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1internetInternet1nternetInternetTCP/IP231WANInternet234PAN4RTT51.2.3.4.5.:13:123171000km2108m/s1107bit,100kb/s2103bit,1Gb/s1:ts=107/105=100s:tp=106/(2108)=0.005s2:ts=103/109=1s:tp=106/(2108)=0.005s1-20627CC=Blog2(1+S/N)bit/s)BSNdB=10lgS/N)81.2.97ADSL11231OSIOSI24(code)720000/16b/s?C=R*Log216=20000b/s*4=80000b/s83KHz64kb/sC=Wlog21+S/N(b/s)W=3khzC=64khz----S/N=64.2dB2-132-15CDMA10311CRC2P7012MACV2MACP8913P953-01()()??3-03??TCP/IPOSI3-06PPPPPPPPPPPP123A0xFF4C0x03PPP5PPPHDLCPPP6PPPPPP3-08101110CRCDPX=X3+1101110000100110113-281011010Mb/s210100Mb/s31010Mb/s:11010Mb/s10mbs210100mb/s100mbs31010mb/s10mbs14IP412315IPDR516P1331718NAT:1?:.VirtualCircuit3(relay)(repeater)(bridge)(router)(brouter)(gateway)4IPARPRARPICMPIPARPIPRARPIPICMPIP91255.255.255.0AAIP824255.255.255.08168BBIP1616255.255.255.01688CC2255.255.255.248255.255.255.24811111111.11111111.11111111.11111000.(2^3)=62981063ABsubnet-id16181A11111111111111111111111100000000161255.255.255.0B1111111111111111111111110000000081255.255.255.04B255.255.240.024010=128+64+32+1610=111100002Host-id4+8=122^12-2=4096-2=409411111111.11111111.11110000.000000002^12-2(5)A255.255.0.25510111111111111110000000011111111(6)IPC2.2F.14.81IPC22F1481--(12*16+2).(2*16+15).(16+4).(8*16+1)---194.47.20.129C22F1481---11000010.00101111.00010100.10000001C(7)C.CIP32,24,8.,8,,,20.128.96.39.0255.255.255.128m0128.96.39.128255.255.255.128m1128.96.40.0255.255.255.128R2192.4.153.0255.255.255.192R3*R451128.96.39.102128.96.40.123128.96.40.1514192.153.175192.4.153.901IP128.96.39.10255.255.255.128128.96.39.002IP128.96.40.12255.255.255.128128.96.40.0128.96.39.0255.255.255.128128.96.40.0R23IP128.96.40.151255.255.255.128128.96.40.128255.255.255.192128.96.40.128R44IP192.4.153.17255.255.255.128192.4.153.0255.255.255.192192.4.153.0R35IP192.4.153.90255.255.255.128192.4.153.0255.255.255.192192.4.153.64R438.IGPEGPIGPEGPEGPIGPEGPASASIGPAS39.RIPOSPFBGPRIPOSPFBGPUDPIPTCP1619UDP51.UDP2.UDP3.UDP4.UDP5.UDP6.UDP20UDP2122TCP23TCP()24p221,5-27.25TCP26TCPIP508UDPTCPUDPIPUDPUDPIPUDPTCP/514UDP06320045001CE217.UDP158669UDP2820UDP1023TFFTP527TCPTCPTCP65495TCP20IP20IP65535.IPIP20TCP65495TCPTCP5463BAAABAAABABAA27SNMP6SNMP1.SNMP2.SMI3.MIB2:IPDNSDNSIPISPIP56-05FTPFTP1FTPFTPFTP1212346-08::URLUniformResourceLocatorURL.?HTTP:HTTP.HTTPTCP?CGI:CGICGICGI?,hypertext?hypertextanchora?1.2.3.?MicrosoftWordWindowsHTML?6-24POPPOPSMTPIMAPPOPPOPPCPOPISPPOPPOPPOPPCIMAPISP6-461TCPFTPHTTPUDPDHCPSNMP2MIMESMTPSMIPSMTP3RIPUDPRIPUDPP36,1-01,1-03,1-17,1-20P63,2-01,2-04,2-07,2-08,2-13,2-15P109,3-01,3-03,3-06,3-08,3-28P183,4-01,4-03,4-04,4-09,4-20,4-28,4-38,4-39,4-45P231,5-08,5-13,5-14,5-24,5-27,5-31,5-39,5-46P2966-02,6-05,6-08,6-24,6-46