wangjian@sspu.edu.cn
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1-05 APPANET TCP/IP Internet ISP Internet ISP
1-06 (Internet Draft) RFC (Proposed Standard) RFC (Draft Standard) (Internet Standard)
1-07 internet Internet internet Internet TCP/IP
1-08 1WANInternet 2 34 PAN
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1-10 x bit k d sb(b/s) s(s)p(bit) k kd + x b + s kd + x p p b + (k 1) p b (k 1) p b kk-1 s > (k 1) p b x p
1-11 x (p+h)(bit),p h p k b(b/s) p 1-12 D = kd + (x/p) ((p + h)/b) + (k 1) (p + h)/b D p 0 p = (xh)/(k 1)
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1-13
1-14 RTT
1-15 90% UD D 0 U=90% D= D 0 1 U D D 0 =10 10
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1-17 1000km 2 10 8 m/s 110 7 bit, 100kb/s210 3 bit, 1Gb/s t s = 10 7 /10 5 = 100s t p = 10 6 /(2 10 8 ) = 0.005s t s = 10 3 /10 9 = 10 6 s t p = 10 6 /(2 10 8 ) = 0.005s
1-18 2 10 8 m/s. L 1 10cm2 100m 3 100km4 5000km 1Mb/s 10Gb/s =0.1/(2 10 8 )=5 10 10 1Mb/s: =5 10 10 1 10 6 = 5 10 4 1Gb/s: =5 10 10 1 10 9 = 5 10 1 =100/(2 10 8 )=5 10 7 1Mb/s: =5 10 7 1 10 6 = 5 10 1 1Gb/s: =5 10 7 1 10 9 = 5 10 2
1-18 2 10 8 m/s. L 1 10cm2 100m 3 100km4 5000km 1Mb/s 10Gb/s =100 10 3 /(2 10 8 ) = 5 10 4 1Mb/s: =5 10 4 1 10 6 = 5 10 2 1Gb/s: =5 10 4 1 10 9 = 5 10 5 =5000 10 3 /(2 10 8 ) = 2.5 10 2 1Mb/s: =2.5 10 2 1 10 6 = 2.5 10 4 1Gb/s: =2.5 10 2 1 10 9 = 2.5 10 7
1-19 100 20 TCP 20 IP 18 1000 100/(100+20+20+18)=63.3% 1000/(1000+20+20+18)=94.5%
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1-21 OSI
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1-23 3
1-24 OSI TCP/IP 0 frame
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1-25 Windows
1-26 - (entity) (client)(server)
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1-27 everything over IP IP over everything TCP/IP everything over IP IP IP over everything