LAN Times Guide to Building High-Speed Networks

Tere Parnell

Osborne McGraw-Hill Berkeley New York St. Louis San Francisco

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Contents Acknowledgments xxiii Introduction xxv

If 111 1 Do You Really Need a High-Speed Network? 3 Read This First 4

Ask Yourself Why 4 It May Be Bandwidth 5 And Then Again, It May Not Be Bandwidth 6

Server-Related Performance Problems 6 Processor Speed 6 Disk Subsystem 6 Random Access Memory 7

Network-Related Performance Problems 7 Network Interface Card Selection 7

Xi

Chattering Cards 8 Poor Network Interface Card Driver Support 8

Workstation-Related Performance Problems 8 How to Determine that High-Speed Networking Will Help 9

Step One: Evaluate Your Server Usage 9 Step Two: Evaluate Your Server Configuration 10 Step Three: Evaluate Workstations 11 Step Four: Evaluate Current Application Requirements 12 Step Five: Evaluate Future Application Requirements 15 Step Six: Evaluate Network Usage 15 Step Seven: Read On 17

111 II 2 The Backbone Is Connected to the 19 How It All Began 20

Types of Backbones 21 Why Build a Backbone? 22 How Do You Build a Backbone? 27 The Effects of Excessive Internetwork Traffic 29 Causes and Cures for a Clogged Backbone 29 The Final Analysis 31 WhatYouGain 31 Selecting a High-Speed Backbone Protocol 32

11111 3 Down on the Farm 35 Do Servers Grow on Farms? 36

Enterprise-Wide Access to Information 37 Distribute Processing Load Across Specialized Platforms 39

Implementations of Distributed Computing Systems 40 Distributed Application Processing 40 Distributed Databases 41 Data Warehousing 41

Building Blocks of Distributed Computing Systems 42 Relational Databases 42 Structured Query Language 42 Middleware 43

Data Propagation 46 Network Requirements of a Server Farm 47 Indications of Bandwidth Drought on the Farm 48 Other Causes and Cures for Slow Performance on the Server Farm 49

Location of Data and Applications 49 Inadequate Hardware 49 Buying the Farm 49

11111 4 Closer to Home 51 When Is a Workgroup Powerful? 52 Electronic Mail and Messaging 52

An Electronic Mail System 52 Electronic Messaging Systems 53 Electronic Messaging Systems, Standards, and Tools 54

The Internet 57 Client-Server Applications 57

Client-Server Architecture 57 How to Build a Client-Server Application to Minimize Traffic 58 Effects of Client-Server Computing on Network Traffic 59

Multimedia 60 Workflow Software 60

Groupware 61 Groupware in Action 62 Groupware Tools 63

Group Therapy 63 Location of Applications 63 Inadequate Hardware 64 "Chatty" Communication Protocols 64 Small Packet Size 65 Group Encounters 66

Group Things 66

11111 5 The Wide Area 67 Why Are We Talking About Wide Area Protocols in This Book? 68

The Wide Area Defined 68 Dedicated versus Switched Lines 69 Public Networks 72 Private Networks 73 A Word About Routers and Routing 74 Analog Lines 75 Digital Lines 75

Carrier Services 75 Symptoms of a Bandwidth Shortage Over the Wide Area . . . 78

Inadequate Hardware 78 Location of Applications 78 Traffic Patterns 79 Packet Size 79 "Chatty" Communication Protocols 79

Tests to Confirm Insufficient WAN Bandwidth 80 Requirements for Wide Area Protocols 80

Performance 81 Manageability 81 Packet Size and Overhead 81 Cost 81

Hill 6 The Cost of Converting to High Speed 83 To Speed or Not to Speed 84 Hardware Worksheet 85

Servers 85 Hubs 85 Routers 86 Switches 86 Workstations 86 And a Smooth Road 86

Service Cost Worksheet 86 Staffing and Staff Development Worksheet 87 Time Estimate Worksheet 87 Applications Worksheet 87

Live Fast, Die Young 88 If You Still Find It's Worth It 88

Ulli 7 Fiber Distributed Data Interface (FDDI) 101 What Makes It the Same—and What Makes It Different . . . 102

Framing the Data 103 Determining the Path 104 Cabling Considerations 106 Cost of Ownership 108 Scalability 109 Setup and Configuration 110 Manageability Il l Performance 112 Evolving to Survive 113

Summary 113

Hill 8 lOOVG-AnyLAN 115 So Close, But So Far from 10Base-T 116

Getting Framed 117 The Architecture 117 Cable Design Considerations 119 Preparing for lOOVG-AnyLAN 122 Scalability 123 Manageability 125 Performance 125 Continuous Improvement 125

Summary 125

l l l i l 9 100Base-T 127 A Smorgasbord of Specs 128 Understanding the Differences Between 100Base-T and 10Base-T 132

Interoperability and Obstacles 133 Scalability Considerations 135 Manageability Issues 136 Setup and Configuration Considerations 136

Summary 137

HUI 10 Thomas-Conrad Networking System (TCNS) 139 The Successor of ARCNET 140

The Architecture 141 Cost of Ownership 142 Scalability 143 Setup & Configuration 143 Manageability 144 Performance 145 Special Applications of TCNS 145 It's Getting Better, But 145

Summary - 145

1I11I 11 Fibre Channel 147 Going Through Channels 148 The Standard and Its Supporting Groups 149 How Do They Do That? 151

Fibre Channel Layer 0 (FC-0): The Physical Interface . . . 152 Fibre Channel Layer 1 (FC-1): The Transmission Protocol 153 Fibre Channel Layer 2 (FC-2): Signaling Protocol 153 Fibre Channel Layer 3 (FC-3): Common Services 157 Fibre Channel Layer 4 (FC-4): Upper Layer Protocol Mapping 157

Cabling Considerations 157 Brave New Topology 158

Installation and Configuration 158 Interoperability 159 Scalability 159 Manageability and Fault Tolerance 160 Performance 161

Advantages: Fibre Channel vs. ATM 161 Disadvantages 162

11111 12 IsoEthernet 163 The Second Coming of Ethernet 164 The IEEE 802.9a (IsoEthernet) Standard 164 In the Beginning, There Was Ethernet 165 Enter IsoEthernet 166

Two Networks in One 166

Time Division Multiplexing 169 Clockers 170

The Benefits of IsoEthernet 170 IsoEthemet and Wide Area Support 170 IsoEthernet and Videoconferencing 171 Manageability 171 Scalability 171 Cost 171 Security and Fault Tolerance 172 Performance 172 Ease of Installation/Maintenance 172

Disadvantages of IsoEthernet 174 Future Trends 174

The Isochronous Network Communication Alliance 174

How to Spued Up: Wide Area Solutions

i l l !-13 Integrated Services Digital Network 179 The Primordial Mire 180 Anatomy of the ISDN Species 181

Channel Types 181 It's All in the Packaging 182

Basic Rate Interface ISDN 182 Primary Rate Interface ISDN 183

ISDN's Function in the Wide Area Food Chain 183 Great Moments in Evolution: SPID-ing in the Ocean 185

The Goal of Evolution: What These Services Can Provide . . 186 Bearer Services 186 Supplementary Services 188 Teleservices 189

Making ISDN Happen 189 The Local Exchange Carrier's Part 189 The Home Front 191 Configuration and Installation 193 Cabling Considerations 197 Performance 197

Management and Fault Tolerance 198 Scalability 198 Availability and Pricing 199

The Future: Broadband ISDN 199 Advantages 200 Disadvantages 200

111II 14 Switched Multimegabit Data Service 201 What Is ...? 202

Cellbased? 204 Switched? 204 Connectionless? 204 The Architecture 205 Standards Compliance 205

Where...? 206 How ...? 207

Access Method 207 Why ...? 207

Installation and Configuration 208 Manageability 208 Scalability 210 Interoperability 210 Performance 210 Cost 210

Support Group 211 Disadvantages 211

Limited Multimedia Support 211 Limited Usage 211 Limited Vendor Support 212

The Future 212

l u l l 15 Frame Relay 213 SonoflSDN 214 What It Is 214 How It Works 214

Frame Relay vs. Packet Switching 215 Frame Format 217 Frame Relay Network Devices 218

Frame Relay Connections 219 Relief for a Stuffy Network 219 Getting What You Pay for 220 Management and How Little There Is of It 221 Statistical Multiplexing and Bandwidth on Demand . . . 221 Installation and Configuration 223 Availability and Pricing 224 Management and Fault Tolerance 224 Interoperability 225 Performance 226 Scalability 226

Can Your Vendor Do This? 226 The Experience Question 227 The Interoperability Question 227 The Performance Question 227 The Management Questions 228

The Good News 228 The Bad News 230

Voice and Frame Relay 230 Frame Relay Forum 230

11111 16 Asynchronous Transfer Mode 233 How It Started 235 Who Started It 235 ATM: The Short Answer 236 If ATM Is the Answer, What Were the Questions? 236

What Is a Cell? 236 What is Switched? 237 What Is Connection-Oriented? 239 What Is Full-Duplex? 239 What Is Point-to-Point? 239 What Is Dedicated Bandwidth? 240

How It All Works Together 240 Route Determination 241 Data Forwarding 241 Cabling Considerations 242 Setup and Configuration 243 Scalability 243 Manageability 245

Performance 248 Fault Tolerance 249 Security 249 Cost of Ownership 249

The ATM and the OSI Model 249 TheATMLayer 250 The ATM Adaptation Layer (AAL) 250

ATM Migration Issues 251 Incomplete Interface Specifications 252 LAN Emulation 252 Routing Issues 257 Incomplete Product Lines 261 Training Holes 261

Expect to Phase it In 261 Desktop Migration Issues 263 WAN Integration Issues 265

ATM and Voice 268 The Promised LAN 268

11111 17 Alternatives to High-Speed Networking 273 Network Segmentation 274

A Segment Defined 274 Creating Internetworks 275 The Bridging Primer 277 Bridge Performance Issues 285 The Router Primer 285 The Router Shopping Guide 288 Planning Segmented Networks 289 Microsegmentation 289

Switching 290 Making the Switch 290 Which Switch? 293 Analysis Is Key 299 10/100 Switching 301

Full-Duplex Protocols 303 Virtual LANs 303

A Time for Everything 305

l l l l l 18 Speed Kills: Avoiding a Crash 309 First: Try Before You Buy 310 Second: Identify the Next Bottleneck 310 Third: Make a Schedule 311

Class Time 311 Fourth: Get Your Budget Approved 311

It's a Wonderful Life 314 Doomsayer 315 Considering the Alternative 315 The Price Is Right 315 Benefit Analysis 316 Showtime 316 You Can't Always Get What You Want 316

Fifth: Set Expectations 317 Surviving Speed 318

Appendixes

l l l l l A Open Systems 321 Specifying Open Systems 322

Move to Interoperability . . . " 323 Open Systems Interconnection (OSI) Model 324

Ulli B The Standards Organizations 331 American National Standards Institute (ANSI) 332 International Consultative Committee for Telegraph and Telephone (CCITT) 332 Institute of Electrical and Electronic Engineers (IEEE) . . . . 333 International Standards Organization (ISO) 334

11111 C The Supporting Organizations 335 100Base-T: The Fast Ethernet Alliance 336 The lOOVG-AnyLAN Forum 336 Asynchronous Transfer Mode: The ATM Forum 337 Fibre Channel: The Fibre Channel Association 337 Frame Relay: The Frame Relay Forum 338

isoEthemet: The isochronous network communication Alliance (incAlliance) 338 Integrated Services Digital Network (ISDN) 339 Switched Multimegabit Data Service (SMDS) 339

I ill! D Bibliography 341

lllll Index 343