.


:




:

































 

 

 

 





 

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, .

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- , .

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 , . .

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.

, , . , , .

:

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 ;

n Internet.

10. TELNET -

n , ;

n ;

n .

 

, , .

5.1. .

5.2. .

5.3. .

5.4. .

 


 

6

 

/ Ethernet

 

: , /; , .

:

- ;

- 3;

- ;

- 4.

- .

 

2.1. /

 

/ . / Ethernet , . Ethernet .

/ . . , , . , , , (). , , , , . ( - ), . , , .

. , , . , p - , , , , p. (1-p) t . 1- , . , .

, .

/, 1- Ethernet. , , . , . .

, /.

.

 

.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.

 

.4

 

; . , , - ( 4). / . 64- , , .

, , . (. 4).

.5.

 

, . , 1 , . 0 , . 5 , , .

 





:


: 2015-10-20; !; : 475 |


:

:

, .
==> ...

816 - | 656 -


© 2015-2024 lektsii.org - -

: 0.132 .