1. .
2. .
3. .
4. .
5
Internet
- Internet.
:
- ;
- 3;
- ;
- 4.
- .
internet Internet. internet , TCP/IP, Internet , internet . Internet , , , .
/ . . , , .
Internet. . Internet . , Internet , on-line , , , Internet.
. , . , . ( ). sendmail. Sendmail , . Unix- sendmail . . , , . , , Relcom UUPC, .
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Internet Simple Mail Transfer Protocol (SMTP), TCP. Unix-Unix-CoPy (UUCP) . UUCP . Relcom . SMTP UUCP , sendmail - on-line , . SMTP , .
Internet , . , :
n ;
n Usenet;
n FTP;
n WWW;
n Gopher;
n WAIS;
n LISTSERV;
n .500;
n WHOIS;
n Mailbase TRICKLE
Internet on-line. SMPT.
, , Internet . , -, , .
:
Usenet Internet. , Usenet, , . Internet, , (FAQ) . Usenet , , . Usenet .
FTP , 10-15 . . FTP , . FTP- Internet RFC, -, , , . . ( mirrors). , , , - , , . Archie, FTP- , .
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World Wide Web Internet. , WWW . World Wide Web Internet. , . . Internet. WWW . WWW , , , . Internet.
Gopher Internet. . Gopher , . Gopher , , .. Gopher . Gopher , , . Gopher 1994 WWW 1,5 , 1995 Gopher . Gopher- , World Wide Web.
WAIS - Internet. WAIS , freeWAIS. , . WAIS , . WAIS Internet, WWW Gopher. , WAIS, .
LISTSERV , , Internet, BITNET. , , Internet . LISTSERV . . LISTSERV, , , - EGS-4 . LISTSERV Usenet, , .
.500 . .500 , , , ..500 , . .
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WHOIS , .500, Internet. WHOIS .500 . WHOIS , WHOIS Internet, .
Mailbase , LISTSERV.
TRICKLE RTF, . , , TRICKLE.
, , .
, . , . . . hosts. Unix, /etc :
127.0.0.1 | localhost | localhost |
144.206.160.32 | Polyn | Polyn |
144.206.160.40 | Apollo | www |
. IP- , (alias). , , telnet Apollo:
telnet 144.206.160.40
telnet Apollo
telnet www
, Internet . . , DNS (Domain Name System).
DNS , TCP/IP. , IP-, .
. . . 80- : gov, mil, edu, com, net. , , uk, jp, au, ch .. . 1991 , , . , , Internet. , . , , su ( kiae.su) ru.
, , . , , .
:
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su
kiae msk
net dtk polyn
polyn cpuv1 apollo quest demin
DNS named, Berkeley Internet Name Domain (BIND).
Telnet Internet. , , RFC (Request For Comments).
telnet , :
n telnet- ;
n telnet-;
n telnet-.
.
Kermit BBS (Belluten Board System), , telnet .
Telnet RFC-854 (, 1983 ). J.Postel J.Reynolds telnet :
TELNET - , , , , - . - () - ( ).
Telnet TCP. telnet :
n (Network Virtual Terminal) NTV;
n ( );
n - .
telnet- , , , (Network Virtual Terminal). NVT. NVT . NTV .
WWW (World Wide Web)
1989 , .- , . , , . 1945 Memex. , , . 1965 . , , .
1. Internet.
n ;
n ;
n .
2. Sendmail.
n ;
n ;
n , .
3. Internet
n on-line;
n wais;
n x.500.
4. Usenet.
n Internet;
n Internet;
n Internet.
5. FTP:
n ;
n Internet;
n .
6. World Wide Web :
n ;
n ;
n .
7. World Wide Web:
n ;
n ;
n .
8. Gopher :
Internet;
- Internet;
.
9. WAIS :
n - Internet;
n ;
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n Internet.
10. TELNET -
n , ;
n ;
n .
, , .
5.1. .
5.2. .
5.3. .
5.4. .
6
/ Ethernet
: , /; , .
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2.1. /
/ . / Ethernet , . Ethernet .
/ . . , , . , , , (). , , , , . ( - ), . , , .
. , , . , p - , , , , p. (1-p) t . 1- , . , .
, .
/, 1- Ethernet. , , . , . .
, /.
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.1. /
. ( ). , . . tv. (. . 2). m, , t, , , 2t , , .
, . 2t , . 3: . , , . , . , t c.
.2. /
2t , .
, , 2tJ . J , .
E=G/S-1, . :
tv = m + t + 2tJ = m [1+a(1+2J)], aºt/m (1)
J. .
.3.
, (.2.) 2t u. , (2t) u, u*(1-u) .. , u , (1-u) - . J=1/u,
(2)
J u.
u .
n (n >> 1). , 2t c, p. , ,
u = n p ( 1 -p)n-1 . (3)
p=1/n , , n >> 1, ,
umax = ( 1 -1/n)n-1 e -1, n ¥ (4)
, u, (2), e -1. (1) :
tv = m [ 1 +a(1+2e)], aºt/m (1a)
, e-1.
lmax 1/ tu. l , , 1/ m ( ), (1.)
ºt/m
=0.1. , 10 .
r <0.6
, 0.18 0.368 . ( / m), rmax, 1.
20-
- t/2. / t=177 . . / m >> t. , £ 0.1. m = 1.77 c. 128- £ (128/1.77) = 72 /. , 256 / . , . , 40 , t=0.36 c ( 4.5 /). £ 0.1 m ³ 3.6 £ (128/3.6) * 1000 = 36 /. 20- .
/ 20- ?
r = 0.6 m = 1.77 ( 128- ) C = 72 /), , 0.6/m = 340 /. 1 15 , 5100 . , .
1 30 , 10000.
- , - . . 4.
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; . , , - ( 4). / . 64- , , .
, , . (. 4).
.5.
, . , 1 , . 0 , . 5 , , .