Architecture of Network Systems This page intentionally left blank Architecture of Network Systems Dimitrios Serpanos Tilman Wolf AMSTERDAM (cid:129) BOSTON (cid:129) HEIDELBERG (cid:129) LONDON NEW YORK (cid:129) OXFORD (cid:129) PARIS (cid:129) SAN DIEGO SAN FRANCISCO (cid:129) SYDNEY (cid:129) TOKYO Morgan Kaufmann Publishers is an imprint of Elsevier AcquiringEditor:ToddGreen EditorialAssistant:RobynDay ProjectManager:AndreCuello Designer:KristenDavis MorganKaufmannisanimprintofElsevier 30CorporateDrive,Suite400,Burlington,MA01803,USA #2011Elsevier,Inc.Allrightsreserved. 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Notices Knowledgeandbestpracticeinthisfieldareconstantlychanging.Asnewresearchandexperience broadenourunderstanding,changesinresearchmethodsorprofessionalpracticesmaybecome necessary.Practitionersandresearchersmustalwaysrelyontheirownexperienceandknowledgein evaluatingandusinganyinformationormethodsdescribedherein.Inusingsuchinformationor methodstheyshouldbemindfuloftheirownsafetyandthesafetyofothers,includingpartiesfor whomtheyhaveaprofessionalresponsibility. Tothefullestextentofthelaw,neitherthePublishernortheauthors,contributors,oreditorsassume anyliabilityforanyinjuryand/ordamagetopersonsorpropertyasamatterofproductsliability, negligenceorotherwise,orfromanyuseoroperationofanymethods,products,instructions,orideas containedinthematerialherein. LibraryofCongressCataloging-in-PublicationData Serpanos,DimitriosNikolaou. Architectureofnetworksystems/DimitriosSerpanos,TilmanWolf. p.cm.– (TheMorganKaufmannseriesincomputerarchitectureanddesign) Includesbibliographicalreferencesandindex. ISBN978-0-12-374494-4(pbk.) 1. Computernetworkarchitectures. I.Wolf,Tilman.II.Title. TK5105.5.S42342011 004.6–dc22 2010045063 BritishLibraryCataloguing-in-PublicationData AcataloguerecordforthisbookisavailablefromtheBritishLibrary. ISBN:978-0-12-374494-4 PrintedintheUnitedStatesofAmerica 11 12 13 14 10 9 8 7 6 5 4 3 2 1 ForinformationonallMKpublicationsvisitourwebsiteatwww.mkp.com To the memory of my father Nikolaos. -DS To Ana and our daughter Susana. -TW This page intentionally left blank Contents Preface................................................................................................................. xiii About the Authors.............................................................................................. xvii CHAPTER 1 Architecture of network systems overview............................. 1 Computer networks...................................................................... 1 Embedded systems....................................................................... 3 Protocols and network systems.................................................... 5 Organization of this book............................................................ 6 CHAPTER 2 Network protocols and network systems.............................. 11 Introduction................................................................................. 11 The open systems interconnection reference model................. 12 Protocol stacks and protocol elements...................................... 13 Network systems: Definition and types..................................... 17 Structure of network systems..................................................... 21 Summary..................................................................................... 24 CHAPTER 3 Requirements of network systems....................................... 25 Introduction................................................................................. 25 Requirements of network applications and services................. 26 Qualitative requirements.......................................................... 27 Quantitative requirements........................................................ 27 Example requirements.............................................................. 28 The throughput preservation challenge..................................... 29 Traffic models and benchmarks................................................. 32 Summary..................................................................................... 33 CHAPTER 4 Interconnects and switching fabrics.................................... 35 Introduction................................................................................. 35 Crossbars and interconnection networks................................... 38 Switch organization.................................................................... 40 Switch scheduling....................................................................... 43 Centralized scheduling............................................................. 46 Distributed scheduling.............................................................. 49 Use of randomization............................................................... 57 Real-time traffic....................................................................... 61 Summary..................................................................................... 61 vii viii Contents CHAPTER 5 Network adapters............................................................... 63 Introduction................................................................................. 63 Basic network adapter................................................................ 64 Adapter operation analysis......................................................... 66 Memory organization................................................................. 70 Memory management unit with local memory....................... 70 Memorymanagementunitandprocessorwithlocalmemory... 73 Intelligent DMA......................................................................... 75 Multiprocessor processing element............................................ 77 Single SPE configuration......................................................... 79 Multi-SPE configuration—protocol multiprocessing.............. 80 Multi-SPE configuration—spatial parallelism......................... 81 Memory management schemes.................................................. 84 Detached MMU........................................................................ 86 Distributed MMUs.................................................................... 87 Summary..................................................................................... 87 CHAPTER 6 Bridges and layer 2 switches............................................. 89 Introduction................................................................................. 89 Types of bridges......................................................................... 91 Transparent bridging and special-purpose subsystems............. 92 High-performance transparent bridge architecture.................... 97 Transparent bridging support unit.......................................... 101 Network attachment unit design............................................ 104 lnternal switching component operation................................ 107 Partitioned data memory organization................................... 109 Layer 2 switches..................................................................... 110 Summary................................................................................... 110 CHAPTER 7 Routers............................................................................ 111 Network layer........................................................................... 111 Functionality of the network layer........................................ 111 Systems requirements............................................................. 112 Generic router design............................................................. 115 Data plane................................................................................. 117 Route lookup.......................................................................... 118 Queuing and buffering management...................................... 126 Control plane............................................................................ 129 Routing algorithms................................................................. 129 Error handling......................................................................... 136 Example network layer systems.............................................. 139 Summary................................................................................... 140 Contents ix CHAPTER 8 Transport layer systems................................................... 141 Transport layer.......................................................................... 141 Functionality of the transport layer....................................... 141 Network flows........................................................................ 143 Packet classification............................................................... 147 Transport layer systems.......................................................... 156 Summary................................................................................... 160 CHAPTER 9 Application layer systems................................................. 161 Application layer...................................................................... 161 Functionality of the application layer.................................... 162 Application layer protocols.................................................... 163 Network system support for application layer........................ 172 Payload inspection.................................................................. 172 Load balancing....................................................................... 180 Summary................................................................................... 182 CHAPTER 10 Quality of service and security......................................... 183 Cross-layer issues..................................................................... 183 Quality of service..................................................................... 183 Quality of service concepts.................................................... 184 Network support for QoS....................................................... 187 Link scheduling algorithms.................................................... 188 Quality of service summary................................................... 199 Security..................................................................................... 199 Security concepts.................................................................... 199 Cryptography overview.......................................................... 200 Security in network protocols................................................ 204 Denial-of-service attacks........................................................ 207 Summary................................................................................... 210 CHAPTER 11 Specialized hardware components.................................... 211 Hardware support for packet forwarding................................ 211 General-purpose packet processors.......................................... 211 Performance vs flexibility...................................................... 212 Systems-on-a-chip.................................................................. 213 Network processors................................................................ 214 Design choices........................................................................ 220 Example systems.................................................................... 223 Special-purpose hardware accelerators.................................... 224 Trade-offs in use of accelerators........................................... 224 Example accelerators.............................................................. 225