Mission-Critical Network Planning For a listing of recent titles in the Artech House Telecommunications Library, turn to the back of this book Mission-Critical Network Planning Matthew Liotine Artech House, Inc Boston • London www.artechhouse.com Library of Congress Cataloging-in-Publication Data Library of Congress CIP information is available on request British Library Cataloguing in Publication Data Liotine, Matthew Mission-critical network planning —(Artech House telecommunications library) Computer networks—Design and construction Business enterprises—Computer networks I Title 004.6 ISBN 1-58053-516-X Cover design by Igor Valdman © 2003 ARTECH HOUSE, INC 685 Canton Street Norwood, MA 02062 All rights reserved Printed and bound in the United States of America No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized Artech House cannot attest to the accuracy of this information Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark International Standard Book Number: 1-58053-516-X A Library of Congress Catalog Card number is available for this book 10 To Camille and Joseph—this is for them to remember me by Contents Foreword Preface Acknowledgments CHAPTER Introduction 1.1 1.2 1.3 1.4 1.5 1.6 1.7 What Is Mission Critical? Purpose of the Book Network Continuity Versus Disaster Recovery The Case for Mission-Critical Planning Trends Affecting Continuity Planning Mission Goals and Objectives Organization of the Book References CHAPTER Principles of Continuity 2.1 Fault Mechanics 2.1.1 Disruptions 2.1.2 Containment 2.1.3 Errors 2.1.4 Failover 2.1.5 Recovery 2.1.6 Contingency 2.1.7 Resumption 2.2 Principles of Redundancy 2.2.1 Single Points of Failure 2.2.2 Types of Redundancy 2.3 Principles of Tolerance 2.3.1 Fault Tolerance 2.3.2 Fault Resilience 2.3.3 High Availability 2.4 Principles of Design 2.4.1 Partitioning 2.4.2 Balance xv xvii xviii 1 2 9 10 11 11 12 13 13 14 14 14 16 20 21 22 22 22 23 23 vii viii Contents 2.4.3 Network Scale 2.4.4 Complexity 2.5 Summary and Conclusions References 25 27 28 29 CHAPTER Continuity Metrics 31 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 Recovery Metrics 3.1.1 Recovery Time Objective 3.1.2 Recovery Point Objective 3.1.3 RTO Versus RPO Reliability Metrics 3.2.1 Mean Time to Failure 3.2.2 Failure Rate 3.2.3 Mean Time to Recovery 3.2.4 Mean Time Between Failure 3.2.5 Reliability Availability Metrics Exposure Metrics Risk/Loss Metrics Cost Metrics Capacity Metrics 3.7.1 Utilization 3.7.2 Bandwidth 3.7.3 Overhead Performance Metrics 3.8.1 Latency 3.8.2 Response Time 3.8.3 Loss 3.8.4 Error 3.8.5 Throughput Summary and Conclusions References CHAPTER Network Topology and Protocol Considerations for Continuity 4.1 Network Topology 4.1.1 Fundamental Topologies 4.1.2 Mesh Topologies 4.1.3 Ring Topologies 4.1.4 Tiered Topologies 4.1.5 Edge Topologies 4.1.6 Peer-to-Peer Topologies 4.2 Network Protocol Considerations 4.3 Summary and Conclusions References 32 32 35 36 36 37 37 38 38 40 42 47 47 48 52 52 53 54 55 55 57 57 57 58 59 60 63 63 64 65 67 68 69 69 70 71 72 Contents CHAPTER Networking Technologies for Continuity 5.1 ix 73 Local Area Networks 5.1.1 Ethernet 5.1.2 Switching Versus Segmenting 5.1.3 Backbone Switching 5.1.4 Link Redundancy 5.1.5 Multilayer LAN Switching 5.1.6 Virtual LANs 5.1.7 Transceivers 5.1.8 Media Translators 5.1.9 Network Adapter Techniques 5.1.10 Dynamic Hierarchical Configuration Protocol 5.2 Wide Area Networks 5.2.1 WAN Technologies 5.2.2 Routing Methods 5.2.3 Multilayer WAN Switching 5.2.4 Design Strategies 5.2.5 VPNs 5.3 Metropolitan Area Networks 5.3.1 Metro Ethernet 5.3.2 RPR 5.4 Summary and Conclusions References 73 74 76 77 78 78 78 79 80 80 82 83 83 90 96 101 102 103 104 106 108 109 CHAPTER Processing, Load Control, and Internetworking for Continuity 113 6.1 Clusters 6.1.1 Cluster Types 6.1.2 Cluster Resources 6.1.3 Cluster Applications 6.1.4 Cluster Design Criteria 6.1.5 Cluster Failover 6.1.6 Cluster Management 6.1.7 Cluster Data 6.1.8 Wide Area Clusters 6.2 Load Balancing 6.2.1 Redirection Methods 6.2.2 DNS Redirection 6.2.3 SSL Considerations 6.2.4 Cookie Redirection 6.2.5 Load Balancer Technologies 6.2.6 Load Balancer Caveats 6.3 Internetworking 6.3.1 Web Site Performance Management 6.3.2 Web Site Design 6.3.3 Web Services 113 114 117 118 118 119 120 121 122 123 125 128 128 129 129 131 132 132 135 137 400 Backups (continued) continuous, 246 creation steps, 243 daily, 243 differential, 247 full, 244–45 incremental, 245–46 performing, 244 plans, 243 serverless, 257 summary, 283 See also Storage Balance, 23–25 centralization, 24 decentralization, 24–25 defined, 23 See also Design(s) Bandwidth, 53 Batteries, 311 Bit error rate (BER), 71 Border gateway protocol (BGP), 91, 93–94 defined, 93 example, 94 precautions, 93–94 See also WAN routing Broadcast, 172 Burst capacity, 52 Buses, 187–88 CompactPCI, 188 CPSB, 188 Infiniband, 188 ISA, 187 PCI, 187–88 VME, 188 C Cable plant, 291–301 cabling practices, 292–96 campus, 295–96 carrier entry, 292–93 copper, 296–99 features, 291 fiber-optic, 299–301 mission-critical, 294 multiple tenant units (MTUs), 293–95 service entrance, 292 summary, 319–20 See also Facilities Caching, 143–49 benefits and drawbacks, 145–46 CDNs, 146–49 defective, 146 Index defined, 143 forward proxy, 144–45 reverse proxy, 145 solution types, 144–45 summary, 150 Campus, 295–96 mission-critical network design, 296 simple network design, 295 See also Cable plant Capacity effectiveness, 23 metrics, 52–54 stranded, 68 Capacity planning, 338–41, 355 MPLS, 340–41 optimization and, 338 performing, 338 RSVP, 341 system utilization and, 339 tool characteristics, 340 tools, 339 See also Traffic Carrier services, 159–62 call reroute capabilities, 160 carrier commonality, 159–60 grade of service (GOS), 161 IXC redundancy, 162 line quality, 162 path diversity, 160–61 problem resolution/escalation, 161–62 survivable switch architecture, 161 telephony infrastructure, 162 wire center diversity, 160 See also Voice network access Carrier SLAs, 352–53 Carrier/supplier management, 333–34 Cellular service, 167–68 Centralization, 24 Change management, 353–54 Checkpoint management, 194 Clusters, 113–23 administrative, 117 application portability, 121 applications, 118 data, 121–22 defined, 113 design criteria, 118–19 dynamic, 114 failover, 119–20 fault-tolerant systems, 116 high-availability, 117 high performance, 117 Index load balancing, 121, 124–25 management, 120–21 monitoring, 121 multiprocessor, 116 node addition, 121 node removal, 121 OS migration, 121 Parallel Sysplex, 123 resources, 117–18 server, 116 services, 116–17 software requirement, 114 static, 114 summary, 149 super, 114 technologies, 115 types of, 114–17 uses, 114 wide area, 122–23 Cold failover, 12, 13 Cold sites, 362–63 Collisions, 54 Collocation services, 365–67 concept, 366 defined, 365–66 selection consideration, 366–67 See also Recovery sites Common open policy serve (COPS), 350–51 Communications management, 324 Compact packet-switching backplane (CPSB), 188 CompactPCI, 188 Complexity, 27–28 Configuration management, 193, 324 Congestion management, 336–38 Constraint-based routing (CBR), 91 Containment, 11 Content delivery networks (CDNs), 146–49 advantages, 146 defined, 146 elements, 146 enterprise (ECDNs), 148 example, 147 offerings, 148–49 public, 146–47, 148 switching, 147 See also Caching Contingencies, 13–14 defined, 13 purpose, 13–14 Continuous backups, 246 Cookie redirection, 129 401 Cooling, 315–16, 320 Copper cable plant, 296–99 attenuation, 297 attenuation-to-cross talk ratio (ACR), 299 cross talk, 297–99 delay skew, 299 Gigabit Ethernet support, 297 noise, 297 parameters, 297–99 power-sum ACR (PSACR), 299 return loss, 297 See also Cable plant Corrosion, 308 Cost(s) component, 50–51 defined, 48 direct, 50 downtime, 49–50 indirect, 50–51 intangible, 51 metrics, 48–52 settlement, 50 CR-LDP, 347 Customer-relationship management (CRM), Cutover testing, 388 Cyclic redundancy check (CRC), 75 D Data network access, 162–67 logical link, 163–65 physical, 165–67 See also Network access Data replication, 234–37 defined, 234 file, 237–38 hardware-based, 236–37 journaling, 242 mirroring, 238–42 shared disk, 237 software-based, 235–36 strategies, 237–42 summary, 283 Data restoration/recovery, 279–83 defined, 34 point-in-time, 280–81 process, 282–83 time to data (TTD), 281–82 Dead server rebuild, 246 Decentralization, 24–25 Delay, 55 Dense wave division multiplexing (DWDM), 166 402 Design(s), 28 balance, 23–25 centralization, 24 Design(s) (continued) complexity, 27–28 decentralization, 24–25 network scale, 25–27 partitioned, 23 principles, 22–28 Diagnostic management, 194 Differential backups, 247 Digital access cross-connect systems (DACS), 153 Digital data storage (DDS), 254 Direct attached storage device (DASD), 256 Disaster recovery See Recovery Disk systems, 247–48 DNS, 314 redirection, 128 services, 142–43 Downtime costs, 49–50 Dual-tone multifrequency (DTMF), 153 Duplexing, 54, 248 Duty cycle, 54 Dynamic hierarchical configuration protocol (DHCP), 82–83, 314 Dynamic reconfiguration, 195 Dynamic resource allocation, 190 E Edge topologies, 69 Electrolytic corrosion, 308 Electronic vaulting, 254–55 Element management system (EMS), 202–3 Enterprise CDNs (ECDNs), 148 Enterprise layout, 289–91 facility, 291 facility location, 290–91 network, 290 Enterprise resource planning (ERP), Enterprise SANs (E-SANs), 270–71 defined, 270 illustrated, 271 objectives, 270–71 Environmental strategies, 315–19 air/cooling, 315–18 fire protection, 318–19 See also Facilities Error(s), 11–12 cause, 58 intermittent, 11 rates, 57 Index self-healing, 11 simplex, 11 Ethernet, 74–76 best-effort principle, 74 cyclic redundancy check (CRC), 75 defined, 74 fast, 75, 80 frames, 74 hubs, 74 metro, 104–6 problem categories, 75 problems, 75–76 QoS and, 346 See also Local area networks (LANs) Event management, 193 Exponential networks, 25 Exposure metrics, 47 Extended copy, 257 Exterior gateway protocols (EGPs), 91 F Facilities, 289–320 cable plant, 291–301 enterprise layout, 289–91 environmental strategies, 315–19 layout, 291 location, 290–91 power plant, 301–15 summary, 319–20 Failover, 12–13 automatic, 370 cluster, 119–20 cold, 12, 119 defined, 12 granularity, 195 hot, 12, 119 illustrated, 13 management, 194 platforms, 179–80, 189–91 preemptive, 12 station, 155 transparent, 370 types, 12, 13 warm, 12, 119 Failure frequency of, 41 probability, vs network size, 40 rate, 37–38 False redundancy, 15–16 Fast Ethernet, 80 Fault management, 193–95 alarm management, 194 Index application manager, 193 automation, 193 checkpoint management, 194 configuration management, 193 diagnostic management, 194 event management, 193 failover management, 194 system logging, 194–95 Fault mechanics, 9–14 containment, 11 contingency, 13–14 disruptions, 10–11 errors, 11–12 failover, 12–13 illustrated, 10 recovery, 13 resumption, 14 Fault resilience (FR), 22 defined, 22 platform, 184 Fault tolerance (FT), 21–22 achieving, 22 criteria, 21 defined, 21 platform, 182–84 Fault-tolerant systems, 116 Fiber-optic cable plant, 299–301 advantages, 300 bandwidth, 300 chromatic dispersion (CD), 301 cross talk, 300 drift, 300 fiber loss, 300 four-wave mixing, 301 optical noise, 300 optical TDR (OTDR) devices, 300 parameters, 300–301 point loss, 300 polarization-mode dispersion (PMD), 301 reflectance, 300 See also Cable plant Fibre Channel, 261–66 arbitrated loop topology, 263 connectivity, 266 defined, 261 development, 261 dual arbitrated loop topology, 264 file transfers, 261 five-layer model, 265–66 frames, 262 migrating to, 266 over IP (FCIP), 272 403 point-to-point topology, 262 routers, 264 switched fabric topology, 265 use of, 266 See also Storage area networks (SANs) File replication, 237–38 Fire protection, 318–19 Form factors, 189 Forwarding equivalence classes (FECs), 99 Forward proxy, 144–45 Frame relay, 83–85 backup link use, 84 defined, 83 IP and, 97 problems, 84 WAN planning, 84 See also WAN technologies Free space optics (FSO), 171–72 Freshness window, 35 Full backups, 244–45 Functional tests, 374 G Gas discharge tube (GDT), 305 Generators, 311–12 Geosynchronous-Earth-orbit (GEO) satellites, 173 Gigabit Ethernet, 77, 80 Global load balancing, 127 Goodput, 58 Grounding, 307 Guiding principles, 393–95 H Hardened drivers, 192 Hardware architectures (network), 198–201 backplanes, 199–200 clocking, 200 dual controllers, 200 generic functions, 199 hot swapping, 201 interface modules, 200 modularity, 199 port architecture and density, 200–201 standards compliance, 201 Hardware architectures (server), 186–91 backplanes, 186–87 buses, 187–88 form factors, 189 platform failover, 189–91 See also Server platforms 404 Hardware-based replication, 236–37 Hierarchical storage management (HSM), 274–75 High availability (HA), 22 defined, 22 platform, 184 Host bus adapters (HBAs), 257 Hosting dedicated, 365 managed, 365 services, 364–65 shared, 365 Hot failover, 12, 13 Hot sites, 360–62 defined, 360 development recommendations, 361–62 service providers, 361 See also Recovery sites Hot standby routing protocol (HSRP), 94–95 Hot swapping, 201 Hubs, 74 Hypertext markup language (HTML), 132 Index SLAs, 139 transmit arrangements, 142 Interworking, 132–43 Inverse multiplexing, 164 I/O handling, 196–98 IP storage, 271–73 FCIP, 272 iSCSI, 272–73 on-line, 271–72 See also Storage IP telephony, 156–58 phones, 158 softswitch technology, 157 VoIP architectures, 158 VoIP gateways, 158 See also Voice network access iSCSI, 272–73 J Jitter, 56 Journaling, 242 K I Impedance mismatch, 54 Incremental backups, 245–46 Infiniband, 188, 267–68 bus, 268 defined, 267–68 SANs, 268 Integration testing, 380–81 defined, 380 top-down, 381 types of, 380–81 See also Testing Intelligent route control (IRC), 91 Intelligent voice response (IVR), 158–59 Interactive Services Association (ISA) bus, 187 Interframe gap, 74 Interior gateway protocols (IGPs), 91 Intermittent errors, 11 Internet access, 139–43 diverse example, 141 DNS services, 142–43 ISP, 140–41 peering and exchanging, 141–42 Internet service providers (ISPs) access, 140–41 peering arrangements, 141 performance, 142 POP, 140–41 RAS, 140 KN redundancy, 16–17 advantages/disadvantages, 17 defined, 16–17 example, 17 illustrated, 16 See also Redundancy L Label switching routers (LSRs), 99 Latency, 55–57 contributors, 55–56 defined, 55 propagation, 56 real-time, 57 zero, 55 See also Performance metrics Life cycle costs, Lightning protection, 306–7 Line conditioning devices, 305 Load balancers appliances, 129 caveats, 131–32 classifications, 124 clusters and, 124–25 component, 124 defined, 123 with multitier Web sites, 131 network, 124 server switching, 130 Index software-based, 129–30 switch-based, 130 switch farms, 130–31 technologies, 129–31 Load balancing, 123–32 cookie redirection, 129 defined, 123 DNS redirection, 128 examples, 124 global, 127 local, 126–27 with multitier Web site, 125 redirection methods, 125–28 SSL considerations, 128–29 summary, 149 switch farm example, 131 Load-sharing routers, 164–65 Load testing, 384–85 approaches, 385 defined, 384–85 purposes, 385 Local area networks (LANs), 73–83, 108 backbone switching, 77 DHCP, 82–83 Ethernet, 74–76 link redundancy, 78 media translators, 80 multilayer switching, 78 network adapter techniques, 80–82 network interface cards (NICs), 80–82 QoS and, 347 shared, 76 switched, 76–77 transceivers, 79–80 virtual (VLANs), 78–79 wireless (WLANs), 169 See also Networking technologies Local directory application protocol (LDAP), 351 Local load balancing, 126–27 Logical link access, 163–65 hard outages, 163 inverse multiplexing, 164 link aggregation, 163–65 load-sharing routers, 164–65 soft outages, 163 Loosely coupled architectures, 182, 183 Loss, 57 Low-Earth-orbit (LEO) satellites, 172 M Man-Machine Language (MML), 203 405 Mean time between failure (MTBF), 38–40 availability vs., 43 defined, 38 example, 39 low, 39 variants, 40 See also Reliability metrics Mean time between service interruptions (MTBI), 40 Mean time to data availability (MTDA), 40 Mean time to data loss (MTDL), 40 Mean time to failure (MTTF), 37 Mean time to recovery (MTTR), 38 effect on availability, 45 high, 44 Media translators, 80 Medium-Earth-orbit (MEO) satellites, 173 Mesh topologies, 65–66 constrained, 66 flat, 66 full, 65 See also Topologies Metal oxide varistor (MOV), 305 Metcalfe’s Law, 26 Metrics, 31–60 availability, 42–47 bandwidth, 53 capacity, 52–54 computing, 31–32 cost, 48–52 defined, 31 error, 57–58 exposure, 47 failure rate, 37–38 latency, 55–57 loss, 57 MTBF, 38–40 MTTF, 37 MTTR, 38 overhead, 54 performance, 55–59 performance testing, 383–84 recovery, 32–36 recovery time components, 34–35 reliability, 40–42 response time, 57 risk/loss, 47–48 RPO, 35–36 RTO, 32–33 summary, 59–60 tailoring, 31 throughput, 58–59 406 Metrics (continued) utilization, 52–53 Metro Ethernet, 104–6 defined, 104 reroute, 105 Metropolitan area networks (MANs), 103–8, 109 defined, 104 metro Ethernet, 104–6 RPR, 106–8 See also Networking technologies Microwave, 169–71 limitations, 170 point-to-point backbones, 170 popularity, 169 redundant transmitter-receiver system, 171 SONET interoperability with, 170 See also Wireless access Mirroring, 238–42 asynchronous data transfer, 241–42 defined, 238 with disk arrays, 239 example, 238 file replication vs., 239 hardware-based, 238–39 remote, 238 software-based, 238, 239 synchronous data transfer, 240–41 See also Data replication Mission critical applications, 210 defined, 1–2 planning, case for, 4–5 platforms, 177–207 Mission goals/objectives, 6–7 application performance, downtime, life cycle costs, network performance, time to value, Mobile sites, 363 Multilayer WAN switching, 96–101 ATM and SONET, 97–99 IP and ATM, 97 IP and frame relay, 97 MPLS, 99–100 SNA, 100–101 Multilink PPP (MLP), 165 Multipath label switching (MPLS), 99–100 defined, 99 FECs, 99 LSRs, 99 Index planning, 340–41 routing example, 100 VPNs, 103 Multiple tenant units (MTUs), 293–95 cable example, 293 intermediate ICs, 293 mission-critical, 294 See also Cable plant Multiprocessor clusters, 116 N Net effect, 25–26 Network access, 153–75 data, 162–67 summary, 173–75 voice, 153–62 wireless, 167–73 Network access points (NAPs), 141 Network-attached storage (NAS), 268–70 benefits, 269 defined, 268 devices, 268–69 illustrated, 268 SANs and, 269–70 Network continuity access, 153–75 defined, disaster recovery vs., 2–4 facilities, 289–320 metrics, 31–60 network management for, 323–56 principles, 9–28 software application, 209–28 storage, 231–85 technologies for, 73–109 testing, 373–91 topologies and, 63–70 Network continuity planning, fault mechanics, 9–14 as practice, trends affecting, 5–6 Networked storage, 256–73 enterprise SANs, 270–71 IP, 271–73 NAS, 268–70 SANs, 257–68 topologies, 256 See also Storage Network hops, 56 Networking technologies, 73–109 LANs, 73–83 MANs, 103–8 Index summary, 108–9 WANs, 83–103 Network interface cards (NICs), 80–82 bottlenecks, 82 defined, 80 multiport, 81 for redundancy, 81 Network management, 323–56 analysis results, 331 carrier/supplier, 333–34 change, 353–54 communications, 324 configuration, 324 corrective action, 330 event correlation, 329 event detection, 328–29 migrating, to the enterprise, 323–25 monitoring, 326–28 policy-based, 348–51 problem categories, 331 problem isolation, 329 problem resolution, 328–31 QoS, 342–48 restoration, 331–32 root cause analysis, 329–30 security, 324 service-level, 341–42 SLAs, 351–53 software, 324 summary, 354–56 system, 324 topology discovery, 325–26 traffic, 334–41 Network monitoring, 326–28 device focus, 327 proactive systems, 327–28 tracking/trending, 328 transaction rate sampling, 327 Network platforms, 198–202 hardware architectures, 198–201 operating systems, 201–2 Network recovery See Recovery Network scale, 25–27 N + k redundancy, 18 defined, 18 example, 19 illustrated, 18 N + k with kN redundancy, 18–20 defined, 18 illustrated, 19 See also Redundancy 407 O On-line storage, 271–72 Open shortest path first (OSPF), 91, 92–93, 164 defined, 92 example, 92 features, 93 Operating systems (OSs), 181 application interaction, 223–24 network platform, 201–2 Operational support systems (OSSs), 157 Optical TDR (OTDR) devices, 300 Organization, this book, 7–8 Overhead, 54 P Packet wrapping, 107 Parity, 248–49 Parity drives, 249 Partitioning, 23, 190 Path diversity, 160–61 Peering, 141–42 arrangements, 141 points, 56, 141 Peer-to-peer topologies, 69–70 Performance application, envelope, 4, 10 ISP, 142 network, tape system, 252–53 Performance metrics, 55–59, 383–84 error, 57–58 latency, 55–57 loss, 57 response time, 57 throughput, 58–59 See also Metrics Performance testing, 382–84 goal, 382 metrics, 55–59, 383–84 passing, 384 test capabilities, 382–83 See also System testing; Testing Peripheral component interconnect (PCI) bus, 187–88 Personal communication services (PCS), 167–68 Physical access techniques, 165–67 Physical vaulting, 254 Platform recovery See Recovery 408 Platforms, 177–207 application interaction, 222–24 certifications, 180 comparisons, 185 CPU, 180 critical characteristics, 177–81 drivers, 179 economy, 178 EMS, 202–3 equipment cooling, 178 equipment density, 178 equipment ventilation, 178–79 failover, 179–80 fault resilience, 184 fault tolerance, 182–84 Platforms (continued) FT/FR/HA, 189–90 functionality, 180 high availability, 184 maintenance, 203–5 management, 202–5 memory, 179 multiprocessor, 204 network, 198–202 openness, 180 options, 181 OS, 181 power management, 205–6 quality, 180 redundancy, 179 server, 185–97 serviceability, 179 simplicity, 178 split-mode operation example, 204 storage, 180 swappability, 179 tolerance, 181–85 upgrade ability, 181 Plesiochronous digital hierarchy (PDH), 97 Point-in-time recovery, 280–81 Point of presence (POP), 140–41 Point-to-point tunneling protocol (PPTP), 103 Policy-based network management (PBNM), 348–51 defined, 348 functions, 350 illustrated, 349 implementing, 350 tools, 349 Port mirroring, 77 Power backup, 308–12 Index independent feeds, 206 irregularities, 302–3 line conditioning, 206 load-sharing, 206 management, 205–6, 314–15 public, 304 quality, 304–12 redundant supplies, 205 secure control, 206 supply, 303–4 Power-conditioning devices, 304 Power distribution units (PDUs), 312–14 Power fail transfer (PFT) systems, 312 Power plant, 301–15 2N distribution architecture, 313 backup power, 308–12 corrosion, 308 distribution architecture, 312–14 grounding, 307 lightning protection, 306–7 power management, 314–15 summary, 320 surge protection, 305–6 Pressure testing See Load testing Preswitch offload, 166 Private branch exchanges (PBXs), 154–56 alternative backup services, 156 backstage storage, 156 call reroute, 155–56 informative announcements, 156 multihomed stations, 155 power protection, 155 remote diagnostics, 156 remote switch modules, 155 spare components, 156 station failover, 155 with survivability features, 154 system redundancy, 154–55 See also Voice network access Protocol analyzers, 389 Protocols, 70–71, 72 number, reducing, 70 overhead, 54 survivability strategies, 70–71 Public power, 304 Purpose, this book, Q QoS, 342–48 ATM and, 347–48 benefits, 342 in caching devices, 346 Index CR-LDP and, 347 defined, 342 deployment, 345–46 Ethernet and, 346 fair bandwidth, 345 guaranteed delivery, 345 LAN/WAN and, 347 in load balancers, 346 marking, 343 policing, 343–44 queuing, 344 random early detection (RED), 344–45 in routers, 346 RSVP and, 347 SONET and, 348 stages, 342–45 strategies, 346–48 streaming services and, 348 TCP rate shaping, 344 traffic classification, 342–43 in traffic shapers, 345–46 R RAID, 248–51 array controllers, 248 defined, 248 drawback, 251 duplexing, 248 implementation, 249 level (RAID 0), 249 level (RAID 1), 249–50 level (RAID 2), 250 level (RAID 3), 250 level (RAID 4), 250 level (RAID 5), 250 level 10 (RAID 10), 250–51 parity, 248–49 striping, 248 See also Storage Random early detection (RED), 344–45 Rapid ring spanning tree (RRST), 106 Recovery activities, 13 application, 34 data, 34 defined, 3, 13 network, 34 network continuity vs., 2–4 operations, 370–71 platform, 34 resources, 368 service, 34 409 service providers, 255 Recovery metrics, 32–36, 59 recovery time components, 34–35 RPO, 35–36 RTO, 32–33 Recovery point objective (RPO), 35–36 defined, 35 RTO vs., 36 using, 36 Recovery sites, 359–71 cold, 362–63 collocation services, 365–67 hosting services, 364–65 hot, 360–62 implementing, 368–69 mobile, 363 network example, 369 networking, 369–70 recovery operations, 370–71 recovery services, 367 selection considerations, 363–64 service provider options, 365 services, 363–67 summary, 371 types of, 359–63 warm, 363 Recovery time objective (RTO), 32–33 applying, 32 defined, 32 loss and cost vs., 33 RPO vs., 36 Redirection cookie, 129 DNS, 128 methods, 125–28 traffic, 370 Redundancy, 28 defined, 14 diversity, 16 false, 15–16 kN, 16–17 N + k, 18, 19 N + k with kN, 18–20 operating costs and, 14 principles, 11, 14–20 single points of failure and, 14–16 types of, 16–20 Redundant array of independent disks See RAID Relational database-management systems (RDBMSs), 234 410 Reliability availability vs., 36 block diagrams (RBD), 41–42 defined, 36 function, 41 improvement cost, 47 Reliability metrics, 36–42, 59 failure rate, 37–38 MTBF, 38–40 MTTF, 37 MTTR, 38 reliability, 40–42 Remote access servers (RAS), 140 Replication, 234–42 asynchronous, 241–42 defined, 234 file, 237–38 hardware-based, 236–37 journaling, 242 mirroring, 238–42 shared disk, 237 software-based, 235–36 strategies, 237–42 summary, 283 synchronous, 240–41 Resilient packet ring (RPR), 106–8 defined, 106 packet wrapping, 107 steering, 107 traffic failover example, 107 Resilient packet transport (RPT), 108 Resource reservation protocol (RSVP), 341, 347, 350 Response time, 57 Restart/masking, 195–96 Restoration management, 331–32 containment, 331–32 contingency, 332 defined, 331 notification, 332 repair, 332 resumption, 332 Resumption, 14 Ring topologies, 65, 67–68 counterrotating, 67 defined, 67 expense, 67–68 stranded capacity, 68 See also Topologies Risk-based testing, 386–87 Risk/loss metrics, 47–48 Rolling window, 12 Index Route optimization, 95–96 Routing information protocol (RIP), 91–92 defined, 91 example, 92 uses, 91 S SAN management, 275–79 application integration support, 276 capacity monitoring, 276–77 cross-platform integration, 276 device pooling, 275–76 device zoning, 275 scalability, 276 security, 276 sharing control, 275 virtualization, 277–79 See also Storage management Satellites, 172–73 GEO, 173 LEO, 172 MEO, 173 VSAT, 172 Scale-free networks, 25 SCSI, 266–67 defined, 266 evolution, 267 limitations, 267 uses, 267 Secure code reviews, 210 Secure socket layer (SSL), 128–29 Security management, 324 Self-healing environments, Self-healing errors, 11 Server clusters, 116 Serverless backups, 257 Server platforms, 185–97 hardware architectures, 186–91 mix of capabilities, 185 software architecture, 191–97 Server switching, 130 Service-level agreements (SLAs), 216, 351–53 carrier, 352–53 defined, 351 external, 351–52 internal, 352 Service-level management (SLM), 341–42, 355 Service recovery See Recovery Shared disk, 237 Signaling system (SS7), 157 Signaling transfer points (STPs), 157 Silicon avalanche diode (SAD), 305 Index Simple network management protocol (SNMP), 219, 325, 351, 355 Simplex errors, 11–12 defined, 11 rolling window, 12 Single points of failure, 14–16 defined, 14 as serial path of multiple elements, 15 Slow time, 10 Software application continuity, 209–28 Software architecture (server), 191–97 dynamic reconfiguration, 195 fault management, 193–95 generic, 192 I/O handling, 196–98 restart/masking, 195–96 See also Server platforms Software-based replication, 235–36 Software development, 210–14 APIs, 214 certification and, 213–14 defined, 210 middleware, 214 for mission-critical applications, 212 modularization, 213 operations/maintenance and, 214 portability and, 213 process, 211 requirements and, 213 secure code reviews, 210 See also Applications Software management, 324 SONET, 86–89 add-drop multiplexers (ADMs), 153 APS protection scenarios, 87 ATM and, 97–99 dedicated protection schemes, 87–88 defined, 86 Ethernet mapping and, 89 microwave interoperability, 170 optical layer survivability, 89 optimization, 88 protection path, 86 provisioning systems, 86 QoS and, 348 rings, 86, 88, 98–99 thrashing, 98 See also WAN technologies Storage, 231–85 backup strategies, 242–47 component questions, 232–34 data replication, 234–42 411 disk systems, 247–48 mission-critical requirements, 231–34 networked, 256–73 on-line, 271–72 RAID, 248–51 SAN-attached, 257 services, 255–56 summary, 283–85 systems, 247–54 tape systems, 251–54 tunneling, 272 vault services, 254–55 virtualization, 277–79 See also SAN management Storage area networks (SANs), 257–68 attached storage (SAS), 257 benefits, 260 defined, 257 design, 258 directors, 257 effective use of, 259 enterprise (E-SANs), 270–71 entry costs, 260 Fibre Channel, 261–66 InfiniBand, 267–68 limited interoperability, 260 NAS and, 269–70 nodes, 258 SCSI, 266–67 storage devices, 257 Sysplex (S-SANs), 261 topologies, 258 Storage management, 273–83 characteristics, 273–74 cross-platform support, 274 data integrity, 274 data location, 274 data restoration/recovery, 279–83 desktop/mobile data, 274 hierarchical, 274–75 multiple data replica, 273 reporting, 274 SAN, 275–79 storage capacity, 274 Storage service providers (SSPs), 255–56 Stranded capacity, 68 Streaming services, 348 Stress testing See Load testing Striping, 248 Structural tests, 374 Surge protection devices (SPDs), 305–6 Switch farms, 130–31 412 Switching, 76–77 automatic protection (APS), 87 backbone, 77 CDN, 147 layer 2, 77 multilayer LAN, 78 multilayer WAN, 96–101 server, 130 Synchronous data transfer, 240–41 Synchronous digital hierarchy (SDH), 86 System logging, 194–95 System management, 324 System network architecture (SNA), 100–101 System testing, 381–87 backup/recovery, 385–86 defined, 381 load, 384–85 performance, 382–84 tactical, 386–87 See also Testing T Tactical testing, 386–87 Tape systems, 251–54 characteristics, 251–52 DAT, 254 DDS, 254 DLT, 253 helical scan, 253 magnetic tape, 251 performance, 252–53 technology, 253–54 See also Storage Telnet, 351 Testing, 373–91 acceptance, 387–88 backup/recovery, 385–86 cutover, 388 element-to-element, 380 end-to-end, 380 end-to-end interconnection, 381 environment, 375, 377–78 environment pitfalls, 378 host-based, 374 importance of, 373 integration, 380–81 interconnection, 380 intersystem, 380 load, 384–85 outboard, 374 performance, 382–84 phases, 378–90 Index process, 375, 376 requirements and, 374–75 stages illustration, 379 summary, 390–91 system, 381–87 tactical, 386–87 troubleshooting, 388–90 unit, 380 Tests functional, 374 planning, 375–77 structural, 374 throwaway, 374 Throughput, 52, 58–59 estimating, 58 illustrated, 59 Tiered topologies, 68 Tightly coupled architectures, 182, 183 Time to data (TTD), 281–82 Time to live (TTL), 143 Tolerance, 28 availability vs., 20–21 defined, 20 fault (FT), 21–22, 182–84 fault resilience (FR), 22, 184 high availability (HA), 22, 184 platform, 181–85 principles, 20–22 Topologies, 63–70 bus, 64 discovery, 325–26 edge, 69 fundamental, 64–65 illustrated, 65 logical, 63 mesh, 65–66 multipoint, 65 peer-to-peer, 69–70 physical, 63 point-to-point, 64 ring, 65, 67–68 star, 65 tiered, 68 Traffic, 355 capacity planning, 338–41 classifying, 334–35 congestion management, 336–38 control, 335–36 management, 334–41 redirection, 370 shapers, 345–46 shaping, 336, 337–38 Index 413 See also Network management Transceivers, 79–80 Transient voltage surge suppressors (TVSS), 305 Troubleshooting testing, 388–90 comprehensive, 388–89 defined, 388 with protocol analyzers, 389 steps, 389–90 See also Testing Voice network access, 153–62 carrier services, 159–62 IP telephony, 156–58 IVR, 158–59 PBXs, 154–56 See also Network access Voice over IP (VoIP), 157 architectures, 158 gateways, 158 next generation, 174 U W Uninterruptible power supply (UPS), 308–10 battery, 309 defined, 308 line-interactive, 310 on-line, 310 redundant, 310 standby, 309 types, 309 Unit testing, 380 Uptime, 11 Utilization, 52–53 defined, 52 illustrated, 53 See also Capacity WAN routing, 90–96 BGP, 93–94 HSRP, 94–95 optimization techniques, 95–96 OSPF, 92–93 RIP, 91–92 VRRP, 94–95 See also Wide area networks (WANs) WAN technologies, 83–90 ATM, 85–86 frame relay, 83–85 SONET, 86–89 WDM, 89–90 See also Wide area networks (WANs) Warm failover, 12, 13 Warm sites, 363 Wave division multiplexing (WDM), 89–90 Web site(s), 149–50 architecture, 135–36 browser versions and, 133 bursty traffic and, 133 coding, 136 content, 136 design, 133, 135–37 graphics, 133 implementation approaches, 135 linking, 136 multitiered, 135 navigation, 137 performance management, 132–35 performance monitoring, 134–35 recovery examples, 138 recovery management, 137–39 slowdowns, 133 SSL connections, 133 Wide area clusters, 122–23 Wide area networks (WANs), 83–103, 108–9 access architecture example, 101 defined, 83 design strategies, 101–2 V Versa module europa (VME), 188 Very small aperture terminal (VSAT) systems, 172 Virtualization, 277–79 application awareness of, 279 complexity, 279 defined, 277 inband, 279 techniques, 278 See also Storage Virtual LANs (VLANs), 78–79 backbone traffic, 79 defined, 78–79 on same physical switch, 79 Virtual private networks (VPNs), 102–3 defined, 102 MPLS, 103 over Internet, 103 as WAN backup, 104 Virtual router redundancy protocol (VRRP), 95 Virtual storage access method (VSAM), 234 Voice mail systems, 158–59 414 Wide area networks (WANs) (continued) multilayer switching, 96–101 QoS and, 347 routing methods, 90–96 technologies, 83–90 uptime guarantee, 102 usage basis redundancy, 102 VPNs, 102–3 See also Networking technologies Wire center diversity, 160 Wireless access, 167–73 broadcast, 172 cellular/PCS, 167–68 free space optics (FSO), 171–72 functioning of, 167 microwave, 169–71 satellite, 172–73 wireless LAN, 169 See also Network access Wireless LANs (WLANs), 169 Index .. .Mission- Critical Network Planning For a listing of recent titles in the Artech House Telecommunications Library, turn to the back of this book Mission- Critical Network Planning Matthew... Liotine, Matthew Mission- critical network planning — (Artech House telecommunications library) Computer networks—Design and construction Business enterprises—Computer networks I Title 004.6 ISBN 1-58053-516-X... 1.6 1.7 What Is Mission Critical? Purpose of the Book Network Continuity Versus Disaster Recovery The Case for Mission- Critical Planning Trends Affecting Continuity Planning Mission Goals and