4 network...

Contents

Preface ........................................................................... xxvii

Prerequisites .................................................................................xxviiWho Should Study This Course? .................................................xxviiKey Topics ...................................................................................xxviiiCourse Objectives ........................................................................xxviiiCTP Exam Information .................................................................xxix

Exam Objectives .....................................................................xxixHow Do I Use This Course? ......................................................... xxxv

Real-World Scenarios ...........................................................xxxviPedagogy ..............................................................................xxxviKey Terms .............................................................................xxxvi

Resources Available in Instructor-Led Settings ...........................xxxviWhy Choose WestNet? ..............................................................xxxvii

Introduction .................................................................. xxxix

Course Overview .........................................................................xxxix

Module 1Physical Communication Infrastructure ..............................1

Lesson 1Communication and Signals ..................................................3

Analog and Digital Transmission .......................................................4Analog Transmission ...................................................................4Modulation ..................................................................................5Analog Bandwidth ......................................................................6Digital (Baseband) Transmission .................................................6Digital Signals Over Analog Links ...............................................7Digital Bandwidth .......................................................................8

One-Way or Two-Way Transmission .................................................8Signal Timing ..............................................................................8

Different Signals, Different Media .....................................................9Communication Standards ................................................................9

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Principles of Converged Networks: VoIP, Voice, and Data

Physical Signaling Standards Organizations .............................10ITU ......................................................................................10IEEE .....................................................................................10EIA and TIA ........................................................................11ANSI ....................................................................................11ISO ......................................................................................11AT&T and Bell Labs ............................................................12

Internet Standards Organizations .............................................12NSF .....................................................................................12IETF .....................................................................................13ISOC ...................................................................................14IAB ......................................................................................15IESG ....................................................................................15IRTF ....................................................................................15IANA and ICANN ...............................................................16

IP Address Assignment ..............................................................18W3C ....................................................................................18

Review Questions .............................................................................19

Lesson 2Internal Computer Components: CPU, I/O, Memory, and NICs ..............................................................23

CPU ..................................................................................................23I/O ....................................................................................................24

Video Display ............................................................................26Memory ............................................................................................26NICs ..................................................................................................27

Different Networks, Different NICs ..........................................27Each NIC is Unique ...................................................................28NIC Connectivity in a PC .........................................................28Summary of NIC Characteristics ...............................................29


Lesson 3Software ..............................................................................32

Programs and Processes ....................................................................32Master/Slave ..............................................................................33Peer-to-Peer ...............................................................................33Client/Server ..............................................................................33

Client/Server Advantages ...................................................34Independent Computing Architecture ..............................34

Hosts ..........................................................................................34Application Software ........................................................................34Operating Systems ............................................................................35Device Drivers ..................................................................................35Network Management Software .......................................................36Review Questions .............................................................................37

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Contents

Lesson 4Network Topologies ............................................................39

Types of Networks ............................................................................39Bus Topology ....................................................................................40Star Topology ...................................................................................41Ring Topologies ................................................................................42

Ring ...........................................................................................42Star Ring ....................................................................................43

Wide Area Topologies ......................................................................45Full Mesh ...................................................................................45Partial Mesh ...............................................................................46Network Cloud ..........................................................................46

Advantages of Cloud Networks ..........................................47Hybrid Topologies ............................................................................48Logical and Physical Topologies ......................................................49

Physical Star, Logical Bus ..........................................................49Physical Star, Logical Ring ........................................................50


Lesson 5Copper Cable ......................................................................54

Transmission Basics ..........................................................................54Voltage Buildup .........................................................................55Timing Synchronization ...........................................................56Signal Strength ..........................................................................56

Transmission Problems and Characteristics ....................................56Electrical Noise ..........................................................................57Crosstalk ....................................................................................57Attenuation ...............................................................................58Capacitance ...............................................................................58DC Resistance ............................................................................58Impedance .................................................................................58Continuity and Polarity ............................................................59Cable Length .............................................................................59

Limiting Noise and Crosstalk ...........................................................59Coaxial Cable ...................................................................................60

10Base5 ......................................................................................6110Base2 ......................................................................................62

The 5/4/3 Rule ....................................................................64Summary of Coaxial Wiring Rules .....................................64Other Coaxial Cabling Characteristics ..............................64

Twisted Pair Cable ............................................................................65UTP Cable ..................................................................................66STP Cable ...................................................................................68

10BaseT Star Topology .....................................................................69Other Twisted Pair Cabling Characteristics ..............................72

IBM Cable Types ..............................................................................72Type 1 ........................................................................................72

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Type 2 ........................................................................................72Type 3 ........................................................................................73Type 5 ........................................................................................73Type 6 ........................................................................................73Type 8 ........................................................................................73Type 9 ........................................................................................73


Lesson 6Fiber Optic Cable .................................................................77

Fiber Communication Systems ........................................................78Transmitter ................................................................................78Receiver .....................................................................................79

Fiber Optic Cable Construction .......................................................79Fiber Optic Dimensions ...................................................................80Types of Fiber Optic Cable ...............................................................81

Multimode Fiber ........................................................................81Step-Index Fiber .................................................................82Graded-Index Fiber ............................................................82

Single-Mode Fiber ......................................................................82Installing Fiber Optic Cable .............................................................83Review Questions .............................................................................84

Lesson 7Cable and Equipment Installation ........................................85

Structured Wiring Systems ...............................................................86Cable Convergence ...................................................................86Hub-Based Distributed Star Topology .......................................86Industry-Wide Standards ..........................................................87

The TIA/EIA-568 Standard ...............................................................88Structured Wiring Subsystems .........................................................88

Building Entrance ......................................................................89What Termination Means ..................................................89Punch-Down Blocks ...........................................................90Patch Panels .......................................................................91

Equipment Room ......................................................................92Vertical (Backbone) Cabling .....................................................92Wiring Closets ...........................................................................93Horizontal Wiring .....................................................................93Work Area ..................................................................................93Universal Wiring Subsystems ....................................................94Cabling Distances ......................................................................95Cabling Types ............................................................................95

General Cable Installation Guidelines .............................................96Equipment Installation Standards ...................................................97

NEC ...........................................................................................97NEBS ..........................................................................................98

Review Questions ...........................................................................100

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Contents

Lesson 8Cables and Connectors ......................................................102

Small UTP Cables ...........................................................................103RJ-45 Connectors ....................................................................103

Patch Cables and Crossover Cables ...............................................104Crossover Cables .....................................................................104Patch Cables ............................................................................105Connector Pinout Patterns .....................................................105

Building and Testing Small UTP Cables .........................................10725-Pair UTP Cables .........................................................................107

Identifying Wire Pairs in a 25-Pair Cable ................................107Quad Wire Cables ..........................................................................109

“Tip and Ring” Circuits ...........................................................109Circuit Polarity and Voltage ....................................................110RJ-11/RJ-14 Connectors ..........................................................110

Serial Cable Connections ...............................................................111RS-232 ......................................................................................111RS-422 ......................................................................................112V.35 .........................................................................................113

Review Questions ...........................................................................115Summary ...........................................................................117Quiz ..................................................................................119

Module 2A Layered System of Data Protocols ...............................127

Lesson 1Protocols and the OSI Model .............................................129

What is a Protocol? ........................................................................129A Simple Machine Protocol .....................................................130Protocol Headers .....................................................................131

Layers of Protocols and Services ....................................................131A Layered Communication System ........................................131

Encapsulation ...................................................................132Decapsulation ...................................................................132

Why Layers? ............................................................................132Layers of Computer Protocols .................................................133Layers of Services .....................................................................133Peer Processes ..........................................................................133

How Layers Work Together ...........................................................134Encapsulation and Protocol Headers ......................................134

Header Fields ....................................................................135Segmentation ...................................................................135

Decapsulation ..........................................................................135Reassembly ..............................................................................136

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The OSI Model ...............................................................................136The OSI Open Standard ..........................................................137The OSI Stack ..........................................................................137


Lesson 2The Physical Layer .............................................................142

Hardware Devices ...........................................................................142A Stream of Bits ..............................................................................143Minimal Error Detection ................................................................143Example: Manchester Encoding ....................................................144Review Questions ...........................................................................145

Lesson 3The Data Link Layer ...........................................................146

Frames Across a Link ......................................................................146Packets Within Frames ............................................................147Frame Addressing ....................................................................147

Data Link Layer Services ................................................................147On the Transmitting Node ......................................................147On the Receiving Node ...........................................................148

Error Detection and Correction: FCS .............................................149Data Link Layer Protocols ..............................................................150One Link, One Frame .....................................................................150Review Questions ...........................................................................152

Lesson 4The Network Layer ............................................................154

Packets Across Networks ................................................................154Network Layer Addresses vs. Data Link Layer Addresses ...............155

Data Link Addresses: Physical ..........................................155Network Addresses: Logical ..............................................156

Packet Routing ...............................................................................157Basic Data Transmission Methods .................................................158

Circuit Switching ....................................................................158Packet Switching .....................................................................159Connection-Oriented Networks ..............................................160Connectionless Networks .......................................................161

Network Layer Services ..................................................................162Network Layer Protocols ................................................................162Review Questions ...........................................................................163

Lesson 5The Transport Layer ...........................................................165

End-to-End Communication .........................................................166Transport Layer Services .................................................................167

Addressing ...............................................................................167Connection Management .......................................................167Flow Control and Buffering ....................................................168

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Contents

Multiplexing and Parallelization ............................................168Reliable and Sequenced Delivery ............................................169Service Quality Management ..................................................170

Transport Layer Protocols ..............................................................170Review Questions ...........................................................................171

Lesson 6The Session Layer ..............................................................173

Electronic Conversations ...............................................................173Establishing, Conducting, and Ending a Session ..........................174Dialogs ............................................................................................175

Token Passing ..........................................................................175Activity Management ..............................................................176Sync Points ..............................................................................176

Session Layer Protocols ..................................................................177Review Questions ...........................................................................178

Lesson 7The Presentation Layer .......................................................179

Computer Numbering ....................................................................179The Binary Numbering System ...............................................180The Hexadecimal Numbering System .....................................181

Presentation Layer Services ............................................................183Data Representation ................................................................183

Data Security ....................................................................184Data Compression ...................................................................185


Lesson 8The Application Layer ........................................................189

Common Application Layer Programs ..........................................190E-Mail ......................................................................................190USENET Newsgroups ...............................................................191File Transfer and Access ..........................................................191Virtual Terminals ....................................................................192Web Browsers and Servers .......................................................193


Module 3Data Networking Protocols .............................................201

Lesson 1 LAN Data Link Protocols ...................................................202

A Short History of the LAN ............................................................202When Mainframes Ruled the Earth ........................................202Enter the PC ............................................................................203

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New Data Link Protocols ................................................................203LLC Sublayer ...........................................................................203MAC Sublayer ..........................................................................204

The IEEE 802 Suite of LAN Protocols .............................................205Review Questions ...........................................................................207

Lesson 2Ethernet ............................................................................208

Ethernet Medium Access Control ..................................................208CSMA/CD ................................................................................210Ethernet Frame Addressing .....................................................211

Advantages and Disadvantages of Ethernet ...................................211Ethernet Configurations ................................................................212Fast Ethernet ..................................................................................213

Fast Ethernet Over Twisted Pair ..............................................213Fast Ethernet Over Fiber ..........................................................214Mixed Ethernet Networks .......................................................214

Gigabit Ethernet .............................................................................215Gigabit Ethernet Cabling and Distance Specifications ...........217

Fiber Cabling Specifications .............................................218Copper Cabling Specifications .........................................220


Lesson 3Token Ring and FDDI .........................................................222

Token Ring Medium Access Control .............................................222Types of Token-Passing Networks ..................................................223

Advantages of Token Ring ......................................................224Disadvantages of Token Ring ..................................................224

Token Ring Configurations ............................................................225FDDI ...............................................................................................227

Dual Channels .........................................................................228ETR and Multiple Messages .....................................................228Synchronous Traffic ................................................................229

Token Bus .......................................................................................229Review Questions ...........................................................................230

Lesson 4Point-to-Point WAN Services ..............................................233

Common Point-to-Point Services ..................................................234POTS Analog Connections .............................................................234

Modems ...................................................................................234Dial-Up Lines ...........................................................................236Leased Lines ............................................................................236PPP ...........................................................................................237

Zero Bit Insertion .............................................................237DSL .................................................................................................238

How DSL Works ......................................................................240DSL Physical Requirements .....................................................240

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Contents

Cable Modems ................................................................................241Cable Modem Configuration ..................................................242Shared Bandwidth ...................................................................242

Security .............................................................................243T-Carriers and E-Carriers ................................................................243

T1 Bandwidth ..........................................................................243DS Hierarchy ...........................................................................244FT1 ...........................................................................................245Customer Premises Equipment for T-Carriers ........................246Timing T-Carrier Circuits ........................................................247

The Carrier Interface ........................................................247The Local Network Interface ............................................248Preventing Clocking Problems .........................................249

ISDN ...............................................................................................249How ISDN Works ....................................................................249ISDN-BRI ..................................................................................249ISDN-PRI ..................................................................................251Channel Bonding ....................................................................252H Channels ..............................................................................252

SONET ............................................................................................253SONET Rings ...........................................................................254


Lesson 5Switched WAN Services .....................................................258

Circuits and Virtual Circuits ..........................................................259PVCs and SVCs ........................................................................260SVC Information Transfer .......................................................262

Types of Switched Services .............................................................263X.25 ................................................................................................263Frame Relay ....................................................................................264

Frame Relay Characteristics ....................................................267Frame Relay Implementation ..................................................267Local Management Interface ..................................................268

ATM ................................................................................................268Transfer Modes ........................................................................269ATM Characteristics ................................................................270

SMDS ..............................................................................................272SMDS Protocols .......................................................................272Advantages and Disadvantages ...............................................272

The Internet ...................................................................................272Internet Structure ....................................................................273Internet, Intranet, and Extranet .............................................273VPNs ........................................................................................274

Private vs. Public ............................................................................274Review Questions ...........................................................................275

Summary ...........................................................................277Quiz ..................................................................................278

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Module 4Data Networking Components .......................................285

Lesson 1Repeaters and Hubs ...........................................................287

Repeaters ........................................................................................287Hubs ...............................................................................................289Token Ring MAUs ..........................................................................290Token Ring Repeaters .....................................................................290Ethernet Collision Domains ..........................................................291

Hub-to-Hub Connectivity .......................................................292Stackable Hubs ...............................................................................294Chassis Hubs ..................................................................................295Review Questions ...........................................................................296

Lesson 2Bridges ..............................................................................299

Bridge Functionality .......................................................................299Traffic Isolation .......................................................................300

Types of Bridges .............................................................................302Bridge Algorithms ..........................................................................302

Transparent Bridging ..............................................................302Filtering and Forwarding ..................................................303Learning ...........................................................................304An Example of Learning, Filtering, and Forwarding .......304Active Loops .....................................................................306Spanning Tree Protocol ....................................................307

Source Route Bridging .............................................................309How Source Route Bridging Works ..................................310Internetworking with Source Route Bridges ....................311

Comparing Source Route Bridging to Transparent Bridging ..311Centralized vs. Distributed Function ...............................311Types of Networks Supported ..........................................312Overhead Traffic ...............................................................312Administration .................................................................312Complexity and Cost .......................................................312Flexibility ..........................................................................313

Source Route Transparent Bridging ........................................313Translation Bridging ...............................................................313


Lesson 3Switches ............................................................................319

Switch Functionality ......................................................................320Forwarding and Filtering .........................................................321Learning ..................................................................................322Switches as Bandwidth Multipliers .........................................322

Ethernet Switch Operation ............................................................323Speed vs. Accuracy ..................................................................323

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Contents

Port Buffering ..........................................................................324Port Switching to Eliminate Collisions ...................................324

Combining Switches With Hubs and Bridges ................................325Token Ring Switches ......................................................................327

Backbone and Workgroup Token Ring Switching ..................327Review Questions ...........................................................................332

Lesson 4Routers and VLANs ............................................................337

Introduction to Routers .................................................................338How Routers Work ..................................................................339Multiprotocol Routing ............................................................340

How Routers Move Packets Between Networks .............................340Routers Rebuild Frames ...........................................................341Internet Routers ......................................................................342Broadcast Domains .................................................................342

Routers for Broadcast Containment ................................344Router Advantages and Disadvantages ...................................344

Routing Tables ................................................................................345Static and Dynamic Routing ...................................................345Determining the Best Path ......................................................346

Related Devices ...............................................................................349Brouters ...................................................................................349Layer 3 Switches ......................................................................349

Comparing L3 Switches and Routers ...............................350Examples of Layer 3 Switching Techniques .....................350

Protocol Converters .......................................................................350VLANs .............................................................................................352

Switched VLANs ......................................................................353Routed VLANs .........................................................................354VLANs for Broadcast Containment ........................................355The Future of VLANs ...............................................................356


Lesson 5Network Servers ................................................................361

LAN Services ...................................................................................361File Servers ......................................................................................362

File Access Attributes ...............................................................363Synchronization ......................................................................364Semaphores (Flags) ..................................................................364Caching on File Servers ...........................................................364

Database Servers .............................................................................365Print Servers ...................................................................................365Web Servers ....................................................................................367

Web Caching ...........................................................................368Cache Servers ...................................................................369“Faster” or “Fresher” ........................................................369

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Application Servers .........................................................................369Application Platforms .............................................................370Types of Applications ..............................................................370

RAS (Communication Servers) .......................................................371RAS Platforms ..........................................................................371


Module 5TCP/IP Protocols and Services .........................................383

Lesson 1The TCP/IP Protocol Suite ..................................................385

TCP/IP Protocol Layers and the OSI Model ...................................385Network Interface Layer Protocols ..........................................386Internetwork Layer Protocols ..................................................386Transport Layer Protocols .......................................................387Application Layer Protocols ....................................................388

Communication Using TCP/IP ......................................................389Application Layer ....................................................................389Transport Layer .......................................................................389Network Layer .........................................................................390Network Interface Layer ..........................................................391Destination Station .................................................................391


Lesson 2IP .......................................................................................394

Overview of IP ................................................................................394Best-Effort Service ....................................................................395Multiplexing Protocols ............................................................396

IP Packet Encapsulation .................................................................396IP Version 6 ....................................................................................397

IPv6 Address Format ................................................................398IPv4 Compatibility ..................................................................398

ICMP ...............................................................................................399ICMP’s Purpose and Limits .....................................................399Encapsulation ..........................................................................399Message Types .........................................................................400

Destination Unreachable (3) ............................................401Source Quench (4) ............................................................401Redirect (5) .......................................................................402Echo Request (8) and Echo Reply (0) ...............................402Time Exceeded (11) ..........................................................402Parameter Problem (12) ....................................................402Timestamp Request (13) and Timestamp Reply (14) .......402

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Contents

Information Request (15) and Information Reply (16) ...403Address Mask Request (17) and Address Mask Reply (18) 403


Lesson 3Address Resolution: ARP and RARP .....................................407

ARP .................................................................................................407ARP's Operation .......................................................................407

ARP Request ......................................................................408ARP Response ...................................................................409ARP Features .....................................................................410

Proxy ARP ................................................................................411Frame Encapsulation ......................................................................411RARP ...............................................................................................412Review Questions ...........................................................................413

Lesson 4UDP and TCP .....................................................................415

Features Common to Both UDP and TCP .....................................415Demultiplexing Based on Port Number ..................................416Types of Port Numbers ............................................................418Well-Known Port Numbers .....................................................418Ports and Addressing ...............................................................420

UDP ................................................................................................420TCP .................................................................................................421

Basic Data Transfer ..................................................................421Reliable and Sequenced Packet Delivery .................................421Flow Control ...........................................................................422Multiplexing and Demultiplexing ..........................................422Connection Establishment .....................................................422

Sockets ..............................................................................423Review Questions ...........................................................................424

Lesson 5Internet Addressing ...........................................................427

IP Addresses ....................................................................................427Class A Address ........................................................................428Class B Address ........................................................................429Class C Address .......................................................................429Class D Address .......................................................................429Class E Address ........................................................................430

Dotted Decimal Notation ...............................................................430Addressing Rules ............................................................................431Sample Network Using Class A Address Format ............................431Getting an IP Network Address ......................................................432

Public Networks ......................................................................433Private Networks .....................................................................433


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Lesson 6Subnetting Fundamentals ..................................................437

The Value of Subnetting ................................................................437The IP Address Crisis ...............................................................438Why Multiple Network Segments? .........................................438

Interconnection of TCP/IP Networks .............................................438The Network Mask .........................................................................440Creating Subnets ............................................................................441IP Prefixes .......................................................................................442IP Broadcast Addresses ...................................................................442

Limited Broadcast ....................................................................443Directed Broadcast ..................................................................443

CIDR ...............................................................................................443Large Routing Tables ...............................................................444The Proposed Solution ............................................................445

How CIDR Works .............................................................445Reduction of Routing Table Entries ........................................447


Lesson 7IP Routing ..........................................................................450

Overview of Internet Architecture .................................................450Router Characteristics .............................................................452

Direct Routing ................................................................................452Indirect Routing .............................................................................453

Static Routing ..........................................................................455Default Routing .......................................................................455Dynamic Routing ....................................................................456

Building the Routing Table ............................................................456Sample Network Routing Table ..............................................458

How Routers Move Packets Between Networks .............................460Host A ......................................................................................461Packet on Network 128.1.0.0 ..................................................461Packet on Network 128.2.0.0 ..................................................461Packet on Network 128.3.0.0 ..................................................462Packet on Network 128.4.0.0 ..................................................463Host B ......................................................................................464

Review Question ............................................................................465

Lesson 8IP Address Management: BOOTP, DHCP, and NAT ............467

Bootstrap Protocol (BOOTP) ..........................................................467BOOTP Operation ...................................................................468

Client BOOTREQUEST Message .......................................468Server BOOTREPLY Message ............................................469

Client BOOTREPLY Message Receipt ......................................470The BOOTP Relay Agent .........................................................470

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Contents

TFTP ................................................................................................471DHCP ..............................................................................................471

DHCP Address Allocation Mechanisms ..................................472DHCP Operation .....................................................................473

DHCP Services ..................................................................473How DHCP Clients Obtain Configuration Information .474DHCP Client Lease Renewal ............................................476

DHCP Relay Agents .................................................................476IP Address Conflicts ................................................................477

NAT ................................................................................................478What is Address Reuse? ...........................................................478A NAT Overview ......................................................................478NAT Address Spaces .................................................................479IP Address Translation .............................................................479

Static Address Translation ................................................480Dynamic Address Translation ..........................................480

Enhanced Network Security ....................................................481Masquerading/NAPT ...............................................................482

How NAPT Works ............................................................482NAPT for More Security ...................................................485


Lesson 9IP Name Resolution: HOSTS, DNS, and WINS ....................490

HOSTS File ......................................................................................491DNS ................................................................................................492

Hierarchical Structure .............................................................492TLDs .................................................................................493Distributed Authority .......................................................494Second-Level Subdomains ................................................494Zones ................................................................................495

Domain Names ........................................................................495Types of Domain Names ..................................................496Domain Name Syntax ......................................................496

DNS Client/Server Operation ..................................................497Name Servers ....................................................................497Resolvers ...........................................................................497Querying the Name Database ..........................................498

NetBIOS Name Resolution .............................................................498Broadcasts ................................................................................499LMHOSTS file ..........................................................................499WINS .......................................................................................499

Name Resolution Challenges .........................................................500Incompatible Systems .............................................................500Static vs. Dynamic ...................................................................500


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Module 6The Public Telephone Network .......................................513

Lesson 1Local Exchange Components .............................................515

The Telephone System Hierarchy ..................................................516Class 5 Central Office: The Local Exchange ...........................517Class 4 Central Office ..............................................................519Tandem Central Offices ..........................................................520Class 1 Office ...........................................................................522

Class 5 Central Office Components ..............................................523Switching and Routing ............................................................523Semipermanent Circuit Connections .....................................524IXC POP ..................................................................................525Billing ......................................................................................525Customer Premises ..................................................................525

Local Exchange Calling Options ....................................................526LEC Does It All ........................................................................526CLEC Serves as Reseller ...........................................................526CLECs Switch and ILECs Wire ................................................526CLEC Does It All ......................................................................527


Lesson 2Central Office Switching ....................................................530

The Talking Path ............................................................................530Digital Switches ..............................................................................532How a Call is Made ........................................................................532

Call Setup ................................................................................533Call Connection ......................................................................533Call Completion ......................................................................536Ending the Call .......................................................................536

Telephone Numbering System .......................................................536NANP .......................................................................................536International Numbering Plan ................................................537Global Numbering Plan ..........................................................538

Special Area Codes .........................................................................538Special NXX Codes ..................................................................539

Special Information: 555 ..................................................539Hearing-Impaired Services: 800-855 ................................539

Service Codes ...........................................................................539Follow-Me: 500 ........................................................................539International: 700 ...................................................................539Toll-Free: 800, 888, 877, 866 ...................................................540Premium: 900 ..........................................................................540


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Contents

Lesson 3Trunks, Lines, and Loops ....................................................542

Telecommunications Terms ...........................................................543Loops ..............................................................................................544Lines ...............................................................................................544Trunks .............................................................................................544

Trunk Direction .......................................................................545Trunk Capacity ........................................................................545Analog or Digital Transmission ..............................................545

Converting Analog Voice to Digital .................................545Multiplexing .....................................................................547Digital Channels ..............................................................547

Special Access Trunks .....................................................................548Tie Lines ..................................................................................548Private Lines ............................................................................549FX ............................................................................................549

Foreign Exchange Interfaces ............................................550Ring Down ..............................................................................551Trunk Pricing ...........................................................................551


Lesson 4Analog Voice Impairments .................................................555

Analog Transmission Impairments ................................................555Noise ........................................................................................556Echo .........................................................................................556Crosstalk ..................................................................................557Delay ........................................................................................558Loss (Attenuation) ...................................................................558

Analog Signal Filtering: A Special Case ..........................................558Review Questions ...........................................................................561

Lesson 5Small Office Telephone Equipment ....................................562

Key Systems ....................................................................................562Key System Components ........................................................562Cordless Key Systems ..............................................................564Limitations of Key Systems .....................................................565Hybrid Systems ........................................................................565

Central Office Exchange (Centrex) ................................................565How Centrex Works ................................................................566Centrex Benefits ......................................................................567Technical Requirements for Centrex ......................................567

Distance From CO Switch ................................................567Allocation of Call Paths ...................................................568CPE ...................................................................................568

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Centrex Features ......................................................................568Centrex vs. PBX .......................................................................569Combining Centrex with Other Switching Systems ..............569


Lesson 6Private Branch Exchange ....................................................573

PBX Components ...........................................................................573Trunks ......................................................................................574Extension Lines .......................................................................575Equipment Cabinet .................................................................575Telephones and Attendant Console .......................................576Administrative Terminal .........................................................577

Making a Call on a PBX .................................................................577Call Routing ...................................................................................577Supplementary PBX Features .........................................................578

DID ..........................................................................................579DISA .........................................................................................580UDP .........................................................................................580

Station Set Features ........................................................................581Attendant Console Services ...........................................................582Call Accounting .............................................................................583

Authorization Codes ...............................................................584Account Codes ........................................................................584

Administration and Management Reports ....................................585Call Detail Reports ..................................................................585Test Reports .............................................................................585Busy-Hour Studies ...................................................................585

PBX Enhancements ........................................................................586Voice Response ........................................................................586Voice Recognition ...................................................................586Call Following .........................................................................586ACD .........................................................................................587Other Auxiliary Equipment ....................................................587Paging Equipment ...................................................................587CMS .........................................................................................588


Lesson 7Voice Mail Systems ............................................................592

Voice Mail Features ........................................................................592Voice Mail/PBX Integration ....................................................593Design Factors .........................................................................594Unified Messaging ...................................................................595Broadcasting ............................................................................595Voice Mail Security .................................................................595

Automated Attendants ...................................................................597Review Questions ...........................................................................598

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Contents

Lesson 8Signaling Basics .................................................................600

Supervisory Signals .........................................................................601Loop Start ................................................................................602Ground Start ............................................................................603E&M .........................................................................................605Emulated Tie Trunks ...............................................................605Wink Start ...............................................................................606Digital Signaling ......................................................................606

T1 Framing and A,B,C, and D bits ...................................607E1 Framing and Signaling ................................................609

Address Signals ...............................................................................610Dial Pulse Signaling .................................................................610Dual Tone Multifrequency (Touch Tone) Signaling ...............611

Alerting Signals ..............................................................................612Control Signals ...............................................................................612In-Band vs. Out-of-Band Signaling ................................................612Review Questions ...........................................................................613

Lesson 9SS7 ....................................................................................616

The Need for SS7 ............................................................................616SS7 Integrated Services ...................................................................617SS7 Architecture .............................................................................618

SSP ...........................................................................................618STP ...........................................................................................618SCP ..........................................................................................619SS7 Network Links ...................................................................619

SS7 Call Signaling Steps .................................................................620LNP ..........................................................................................621SS7 Protocol Stack ...................................................................621

MTP ..................................................................................622ISUP and TUP ...................................................................622SCCP .................................................................................623TCAP .................................................................................623


Lesson 10ISDN .................................................................................626

ISDN Protocols ...............................................................................626DSS1 ................................................................................................627

DSS1 Protocols .........................................................................628Physical Layer: I.430, I.431 ..............................................628Data Link Layer Call Setup: LAPD ...................................628Network Layer Call Control, I.451/Q.931 .......................629Network Layer Packet-Switching, X.25 ............................629

I.451/Q.931 Signaling .............................................................629

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QSIG ...............................................................................................630DCE and DTE .................................................................................632

DTE-to-DCE Protocols .............................................................632Layer Upon Layer ....................................................................633

ISDN CPE ........................................................................................634Supported Switch Types ..........................................................636


Module 7Convergence ....................................................................651

Lesson 1Packet Telephony ..............................................................653

The Present: Separate Networks .....................................................654How Packet Telephony Works .......................................................655

Making the Shift ......................................................................656Packet Telephony Standards ..........................................................658Internet Telephony Categories ......................................................659

Computer-to-Computer ..........................................................659Computer-to-Telephone .........................................................660Telephone-to-Telephone .........................................................661Web-to-Call Center Systems ...................................................662

Telephony Gateway .......................................................................662Dedicated Servers with Voice Cards ........................................663Router or Access Concentrator with Voice Cards ...................664

Packet Telephony Products ............................................................664Toll Bypass Products ................................................................665LAN-Based PBX Systems ..........................................................665The UnPBX ..............................................................................665


Lesson 2General QoS Concepts ......................................................668

Network Requirements for Convergence .......................................668Converged Network Architecture ..................................................669

A Hybrid Approach to Convergence .......................................669Parallel WAN Paths for QoS ....................................................670Application-Level QoS .............................................................671

Voice Quality ..................................................................................671The QoS Parameters .......................................................................672

Bandwidth ...............................................................................673Throughput .............................................................................673Delay ........................................................................................674

Encoding, Decoding, and Compression ..........................675Packetization ....................................................................675

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Contents

Jitter .........................................................................................676Jitter Buffers ......................................................................676Measuring Jitter ................................................................677

Wander ....................................................................................678Packet Loss ..............................................................................678Availability ..............................................................................679Security ....................................................................................680


Lesson 3Overview of Telecommunications Standards ......................684

ITU-T Protocols ..............................................................................684Commercial Telecommunica-tions Standards ........................685Codecs .....................................................................................685Multimedia Call Control and Signaling .................................686

H.32x–Multimedia over Data Networks ..........................687Call Setup, Signaling, and Control Protocols ..................687Supplementary Packet Telephony Services ......................689

ISDN Protocols ........................................................................689ISDN Switching and Signaling Protocols ................................690Terminal Protocols ..................................................................690Data Communications over the Voice Network .....................691Packet Data Network Protocols ...............................................691

IEEE .................................................................................................692ANSI ................................................................................................692Telcordia .........................................................................................693EIA and TIA ....................................................................................694IETF .................................................................................................695

RFCs .........................................................................................695Internet Standards ...................................................................695BCP ..........................................................................................695


Lesson 4Admission Control and Traffic Shaping ..............................699

Admission Control .........................................................................699Traffic Shaping ...............................................................................701

Traffic Smoothing ...................................................................702Traffic Burst Shaping ...............................................................703

Network Admission Policies ...........................................................703Admission Control and Traffic Shaping Applications ...................705Review Questions ...........................................................................707

Lesson 5Traffic Prioritization ............................................................709

802.1Q VLAN Standard ..................................................................709The VLAN Tag .........................................................................709802.1Q as an Architecture .......................................................711

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802.1Q Protocols .....................................................................711802.1p Traffic Prioritization Standard ...........................................712

Priority Tags and Traffic Classes .............................................712How 802.1p Prioritizes Traffic .................................................713Mapping 802.1p Traffic Prioritization to IP

and ATM Networks ..............................................................714Review Questions ...........................................................................715

Lesson 6H.323 Standard for Packet Multimedia ..............................718

Overview of the H.323 Standard ....................................................718Version 1: Videophone ...........................................................719Version 2: Packet-Based Multimedia .......................................719Version 3: Under Development ..............................................719

Other Standards of the H.323 Family ............................................719Fundamental H.323 Network Components ..................................720

Terminals .................................................................................720MCUs .......................................................................................720Gateways .................................................................................721Gatekeepers .............................................................................722

MGCP .............................................................................................723MGCP Network Components .................................................723

MG ....................................................................................724MGC .................................................................................725

The H.323 Protocols and Their Effect on Voice Stream QoS .........725H.323 Protocols .......................................................................725Audio Codecs ..........................................................................726

Silence Suppression ..........................................................727G.711 Companding Algorithms ......................................727MOS ..................................................................................729Audio Codec Delays .........................................................729DSPs ..................................................................................730DSP Delays ........................................................................730

RTP ..........................................................................................730Time Stamping .................................................................731Sequencing .......................................................................731

RTCP ........................................................................................732RAS: H.225 ...............................................................................732Call Signaling: H.225 ..............................................................732Control Signaling: H.245 ........................................................732H.323 Protocol Limitations .....................................................733Document Conferencing: T.120 Series ...................................733

Integration with the Digital PSTN .................................................733ISDN/VoIP Integration ............................................................733Adding SS7 to VoIP .................................................................734

Network Infrastructure Requirements ...........................................736Review Questions ...........................................................................737

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Contents

Lesson 7H.323 Call Processing ........................................................740

H.323 Call Progression Phases .......................................................740Gatekeeper Discovery and Registration: H.225 RAS ...............741Call Setup and Signaling: H.225 .............................................742Control Signaling: H.245 ........................................................745Call Termination: H.245/H.225 ..............................................747

H.323v2 fastStart ............................................................................748SIP ...................................................................................................750SS7 to ITSP Call Progression ...........................................................750Review Questions ...........................................................................753

Lesson 8Session Initiation Protocol ..................................................756

SIP ...................................................................................................756SIP Messages ...................................................................................758

Request Messages ....................................................................758SIP Addresses ....................................................................759Request Message Format ..................................................759

Response Messages ..................................................................760Response Message Format ................................................761

SIP Servers .......................................................................................761Proxy .......................................................................................761Redirect ....................................................................................762Registrar ...................................................................................762

SIP Clients ......................................................................................762SDP .................................................................................................762Creating a SIP Session ....................................................................764Activities ........................................................................................766

Lesson 9Approaches to IP Network QoS .........................................768

IP Header Features ..........................................................................768ToS Field ..................................................................................768IP Precedence ...........................................................................769

DiffServ ...........................................................................................769DSCP Code Points ...................................................................769PHB ..........................................................................................770

Standard PHBs ..................................................................770Custom PHBs ....................................................................771

DiffServ Domains ....................................................................771IntServ ............................................................................................771

RSVP ........................................................................................772CBQ ................................................................................................772COPS ...............................................................................................773MPLS ...............................................................................................775Policy Routing ................................................................................777PQ ...................................................................................................777

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RED .................................................................................................777Traffic Shaping ...............................................................................777WFQ ...............................................................................................778WRED .............................................................................................778Review Questions ...........................................................................779

Summary ...........................................................................781Quiz ..................................................................................783

Module 8Troubleshooting ..............................................................791

Lesson 1Common Network Testing Tools .......................................793

Winipcfg, IPconfig, and IFconfig ...................................................794Winipcfg Operation ................................................................794IPconfig Operation ..................................................................796IFconfig Operation ..................................................................798

Ping ................................................................................................799Command Line Switches ........................................................800

Tracert or Traceroute ......................................................................802Command Line Switches ........................................................804

Netstat ............................................................................................804Command Line Switches ........................................................805Repeating a Netstat Command ...............................................806

ARP .................................................................................................806Command Line Switches ........................................................807Changing the ARP Cache ........................................................808

Common IP Configuration Errors .................................................809Duplicate IP Addresses ............................................................809Default Gateway Addressing Errors .........................................810Address/Subnet Mismatch ......................................................811

Protocol Analyzers (Sniffers) ..........................................................812Components of a LAN Protocol Analyzer ...............................812Protocol Analyzer Traces .........................................................813

BERT ...............................................................................................814Testing Physical Media ...................................................................815

Copper Cables .........................................................................815Tone Generator and Probe ...............................................815Media Tester/Certifier ......................................................816Hub, Switch, and Router Indicators .................................818Lineman’s Test Set (Butt Set) ............................................819

Optical Fiber ............................................................................820Wireless LANs ..........................................................................820

Review Questions ..........................................................................821

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Contents

Lesson 2A Step-by-Step Method .....................................................824

Troubleshooting Steps ....................................................................8241. Establish the Symptoms ......................................................8252. Identify the Affected Area ...................................................8263. Establish What Has Changed ..............................................8264. Select the Most Probable Cause ..........................................8275. Implement a Solution .........................................................8276. Test the Result .....................................................................8277. Recognize the Potential Effects of the Solution ..................8288. Document the Solution ......................................................828


Lesson 3Troubleshooting a Wiring Problem ....................................831

The Problem ...................................................................................831Establish the Symptoms ..........................................................831Identify the Affected Area .......................................................832Establish What Has Changed ..................................................832Select the Most Probable Cause ..............................................832Implement a Solution .............................................................832Test the Result .........................................................................833Recognize the Potential Effects of the Solution ......................833Document the Solution ..........................................................833


Lesson 4Converged Network Failure Points .....................................836

Potential Network Failure Points ...................................................836Converged Network To PSTN Interface ..................................837

Admission Errors ..............................................................837Echo and Noise .................................................................838

The LAN ..................................................................................840Protocol Overhead ...........................................................840Percent of Frame Overhead ..............................................841Actual Codec Bandwidth Required ..................................841The Effect of Protocol Overhead on VoIP Networks .......843IP Multicast Traffic ...........................................................843Network Performance ......................................................845

The WAN .................................................................................847WAN Routing and Reliability ..........................................847Backup Paths ....................................................................847Load Sharing ....................................................................850


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Lesson 5A Converged Network Troubleshooting Example ...............855

A Network Problem Example .........................................................855Initial Testing ..........................................................................856Digging Deeper ........................................................................857The Fix .....................................................................................859


Course Quiz ......................................................................871

Index ................................................................................895

Glossary ............................................................................919

Notes ................................................................................955

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