TCP/IP Illustrated, and ongoing series covering the many facets of TCP/IP, brings a highly-effective visual approach to learning about this networking protocol suite.
TCP/IP Illustrated, Volume 2: The Implementation contains a thorough explanation of how TCP/IP protocols are implemented. There isn't a more practical or up-to-date book-this volume is the only one to cover the de facto standard implementation from the 4.4BSD-Lite .release, the foundation for TCP/IP implementations run daily on hundreds of thousands of systems worldwide.
Introduction
This book describes and presents the source code for the common reference implemrntation of TCP/IP: the implementahon from the Computer Systems Research Group (CSRG) at the University of California at Berkeley Historically this has been distributed with the 4.x BSD system (Berkeley Software Distrthetion). This implementation was first released in l982 and has survived many significant changes, much fine tuning, and numerous ports to other Unix and non-Unix systems. This is not a toy implementahon,but the foundation for TCP/IP implementations that are run daily on hundreds of thousands of systems worldwide. This implementation also provides router fUnctionality,lethng us show the differences between a host implementation of TCP/IP and a routeL
We describe the implementation and present the entire source code for the kerneI implementation of TCP/IP, approximately l5,00() lines of C code. The version of the Berkeley code described in this text is the 4.4BSD-Lite release. This code was made publicly available in April l994, and it contains numerous networking enhancements that were added to the 4.3BSD Tahoe release in l988, the 4.3BSD Reno release in 1990, and the 4.4BSD release in 1993. (Appendix B describes how to obtain this source code.) The 4.4BSD release provides the latest TCP/IP features, such as multicasting and long fat piPe support (for high-bandwidth, long-de1ay paths). Figure l.l (p. 4) provides additional details of the various releases of the Berkeley networking code.
This book is intended fOr anyone wishing to understand how the TCP/IP protocols 4re implemented: programmers writing network applications, system administrators responsible for maintaining computer systems and networks utilizing TCP/IP, and any programmer interested in understanding how a large body of nontrivial code fits into a real operating system.
Organization of the Book
The following figure shows the various protocols and subsyst6ms that are covered. T'he italic numbers by each box indicate the chapters in which that topic is described.We take a bottom-up approach to the TCP/IP protocol suite, starhng at the data-link layer, then the netWork layer (IP, ICMP, IGMP, lP routing, and mulhcast routing), followed by the socket layer, and trishing with the transPort layer (UDP, TCP, and raw IP).
Intended Audience
This book assuznes a basic understanding of how the TCP/IP protocols work. Readers unfamiliar with TCP/lP should consult the first volume in this series, lStevens 1994],for a thorough description of the TCP/IP protocol suite. This earlier volume is referred to throughout the current text as V0Iume 1. The current text also assumes a basic understanding of operating system principles.
We describe the implementahon of the protocols using a data-structures approach.That is, in addition to the source code presentation, each chapter contains pictures and descriptions of the data structures used and maintained by the source code. We show how these data structUres fit into the other data structures used by TCP/lP and the kernel. Heavy use is made of diagrams throughout the text--there are over 250 diagrams.
This data-structures approach allows readers to use the book in various ways.Those interested in all the implementation details can read the entire text from start to finish, following through all the source code. Others might want to understand how the protocols are implemented by understanding all the data structures and reading all the t8xt, but not following through all the source code.
We anhcipate that man readers are interested in specilic portions of the book and will want to go directly tO those chapters. Therefore many fOrward and backward refer ences are provided throughout the text, a1ong with a thorough index, to allow individual chapters to be stUdied by themselves. T'he inside back covers contain an alphabetical cross-reference of all the funchons and macros described in the book and the starting page number of the description. Exercises are provided at the end of the chaptersJ most soluhons are in Appendjx A to maxAnize the usefUlness Of the text as a self stUdy reference.
Source Code CopyrIght
A1l of the source code presented in this book, other than Figures 1.2 and 827, is from the 4.4BSD-Lite distribuhon. ms software is publicly available through many sources(Appendix B).
Copyright (c) l982, l986, l988, 1990, l993, l994
The Regents of the University of Ca1ifornia. All rights reserved.
Redistribut1on and use in source and binary forns, with or without
modification, are pemitted provided that the following conditions are net:
1. Redistributions of source code rmst reta1n the above copyright notice. this list of conditions and the fo1lowing disclainer.
2. Redistributions in binary form must repr6duce the above copyright notice, this list of conditions and the fol1owing disclaimer in the, documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this 5oftware must display the fol1owing acknowledgement:This product inc1udes software deve1oped by the Un1versity of California, Berke1ey and its contributors.
4. Neither the name of the University nor the nanes of its contributors cay be used to endorse or promote products derived from this software without specific prior written permission.
THIS SQFunE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS' 'AS IS'' AND
ANy EXPRESS OR IMPLIED WARRANTIES. INCLUDING, BUT NOT LIMITED T0, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICUim ruRPOSE
ARE DISCLAIMED. IN N0 EVENT SHALL THE REGENTS 0R CONTRIBUTORS BE LIABLE
FOR ANY DIRECT. INDIRECT, INCIDanTAL, SPBCIAL, EXEMPLARY, 0R C0NSEQUarIAL
DAMAES (INCLUDING, BUT N0T LIMITED TO, PROCURBMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA. OR PR0FITS; OR BUSlNESS lNTERRUPTI0N)
H0WEVER CAUSED AND 0N AN'Y THEORY OF LIABILlTY, WHETHER IN C0NTRACT, STRICT
LIABILITY, OR T0RT (INCLUDING NEGLIGENCE OR 0THERWISE) ARISING IN un wny
OUT 0F THE USE OF THIS SOFTWARE. EVan IF ADVISBD OF THE POSSIBILITY 0F SUCH D AMAGE.
Acknowledgments
We thank the terhnical reviewers who read the manuscript and provided important feedback on a tight hmetable: Ragnvald Blindheim, Jon Crowcroft, Sally Floyd, Glen Glater, John Gulbenkian, Don Hering, Mukesh Kacker, Berry Kercheval, Brian W Kernighan, Ulf Kieber, Mark Laubach, Steven McCanne, Craig Partridge, Vern Paxson,Steve Rago, Chakravardhi Ravi, Peter Salus, Doug Schmidt, Keith Sklower, Ian Lance Taylor, and G. N. Ananda Vardhana. A special thanks to the consulhng editor, Brian Kernighan, for his rapid, thorough, and he1pfUl reviews throughout the course of the project, and for his continued encouragement and support.
Our thanks (again) to the National OPtical Astronomy Observatories (NOAO),especially Sidney Wolff, kichard Wolf f and Steve Grandi, for providing access to their networks and hosts. Our thanks also to the U.C. Berkeley CSRGf Keith Bostic and klrk McKusick provided access to the latest 4.4BSD system, and Keith Sklower provided the modifications to the 4.4BSD-Lite softWare to run under BSD/386 V1.1.,
G.R.W wishes to thank John Wait, for several years of gent1e prodding; Dave Schaller, for his encouragement; and Jim Hogue, for his support during the writing and production of this book.
W.R.S. thanks his family, once again, for enduring another "small" book project.Thank you Sally Bill, Ellen, and David.
The hardwork, professionalism, and support of the team at Addison-Wesley has made the authors' job that much easier. In particular, we wish to thank John Wait for his guidance and Kim Dawley for her creative ideas.
Camera-ready copy of the book was produced by the authors. It is only fitting that a book describing an industrial-strength softWare system be produced with an industrial-strength text processing system. Therefore one of the authors chose to use the Groff package written by James Clark, and the other author agreed begrudgingly
We welcome electronic mail from any readers with comments, suggestions, or bug fixes f tcpipiv2--book@aw. com. Each author will gladly blame the other for any remaining errors.
Gary R. Wright W Richard Stevens
http: //www. connix. com/~guright http: / /www. koha1a. com/ ~rstevens
Middletown, Connecticut Tucson, Arizona
November 1994
(美)Gary R.Wright,W.Richard Stevens：W.Richard Stevens: W. Richard Stevens (1951~1999) 是一位非常受人尊敬的专家，除了《TCP/IP详解》三卷本外，他还有其他两部最为畅销的作品：《UNIX环境高级编程》和《UNIX网络编程》(两卷本)。
Chapter 1. IntroductIon
1.1 Introduction 1
1.2 Source Code Present8tion 1
1.3 story 3
1.4 AppIication Programming Int6rfaces 5
1.5 Example Program 5
1.6 System CaIls and Library FunCtions 7
1.7 NetWork lmpIement8tion Overview 9
1.8 Descriptors 10
1.9 Mbufs (Memory Buffers) and Output Processing 15
1.10 lnput Processlng 19
1.11 NetWork lmpIementation Overview Revis1ted 22
1.12 Interrupt Levels and Concurrency 23
1.13 Source Code Organization 26
1.14 Test Netwoth 28
1.15 Summary 29
Chapter 2. Mbufs: Memory Buff6rs
2.1 IntroduCtion 31
2.2 Code lntroduction 36
2.3 Mbuf DefinitIons 37
2.4 mbuf Structure 38
2.5 Simple Mbuf Macros and Functions 40
2.6 m_devget and m_pul1up Functions 44
2.7 Summary of Mbuf Macros and FunCtions 51
2.8 Summary of NeU3 Nberking D8ta StruCtures 54
2.9 rucorw and CIust6r Reference Counts 56
2.10 Alternatives 60
2.11 Summary 60
ChaPter 3. lnterf8ce Layer
3.1 lntrOduCtion 63
3.2 Code Introduction 64
3.3 lf net StrUCtUre 65
3.4 ifaddr StruCture 73
3.5 sockaddr StruCture 74
3.6 lf net and ifaddr SP6ciaIiz8tion 76
3.7 NetWork InitiaIizatton Overview 77
3.8 Ethern6t lnitialization 80
3.9 SLlP lnitiaIiz8tion 82
3.10 Loopb8ck InitiaIiZaion 85
3.11 lf--attach FunCtion 85
3.12 1flnit FunCtton 93
3.13 Summary 94
ChaPter 4. lnt6deces: Ethernet
4.1 IntroduCtion 95
4.2 Code IntrOduCtion 96
4.3 Ethernet lnterf8ce 98
4.4 1octl SyStem CatI 114
4.5 Summary 125
Chapter 5. lnt6rfaces: SLlP and Loopback
5.1 lntrOduCtion 127
5.2 Code lntroduction 127
5.3 SUP lnterf8ce 128
5.4 Loopback lnterf8ce 150
5.5 Summary 153
Chapt6r 6. lP Addressing
6.1 IntroduCtion 155
6.2 Code Introduction 158
6.3 tnterface and Address Summary 158
6.4 sockaddr--ln StruCture 160
6.5 in--ifdddr StruCture 161
6.6 Address Assignment 161
6.7 Interface ioct1 Processing 177
6.8 lnternet Utility FunCtions 181
6.9 if net Utility FunCtions 182
6.10 Summary 183
ChaPter 7. Domains and Pndocols
7.1 IofroduCtion 185
7.2 Code IntrOduCtion 186
7.3 domain StruCture 187
7.4' protosw StrUCtUre 188
7.5 IP domain artd protosw Structures 191
7.6 pfflndproto and pffindtype FunCtions 196
7.7 pfct1input Function 198
7.8 IP lnitiaIization 199
7.9 sysctl System CaII 201
7.10 Summary 204
Chapt6r 8. lP: lnt6rn6t Protheol
8.1 IntroduCtion 205
8.2 COde IntroduCtion 206
8.3 IP P8Ck6ts 210
8.4 lnPut Processjng f ipintr Function 212
8.5 FOrWarding' iPforwaId FunCtion 220
8.6 Output PMssinQ' ip--output FunCtion 228
8.7 Int6rnet Ch60ksum' in--cksum Funotinn 234
8.8 setsockopt and getsockopt SyStem CaIls 239
8.9 iPsysct1 FunCtion 244
8.10 Summary 245
ChaPter 9. IP OPtlon Processlng
9.1 IntbouCtion 247
9.2 Code Introdudion 247
9.3 Option F0rmat 248
9.4 ip--dooptlons FunCtion 249
9.5 Record Route Option 252
9.6 Source and Record Route OPtions 254
9.7 Timestamp Option 261
9.8 lp--lnsertoptions Function 265
9.9 lp--Pcbopts FunCtion 269
9.10 Limitations 272
9.11 Summary 272
Chapt6r 10. IP Fragment8tion and ReassembIy
10.1 lntroduCtion 275
10.2 C0de lntrOductIon 277
10.3 Fmpmentation 278
10.4 lp--optcopy FunCtion 282
10.5 ReassembIy 283
10.6 ip--reass FunCtion 286
10.7 ip--s1owtlmo FunCtion 298
10.8 Summary 300
Chapter 11. ICMP: lnternet Control Message Pbocol
11.1 lntroduCtion 301
11.2 Code lntroduCtion 305
11.3 ictnp StruCture 308
11.4 lCMP protosw StruCture 309
11.5 Input Processing: icmP--input Fuodion 310
11.6 Error Processing 313
11.7 Request Processing 316
11.8 RedireCt Processing 321
11.9 RepIy Processing 323
11.10 Output Processing 324
11.11 icmP--error Fun0tion 324
11.12 lcro--ret1ect FunCtion 328
11.13 icmP--send Function 333
11.14 lcco--sysctl FunCtIon 334
11.15 Summary 335
Chapter 12. lP MuItlcastlng
12.1 lotrOduCtion 337
12.2 Code lntrOdodion 340
12.3 Ethern6t MuIticaSt Addresses 341
12.4 etheramulti StruCture 342
12.5 Ethern6t Multicast Reception 344
12.6 ininultl StrUCtUre 345
12.7 ippooptions StrUCtUre 347
12.8 MuIticast S0Cket OPtIons 348
12.9 MulticaSt TTL V8Iues 348
12.10 ip_setmoptions FunCtion 351
12.11 Joining an lP MuIticaSt Group 355
12.12 Leaving an tP MulticaSt Group 366
12.13 lp--getmoptlons Function 371
12.14 Multicast Input Processing: ipintr FunCtion 373
12.15 Multicast Output Processing f ip--output FunCtion 375
12.16 Perf0rmance Considerations 379
12.17 Summary 379
ChaPter 13. lGMP: lnternet Group Management ProtocoI
13.1 IntroduCtion 381
13.2 Code IntroduCtion 382
13.3 lgmp StrUCtUre 384
13.4 IGMP protQsw StrUCtUre 384
13.5 Joining a Group f lgmp--3olngroup FunCtion 386
13.6 lgmp--fasttimo Function 387
13.7 lnput Processingt igmp--lnput Function 391
13.8 Leaving a Group f lgmp--leavegroup Function 395
13.9 Summary 396
Chapt6r 14. IP MuIticast Routing
14.1 Introduction 397
14.2 Code Introduction 398
14.3 Mufticast Output Processing Revisit6d 399
14.4 mrouted Daemon 401
14.5 VirtuaI lnterfaces 404
14.6 IGMP Revisited 411
14.7 Multicast Routing 416
14.8 Multicast FOrwarding f lpamforward Function 424
14.9 Cleanup; ipinrouter--done Function 433
14.10 Summary 434
Chapt6r 15. Socket Layer
15.1 IntroduCtion 435
15.2 Code lntroduCtion 436
15.3 socket Structure 437
15.4 System Calls 441
15.5 Processes, Descriptors, and Sock6ts 445
15.6 socket System Call 447
15.7 getsock and sockargs FunCtions 451
15.8 blnd System CalI 453
15.9 llsten SyStem Call 455
15.10 ts1eep and wakeup FunCtions 456
15.11 accept System CaII 457
15.12 sonewconn and soisconnected Functions 461
15.13 connect System caII 464
15.14 shutdown System Call 468
15.15 close System Call 471
15.16 Summary 474
Chapter 16. Sock6t UO
16.1 Introduction 475
16.2 Code Introduction 475
16.3 Socket Buffers 476
16.4 wrlte, writev, sendto, and sendrisg System Calls
16.5 sendrisg System Call 483
16.6 sendlt FunCtion 485
16.7 sosend FunCtion 489
16.8 read, readv, recvfrom, and recwnsg Syst6m Calls
16.9 recwnsg System CalI 501
16.10 recvlt FunCtion 503
1 6.1 1 sorecelve FunCtIon 505
16.12 sorece1ve Code 510
16.13 se1ect System Call 524
16.14 Summary 534
ChaPter 17. Socket OPtions
17.1 lntrOduCtion 537
17.2 Code lntrOduCtion 538
17.3 setsockoPt System CalI 539
17.4 getsockopt SyStem CalI 545
17.5 fcntl aed 1oct1 System CaIls 548
17.6 getsockname SyStem CalI 554
17.7 getpeername Syst6m Call 554
17.8 Summary 557
ChaPter 18. Radix Tree Routing TSbIes
18.1 lntrOduCtion 559
18.2 Routing T8ble StruCture 560
18.3 RoUting SOCkats 569
18.4 COde lntrOduotion 570
18.5 Radix Node Data StruCtures 573
18.6 Routing StruCtures 578
18.7 Initia[izationt route--lnlt and rtable--lnlt FunCtions 581
18.8 lnitialhation' rn--init and rn--inlthead FunCtions' 584
18.9 Duplicate Keys and Mask LiSts 587
18.10 rnamatch FunCtion 591
18.11 rn--search FunCtion 599
18.12 Summary 599
Chapt6r 19. Routing Requests and Routing Messages
19.1 lntrOduCtion 601
19.2 rta11oc and rta11ocl FunCtions 601
19.3 RTFREE Macro and rtfree FunCtion 604
19.4 rtrequest FunCtion 607
19.5 rt--setgate Function 612
19.6 rtinit FunCtion 615
19.7 rtredirect FunCtion 617
19.8 Routing Message Structures 621
19.9 rtamissmsg FunCtion 625
19.10 rt--zfmsg FunCtion 627
19.11 rt--newaddrmsg Function 628
19.12 rt--msg1 FunCtion 630
19.13 rt--msgz FunCtion 632
19.14 sysct1--rtab1e FunCtion 635
19.15 sysctl--dumpentry FunCtion 640
19.16 sysct1--if1lst FunCtiOn 642
19.17 Summary 644
Chapter 20. Routing SOck6ts
20.1 IntroduCtion 645
20.2 routedomain and protosw StruCtures 646
20.3 Routing ControI BIocks 647
20.4 rawinit Fuodion 647
20.5 route--output FunCtion 648
20.6 rt--xaddrs FunCtion 660
20.7 rt--setmetrics FunCton 661
20.8. rawinput FunCtion 662
20.9 route--usIreq FunCtion 664
20.10 rawusrreq Funoton 666
20.11 rawattach, rawdetach, and ravidisconnect Fun
20.12 Summary 672
Chapter 21. ARP: Address ResoIutlon ProtOcoI
21.1 Introduction 675
21.2 ARP and the Routing Table 675
21.3 Code lntrOduction 678
21.4 ARP StruCtures 681
21.5 arpwhohas Function 683
21.6 arprequest FunCtion 684
21.7 arpintr FunCtion 687
21.8 in--arp1nput Function 688
21.9 ARP Timer FunCtions 694
21.10 arpreso1ve FunCtion 696
21.11 arplookup Function 701
21.12 Proxy ARP 703
21.13 arPrtrequest FunCtion 704
21.14 ARP and MuIticasting 710
21.15 Summary 711
Chapter 22. PtOtocoI Control 8Iocks
22.1 Intrduction 713
22.2 Code Introduction 715
22.3 inpcb StruCture 716
22.4 in--Pcbal1oc and inWcbdetach FunCtions 717
22.5 Binding, ConneCting, and DemuItiplexing 719
22.6 in--Pcb1ookup FunCtion 724
22.7 in--Pcbbind FunCtion 728
22.8 in--Pcbconnect FunCtion 735
22.9 lnwcbdiseonnect FunCtion 741
22.10 in--setsockaddI and ln--setpeeIaddr FunCtions'
22.11 inwcbnoti fy, iflrtchange, and in--iosinq FunedQ
22.12 ImpIement8tion RefinementS 750
22.13 Summary 751
Chapter 23. UDP: User Datagram Pl'Otocol
23.1 IntrOduotion 755
23.2 Code lntrOduCtion 755
23.3 UDP protosw StrUCtUre 758
23.4 UDP Header
23.5 udp--l nzt FunCtion
23.6 udp--output Function
23.7 udp--lnput FunCtion
23.8 udp--saveopc Function
23.9 udp--ct1znput FonCtion
23,10 udp--usrreq Function
23.11 udp--sysct1 Function
23.12 ImpIementation Refinements
23.13 Summary
Chapter 24. TCP: Transmlsslon ControI Protocol
24.1 lntroductlon
24.2 Code IntroduCtion
24.3 TCP protosw StruCture
24.4 TCP Header
24.5 TCP ControI Block
24.6 TCP State Transitlon Diagram
24.7 TCP Sequence Numbers
24.8 tcp--znit Function
24.9 Summary
Chapter 25. TCP Timers f
25.1 IntroduCtion
25.2 Code lntroduCtlon
25.3 top--cance1 t lmers Function
25.4 top--fastt 1 mo Function
25.5 top--s1owt lmo FunCtion
25.6 top--t l meI's Function
25.7 Retransmiss1on Timer CalcuIations
25.8 tcp--newt cpcb Function
25.9 top--set pe1fs i st Function
25.10 top--xml t--t imer Function
25.11 Retransmission Timeout' tcp(t imers Function
25.12 An Rri ExampIe
25.13 Summary
Chapter 26. TCP Output
26.1 Introduction
26.2 t cp--output Overview
26.3 Determine if a Segment ShouId be Sent
26.4 TCP Options
26.5 Window ScaIe Option
26.6 Timestamp Option
26.7 Send a Segment
26.8 top--templ at o FunCtion
26.9 top--respond Function
Chapter 27. TCP Functions
27.1 Introductlon
27.2 tcp--drain Function
27.3 tcp--drop Function
27.4 tcp--close Function
27.5 tcpamss Function
27.6 tcp--ct1input Function
27.7 tcp--notlfy Function
27.8 tcp--quench Functlon
27.9 TCP--REASs Macro and tcp--reass FunCtion
27.10 tcp--trace Function
27.11 Summary
Chapter 28. TCP Input
28.1 Introduction
28.2 Prelimfnary Processing
28.3 tcp--dooptlons Function
28.4 Header Prediction
28.5 TCP lnput: Slow Path Processing
28.6 InitiatIon of Passive Open, Completion of ACtive Open
28.7 PAWS f Protection Against Wrapped Sequence Numbers
28.8 Trim Segment so Data is Within Window
28.9 Self-Connects and SimuItaneous Opens
28.10 Record Tlmestamp
28.11 RST Processing
28.12 Summary
Chapter 29. TCP Input (Continued)
29.1 lntroduction
29.2 ACK Processing Overview
29.3 CompIetion of PassIve Opens and SimuItaneous Opens
29.4 Fast Retransmit and F8st Rec0very Algorithms
29.5 ACK ProcessIng
29.6 Update Window lnfOrmation
29.7 Urgent Mode Processing
29.8 tcpxulloutofband Function
29.9 Processing of Recelved Data
29.10 FIN Processing
29.11 Final Processing
29.12 lmpIementation Refinements
29.13 Header Compression
29.14 Summary
Chapter 30. TCP User Requests
30.1 Introduction
30.2 tcp--usrreq Function
30.3 tcn a ttAnh Flinntinn
30.5 top--usrc losed FunCtion
30.6 top--ct1output FLJnCtion
30.7 Summary
Chapter 31. BPF: BSD PScket Filt6r
31.1 IntrOduCtion
31.2 Code lntroduction
31.3 bpf--if Structure
31.4 bpf--d StrUewre
31.5 BPF Input
31.6 BPF Output
31.7 Summary
Chapter 32. Raw IP
32.1 IntrOduCtion
32.2 COde lntrOduCtion
32.3 Raw IP protosw StruCture
32.4 rlp--init FunCtion
32.5 rip--input FunCtion
32.6 riPoutput FunCtion
32.7 riPusrreq FunCtion
32.8 rlp--ct 1output FunCtiOn
32.9 Summary
Epilogue
Appendix A. SoIutlons tO selford Exercises
Appendix B. Source Code AvaIIabiIity
Appendix C. RFC 1122 CompIlance
C.1 LinkL8yer R6quirementS
C.2 IP Requirements
C.3 IP OPtions R6quirements
C.4 lP Fragmeofation and ReassembIy Requirements
C.5 lCMP Requirements
C.6 MuIticoding R6quirements
C.7 IGMP Requirements
C.8 Routing Requirements
C.9 ARP RequirementS
C.10 UDP Requirements
C.11 TCP Requirements
Bibliography
Index
