- , , .
: .
(.):
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2 :
(message switching) : . .
:
▪
▪
:
▪
, , ( )
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▪
▪
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▪ 璺 ( ). 璺.
:
,
( , , ). . , , , , .
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(cell), 㳿 , 53 . (ATM (Asynchronous Transfer Mode) - (53 ), ' , 48 - . ATM - , ).
8. C TCP/IP.
Transmission Control Protocol/Internet Protocol (TCP/IP) - , . Internet.
TCP/IP . . Request for Comment (RFC, Internet ( , , ).
̳ (Department of Defence, Do) 20 ' ARPAnet - . ARPA , ' ' Internet Protocol (IP), TCP/IP .
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TCP/IP , UNIX. UNIX IP . Internet, Internet Engineering Task Force (IETF) , RFC.
TCP/IP :
.
TCP/IP.
Internet.
intranet- , Internet WWW, Internet.
TCP/IP.
' , .
볺-.
TCP/IP.
TCP/IP 䳿 ISO/OSI, , , TCP/IP OSI .
TCP/IP 4 . TCP/IP:
( IV) OSI. TCP/IP , : Ethernet, Token Ring, FDDI, Fast Ethernet, 100VG-AnyLAN, - ' "-" SLIP PPP, X.25, frame relay. , 㳿 ATM (Asynchronous Transfer Mode- ) . 㳿 TCP/IP RFC, IP .
( III) - 䳿, , , ' ..
( OSI) IP, , , ' , '. IP 㳺, '. IP , , .
Internet Protocol (IP) - , '. ³ (TCP, UDP). IP internet, IP-, , TCP/IP. IP , . ; , '-. IP , . ³ () .
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䳿 , ' , RIP (Routing Internet Protocol) OSPF (Open Shortest Path First), ICMP (Internet Control Message Protocol). - . -ICMP , , , , .. RARP (Reverse Address Resolution Protocol)- MAC- IP-, ARP (Address Resolution Protocol).
( II) . TCP (Transmission Control Protocol) UDP (User Datagram Protocol).
TCP (Transmission Control Protocol) . ³ 볺 ' , '. , , ( ), .. , , , .
UDP (User Datagram Protocol) , , IP, ', , IP, - -. ³ , (datagrams), , . , UDP. UDP TCP, ' , ' ', UDP . 볺 , ' TCP , - , UDP. , TCP: Telnet, FTP SMTP. UDP ., , SNMP.
RTP ( ).
( I) . TCP/IP . , FTP, telnet, SMTP, . Internet, , WWW . .
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FTP (File Transfer Protocol) . , , FTP ' - TCP. FTP . , (, ). , FTP . , , ' . FTP- Internet , . - Anonymous.
TCP/IP FTP , . , FTP, , - TFTP (Trivial File Transfer Protocol). , , TCP, ' - UDP.
telnet , . '. telnet ', . telnet , , , Kerberos.
SNMP (Simple Network Management Protocol) . SNMP Internet, . SNMP - - , , .. SNMP .
' . 䳿 SNMP- ( ), SNMP- (' - ). , .
' , . , , . SNMP . , MIB (Management Information Base), , , .
9. MNP.
Գ Microcom Networking Protocol , , , MNP.
9 MNP ( ):
MNP.1 - ( , ) .
MNP.2 - - .
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MNP.3 - ' , SDLC, . - . , - 8 . CRC ARQ ( N-), , .
:
MNP.4 MNP.3, ; . ( ), .
MNP.5 . MNP.5 2:1. (V.42bis, CCITT 1990 , 3:1 - 4:1 ( )). MNP.5 ' , (, - ). , "" ( V.42bis ).
MNP.6 , , .
MNP.7 , MNP.5, V.42 bis.
MNP.8 .
MNP.9 , .
MNP.10 ( ); ( ). .
10. TCP UDP.
, , . / . = + +.
Transmission Control Protocol - TCP , , . 璺 . . . , TCP, FTP ( ) TELNET. , TCP X-Window, rcp (remote copy ) . TCP .
, UDP, ( , ). - . 璺, - .
². , , . , , , ( ). - ( . ) ( - , -= ). - - ( . ) . -, : . . >2 = time-out.
TCP IP, TCP , I-. I- (-) TCP . IP - TCP, . IP- , , TCP . .
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- . , Internet, (), -, .. . , , - out of band. , . 璺 . , - .
-, , , .
TCP :
, - .
Sequence Number- .
Acknowledgment Number- .. ACK, , . . - , ' .
Control Bits ( ) 6
URG: ACK:
PSH: RST:. '
SYN: FIN: /
Urgent Pointer - ( ), . URG.
Padding TCP , . 32- (. 0).
:
. TCP 볺 , Internet. TCP , .
. TCP , , . , (ACK) TCP, . , . , , . , .
. TCP , . "" (window) , , . ³ , .
. ' TCP, - . - Internet . (socket 璺). ' . , - '.
璺. , TCP . (. , , . '). 璺 (. ).
. 璺 .
User Datagram Protocol - UDP , , . UDP , Internet (IP). UDP , . UDP , , . UDP 2 : , UDP , UDP- . UDP-- UDP- user-datagram, . .
볺:
, . , . , -0.
- .
- , (. =8).
(. )- 16 UDP , . . IP. - , 0.
, , , UDP-, , , UDP . , TCP.
, , . 1. , . 0, , ( , , ).
:
-
- ,
- , , , .
UDP - I- , . :
UDP Internet Name Server, Trivial File Transfer.
Internet UDP 17 (21 ).
11. ' .
( ) ( ). . , RadioEthernet- , , , . - ' ( - ). DVB (Digital Video Broadcasting). DVB DTH (Direct To Home), - . , , , . 45 /.
璺 . ' ' . . ³ : , , ' ; - ( ). - . , , , , , - .
, , :
(Twisted Pair);
(Coacsial Cable);
(Filter Optic Cable).
-Twisted Pair. - 2 , , (1 ). (UTP/STP, unshielded/shielded twisted pair) . UTP/STP Ethernet, Token Ring ARCnet. ( ). . - ( 1 2 = /). - 8-12 /, , . .
Twisted Pair :
UTP (unshielded twisted pair)
STP (shielded twisted pair)
.
UTP.
Category 1 Category 2 ( v=4/)
Category 3 (v=10/c) Category 4 (v=16/c)
Category 5 (v=100/c) Category 5
Category 6,7
STP.
Type 1, Type 2 .
FTP .
S/FTP .
S/STP shielded/shared twisted pair +
-Coacsial Cable. . ³ Ethernet - ARCnet. .
. - core ( ), , (). . . , . . . .
:
Baseband .
Broadband .
( Baseband 50 O, Broadband 75 O).
4-5 /.
Baseband.
Thick ( 1 )
Thin ( 0.5 )
:
10Base5 10 10 /, Base- , 5 2- LAN. (10Base5 , 10Base2 ).
-Filter Optic Cable. , . ATM FDDI.
, , . , . - .
Single Mode Fieber- , 5-10 . , , , . ³ . 10 /. . . - .
Multi Mode Fieber- 50/125 62,5/125 . ' . , 2,5 /. 2 :
Step-index ( );
Grade-index ( 䳺, , );
' 璺. 璺 SC ST.
' , , , . '. , ', , , .
:
core (/), dc 50 ; (/), d 125 ; ; Գ ; ; .
:
:
Multi Mode Step-index 20-30 /
Multi Mode Grade-index /
Single Mode /.
:
, , , . .
:
. - Non Return to Zero -2 . ( ).
: ( )
AWG- , 22 AWG .
1. (STP) 2 22 AWG, .
2. , . 2- 22 AWG , 4- 26 AWG .
3. , 4- 22 24 AWG .
4. 2 dc/do 62.5/125
5. 2 26 AWG .
6. 2 26 AWG 璺 .
7. 2 ; .
12. . '.
.
(AM). (ASK - Amplitude Shift Keying) . , . AM '. AM ().
(). (FSK - Frequency Shift Keying) . , , -.
(). (PSK -Phase Shift Keying) . . () ().
.
:
o -, ();
o ();
o - (CAP);
o ( ), .
- (). ( - Pulse Code Modulation) ITU G.711. 8 256 (28), 8- . 64 / (8 8 ). - (IJ).
- (). - () . - ( ) 30-40 /. - . ³ () .
- ". , , . - .
.
: , , . : , , , . :
-, / | |||
< 2.4 | V.21 | ||
V.22 | |||
- 2.4...9.6 | V.22bis | ||
V.27 | |||
V.32 | |||
V.32.bis | . /, . | ||
V.32.turbo | |||
V.33 | |||
V.34 | - | ||
V.34+ | 1 bod 9,8 | ||
V.35 | () | ||
V.42 | . | ( V.*) | |
V.42bis | -//- | ||
V.90 | -//- | , . 33600, 56 000 |
XDSL- , F.
56K - -/-
:
- , F- = 3400,
-. , n-. .
=10,
= 33600 /.
1994 䳺 V.34 - 28800 /. V.32bis :
(preceding). , . . , .
(multidimensional coding) , . , . , V.32bis 6 2400 /. V34 9 3200 ./.
(nonlinear coding) , , (. " ")
(line probing).
. / ( - ), " ", , 1000 - 2000 , V.32 200 -300 )
.
:
▫ MNP 2-4
▫ V.42
MNP 2..4 Microcom . MNP 2- , CRC . MNP 3 - , . MNP 4 - MNP 2,3 .
V.42 (1988) (CRC). V.42 LAPM (Link Access Procedure for Modem). , HDLC. ϳ ' LAPM, , MNP.
:
▫ MNP 5
▫ V.42 bis
/ ' . - dz.
MNP 5 MNP 2..4. V.42bis. V.42bis V.42. -4. , , .