????? Computer Networks

1
?????Computer Networks

• http//if.ustc.edu.cn/course/

2
???

• Andrew S. Tanenbaum, Computer Networks (5th
  Edition), Prentice Hall, 2010
• ???????? (?4?),????,???????
• Larry L. Peterson, Bruce. S. Davie, Computer
  Networks A System Approach (5th Edition) ,
  Morgan Kaufmann, 2011
• ????????????(?3????4?),???????

3
?????????

• ????54????,20????
• ????
• ????70
• ????10
• ????20

4
????

• ???313??
• ??
• ??
• ???

5
?????????

• ????????????????????????,?????????,???????????????
  ?
• ????????,????????
• ??????????????

??? 1)??????????? 2)???????????
6
????????

• ??(link)????????????????
• ???(Point-to-Point)??
• ????(Multiple Acess)/????
• ??(node)?????????,????????????????

7
??????????

• ????,??????????????????????
• ???????????????
• ????,???
• ????????
• ??????????????
• ????????????????????
• ??????????

???
8
?????????(internet)

• ???????????????????(internet)
• ??????????????????????(Router)/??(Gateway)
• ??????????????,??????????????????
• ??????,????????????????(network)

9
??????Internet

• Internet(???)?????????
• ??Internet(???)??
• ????????( Advanced Research Projects Agency
  Network )
• ???Internet???
• ??????????Internet,??????????????,???????????????
• Internet???????????????
• Internet????????????????,?????????????????
• ???,????????TCP/IP??,??????Internet

10
????

• ?????????????
• ??????????
• ????????????????????,???????
• ???????????

11
????

1. ??
2. ???
3. ?????
4. ??????????
5. ???
6. Internet Protocol
7. ???
8. ???
9. ????

12
Chapter 1 ??

• 1.1 ??Internet ????
• 1.2 ??Internet????
• 1.3 IPv6???
• 1.4 Internet???
• 1.5 ??????
• 1.6 ?????
• 1.7 ??????

13
1.1??Internet ????
?????IEEE Infocom 2006 keynote speech, UCLA??,
Len Kleinrock?? "The Internet History,
Development and Forecast" http//www.comsoc.org/v
ideo/infocom/06/index.html

• Internet???(?????,???(internet))
• ??????????,?????????????????,???????(ARPAnet)????,
  ????TCP/IP???
• ??
• 1969?????????????????ARPAnet
• 1974?,??TCP/IP?????,1980??,??????(DNSDomain Name
  System)
• 1985?,?????????NSF??TCP/IP???,??NSFNet
• 90???,Internet????,???????????
• 93???????????????(????????,NII,National
  Information Infrastructure),??????????????????????
  ???????, GII(Global Information
  Infrastructure)?????
• 1997?7?,?????NGI(Next Generation Internet)
• 2005???NSF??GENI(Global Environment for
  Networking Innovation)?FIND (Future INternet
  Design)

14
14
15
15
16
16
17
What was the first message even sent on the
Internet?

• 1844?,?????Morse??????What hath God Wrought
• 1876?,?????Bell?????? Watson, come here. I
  want you.
• 1969?,Armstrong?????????One Giant Leap for
  Mankind.

It was simply a LOGIN from the UCLA computer to
the SRI computer.
Nobody noticed!!
17
18
1969?12??ARPAnet
?? ?? OS
UCLA(?????????) SDS Sigma 7 SEX
SRI(??????) XDS-940 Genie
UCSB(??????????) IBM 360/75 OS/MVT
UTAH(??????) Digital PDP-10 TENEX
18
19
1988??NSFNet
19
??
20
??

• This large graph shows the router level
  connectivity of the Internet as measured by Hal
  Burch and Bill Cheswick's Internet Mapping
  Project

20
21
Chapter 1 ??

• 1.1 ??Internet ????
• 1.2 ??Internet????
• 1.3 IPv6???
• 1.4 Internet???
• 1.5 ??????
• 1.6 ?????
• 1.7 ??????

22
1.2??Internet????
?????

• 1989?9?,???????????????????????????(NCFC,The
  National Computing and Networking Facility of
  China),1992?NCFC???????(????????CSTNet)
• 1994?5?,NCFC????????Internet,?InterNIC??CN???
• 1994?9?,??????????(Chinanet)??????,96?1??????
• 1994?10?,???????(Cernet)?????
• 1996?9?,?????(ChinaGBN)?????
• 1997?,Chinanet?CSTNet?Cernet?ChinaGBN?????

23
1.2??Internet????(?)
24
????
???2011?12?,??????????3.56?
25
(No Transcript)
26
Cernet?????
?????
27
CERNET??????
28
(No Transcript)
29
(No Transcript)
30
Chapter 1 ??

• 1.1 ??Internet ????
• 1.2 ??Internet????
• 1.3 IPv6???
• 1.4 Internet???
• 1.5 ??????
• 1.6 ?????
• 1.7 ??????

31
IPv4????
Fromhttp//ipv6.he.net/statistics/ Date
2011.04.26
32
1.3 IPv6???

• IPv6 is sometimes also called the Next Generation
  Internet Protocol or IPng.
• ??
• IPv6 was recommended by the IPng Area Directors
  of the Internet Engineering Task Force at the
  Toronto IETF meeting on July 25, 1994 in RFC 1752
• The core set of IPv6 protocols were made an IETF
  Draft Standard on August 10, 1998.
  ,RFC2460,Internet Protocol, Version 6
  (IPv6),DEC,1998 Specification
• 1996?3???IPv6???(6bone)??
• ??
• 1998?4?,CERNET???????IP??(IPv6)???6BONE?8???
  863????IPv6????
• 2002?1?,????????????IPv6?????
• 2003?8?,????????????????"?????????????????????",??
  ??"????????????CNGI"???????2003??2005?????,??IPv6?
  ?,??CNGI???(??20???30?????)
• ???? ,????????????????????
• ????????????,?????????????????????7?????????
• ????,????????????
• ????,???????IPv6???
• CERNET2???????,???2.5G???????????????????

33
CERNET2 ???
34
??????????????,????NGI NGN
?????
???
1835????
1876??????3.4KHz
1960??????64Kb/s
1988?ISDN 192Kb/s-2Mb/s
1992?B-ISDN 155Mb/s-622Mb/s
2000? ???? Gb/s-Tb/s ???
?????
1976??????9.6Kb/s-64Kb/s
1990?????245Mb/s
NGN
21??? B3G/4G LTE/LTE
2000? W-CDMA(3GPP) CDMA2000(3GPP2)
???
80??????
90??GSM
IP
750MHz1GHz 200ch???TV cable modem
?????
450MHz 60ch.??TV
70??CATV
1994?HFC
NGI
21????WPAN/WLAN/WMAN 802.16(WiMAX)
1997 802.11(WiFi)
70?? 10BASE-5 10Mb/s
80?? FDDI 100Mb/s
90??? 100BASE-T 100Mb/s
97? GBE 1000Mb/s
??????
90??? ATM-LAN
1969? ARPA
1982? TCP/IP
1992? IPv6,RTP RSVP
1998? IP OVER SDH IP OVER WDM
1996? ?3,4???
???
35
Chapter 1 ??

• 1.1 ??Internet ????
• 1.2 ??Internet????
• 1.3 IPv6???
• 1.4 Internet???
• 1.5 ??????
• 1.6 ?????
• 1.7 ??????

36
1.4Internet???
???? Electronic mail FTP Telnet WWW
?????
Video conferencing
???? Intelligent Transportation Systems
Remote control
Internet (Global infrastructure for information
which uses TCP/IP Communication)
???? Information Appliance
Distributed databases
Electronic commerce
IP Phone Video Phone
Remote Education
Telemedicine
Digital video/ audio/applications download
Interconnection of networks (Intranets,VPN)
37
?????
???/???
????????gt????,????? ???????? C/S gt p2p
38
???P2P

• ???
• ????
• ??,??
• ????

• ????
• ????
• ??,???
• ????

39
Chapter 1 ??

• 1.1 ??Internet ????
• 1.2 ??Internet????
• 1.3 IPv6???
• 1.4 Internet???
• 1.5 ??????
• 1.6 ?????
• 1.7 ??????

40
???????????

• ??????????????????????????????????????????
• ????????????????,??????????

41
??????

• ???????????????????
• ??(Switching)??????????????????,?????????,???????
  ????????????
• ??(Addressing)??????????????????/??
• ????(Routing)??????????????????,?????,???????????
  ????????
• ??(Protocol)???????????????????????????,?????????
  ??

42
??

• ????????,?????????(Circuit Switching),????????????
  ???????????,?????????????????????
• ???????,?????????(Packet Switching),????????,?????
  ?????
• ??(Packet) ????????,??????????????
• ????????????????

????
????
43
??(?)

• ??????,???????????(Store-and-Forward),????????????
  ???,????????,???????????????????????
• ????????????

44
??(?)

• ???????????????
• ???????????????????????????

• ????(Multiplexing)
• ??????
• TDMTime-Division Multiplexing
• ??????
• FDMFrequency-Division Multiplexing)

Frame
???????????????(Statistical Multiplexing)
45
??(?)

• ??????
• ?TDM??,????????????????,?????????????????(time
  slot)
• ?????????????????,?????????????,?????????,????????
  ?
• ???????????????????????????(Fairness)
• ?????,?????????????,??????????????????????
• ????????????????????

46
??

• ?????????(Address)??????,?????????????
• ????(Unicast Address)???????????????
• ????(Broadcast Address)???????????????
• ??/????(Multicast Address)????????????,??????????
  ????

47
????

• ?????????????????????????,???,????????????,???????
  ????,????????????????????
• ??,?????????????????????????,?????????????
• ??????????????,??????,???????????????,????????????
  ????

48
??

• ??????,?????,?????????????????????????????????????
  
• ???????
• ????????????????????????
• ?????????
• ??????,???????????????????,????

49
????????????????????????????????????????,?????,???
???????????????????????????????????????????
??????,????????????????????????,????????????
???????????????????
50
?????
???????

• ????????,??????????????????
• ??????,??????????
• ??????????????
• ????????????????,????????????????
• ?????,??????????????????????????

??3
??6
??1
??5
??4
??2
???????????????,?????????????
51
?????

• ?????
• ???????????????????????,??????????
• ???????????????,????????,??????????,??????????????

????
????
52
?????
?n1?
?n1?
?n??????
n/n1???
?n?
?n?
?n???
???(Peer Entity)
?n-1?
?n-1?

• ????????????????,???????????,?????????,?????????
• ????????????????????????????????????????
• ????????,???????????????????????,?????????????????
  ???
• ?????????????????,???????,????????

53
????
??????
??????????
????????
????
??????
????

• ??????????(Primitive)???,?????????????????
• ????????????????,??????????,??????????????????????
  ???

54
?????????
n1?
n?
n1?
request
indication
response
confirm
??A
??B
55

• ????????
• 1 COENNCT.request dial
• 2 CONNECT.indication ring
• 3 CONNECT.response pick up
• 4 CONNECT.confirm ringing stops
• 5 DATA.request say something
• 6 DATA.indication hears voice
• 7 DISCONNECT.request caller hangs up
• 8 DISCONNECT.indication busy tone

?n1?
?n?
?n1?
?n?
56
????
Layer n Protocol
Layer n Protocol
PDU
Layer n-1 Protocol
Layer n-1 Protocol
PDU

• ????????,????????????????(PDUProtocol Data
  Unit)?????????????????,???????
• ?????????,???????????????????PDU???,?????????????
  ??,???????

57
???????

• ???(Protocol Stack)??????????????
• ???(Protocol Grpah)???????????????????
• ??????,???????
• ????????????????????????????
• ????????
• OSI????
• Internet????

???
58
OSI????

• OSI?????ISO?1983???,??OSI????
• ISOInternational Standards Organization,???????
• OSIOpen Systems Interconnection,??????
• ???,OIS?????????????(?)????,???????????,

?????
??????
?????
?????
?????
??????
59
???

• ????
• ???????????????ISDN???????????????????,???????????
  ??????
• ????????,?????????????,???????????
• ????????
• ????
• ??????????,??????????????????????????
• ?????????(Amplifier)????(Hub)

60
?????

• ????
• ???????,????????????,??????,?????????????,????????
  ??,????????????
• ????????????????????????????
• ????????????????????????????????,????????????????
  ??,?????????MAC (Media Access Control)
• ??????????????????????
• ????
• ??????????HLDCP(High Level Data Control
  Procedure)
• ?????PPP(Point to Point Protocol)
• ??????(Bridge)?(L2)???(Switch)

???????????????
61
???

• ?????????,????????????,?????????????
• ????????????????
• ????
• ATM???????????????????????????(??????????),??????
  ??????,??????????,?????????
• IP?????????????,????????,????,???????????,???????
  ?????
• ????????(L3)???

62
???

• ????
• ??????????????,???????????
• ???(end-to-end),???????????,??????????
• ??????????
• ????????????????????????????????(??????????????)
• ???????????,??????

???????????????????????
??????????????????????????(Gateway)
63
???????????

• ???????
• ????????????????
• ??????????,??????,????????????,????,??????????????
  ?,??????
• ???????
• ??????,??????????????,????????????????????
• ??????????????
• ???????
• ??????????????

64
Internet????

• ??TCP/IP????
• TCP/IP??Internet????????IP(Internet
  Protocol)?TCP(Transmission Control Protocol)

65
TCP/IP???

• Applications
• Web
• Email
• Video/Audio
• TCP/IP
• Access Technologies
• Ethernet (LAN)
• Wireless (Wimax, WLAN, Cellular)
• Cable
• ADSL
• Satellite

Applications
???????? (????????overlay)
Middleware Services
Narrow Waist
??????????????, ?????????
TCP/IP
Network Technology Substrate
?????????????
Access Technologies
65
66
??????

• ??????????????,????????????TCP/IP?????????????????
  ,???????????
• ?Internet???????????????,?????OSI??????????
• ??????????????????????????

67
????

• ??????OSI????????
• ???IP??,?????IP???????????????????,???????????????

IP????????????Internet?????,?????????????????,????
???????
68
???

• ??????OSI????????
• ???????
• ??????TCP(Transmission Control Protocol)?????????
  ?????
• ???????UDP(User Datagram Protocol )?????????????

????????????????,?????????????????????TCP,???????
??????????????,????????,???UDP
69
???

• ??????????,??ISO???????????
• ????DNS????IP??
• HTTP??WWW??
• FTP????????
• Telnet????????
• SMTP????????

?????????? ??????????????????,????????????
70
??????????????????
???
???
???
?????
???
71
?????????
???????(???)
??A
???????(??)
???
L2 ???
L2 ???
???????(??)
??B
?????
72
Chapter 1 ??

• 1.1 ??Internet ????
• 1.2 ??Internet????
• 1.3 IPv6???
• 1.4 Internet???
• 1.5 ??????
• 1.6 ?????
• 1.7 ??????

73
?????

• ???????????????????,??????????,???????????????????
  
• ????
• ???????????,????????????????IBM
  PC????????????,???????????IBM???
• ???????????????????????????

74
??????ITU

• ITU International Telecommunication Union
• http//www.itu.int
• ITU????????
• ITU-R??????,?????????
• ITU-T???????,???????????
• V???????????,V.90 56kbps modem
• X?????????,X.25????
• G???????????????,G.726 ADPCM????
• H???????????,H.264(MPEG4 Part 10)????
• Q?????,Q.931
• ITU-D??????,????,????????????????????????

ITU-T?????????????????????????
75
???????ISO

• ISO International Standards Organization
• http//www.iso.org
• ISO???????????
• ISO?IEC?????????ISO/IEC JTC1,???????????
• ISO?ITU-T?????????????(ISO?ITU-T?????),??ISO/IEC?M
  PEG?ITU-T?VCEG???????JVT(Joint Video
  Team)???????????,??ISO/IEC?MPEG-4 Part
  10,??ITU-T?H.264

IECInternational Electrotechnical
Commission,??????????
ISO????????????,???ISO?????????????ANSI (American
National Institute),ANSI????ISO???????
76
??????????IEEE

• IEEEInstitute of Electrical and Electronics
  Engineers
• http//www.ieee.org
• IEEE?????????????????????
• IEEE 802??????IEEE 802????,???????????????????????
  ???MAC(Media Access Control)????
• IEEE 802.3???
• IEEE 802.15?????
• 802.15.1??,802.15.3a ???
• IEEE 802.11a/b/g/n?????
• IEEE 802.16 a/d/e ?????

IEEE????????????,????????????????
77
Internt??

• Internet??(Internet Society)???????Internet????,??
  ?????????????????????
• Internet?????????
• Internet???????IAB(Internet Architecture
  Board)??????Internet????,?IETF?????????
• Internet?????IETF(Internet Engineering Task
  Force)Internet??????????
• Internet?????IESG(Internet Engineering Steering
  Group)??IETF????????Internet?????

?ITU?ISO?IEEE????????,Internet?????????,???????www
.ietf.org??
78
Chapter 1 ??

• 1.1 ??Internet ????
• 1.2 ??Internet????
• 1.3 IPv6???
• 1.4 Internet???
• 1.5 ??????
• 1.6 ?????
• 1.7 ??????

79
???????

• ????(Bandwidth)
• ?????????????????,?????bps(bit/s)(Kbps?Mbps?Gpbs?)
  
• ????(Latency/Delay)
• ????(Propagation),????????
• Propagation Distance / Speed
• ????(Transmit),?????????????
• Transmit Size / Bandwidth
• ???? (Queue),????????????????????????
• ??????(Delay Jitter)

80
?????

• ?????(Throughput)
• ???????,?????????????
• ??802.11b????11Mbps,???????????,????????????4Mbps?
  ?
• ?????,????????????????

??????????????????????????,???????????,???????????
???????????
81
????

• 3,10,17,19,20,25