OSI
(Open System Interconnection) - , , .
- International Organization for Standardization International Standards Organization, ISO, International Telecommunications Union, ITU, ITU Telecommunication Standardization Sector, ITU-T - .
OSI , . , OSI.
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: UNIX , , (); Novell NetWare - Open Driver Interface (ODI).
Internet , , - . Request For Comments (RFC).
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- Protocol Data Unit, PDU.
- (connection-oriented), (connectionless).
(Physical layer)
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(Data Link layer)
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(Network layer)
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- (routed protocols) ;
- (routing protocols) ;
- (Address Resolution Protocol, ARP) , , . .
IP, IPX.
(Transport layer)
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TCP UDP, SPX.
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(Session layer)
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(Presentation layer)
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(Application layer)
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- ( ATM Forum, 100 , 100 Ethernet Fast Ethernet Alliance);
- (FDDI - , ANSI);
- (ISO, ITU).
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1. (International Organization for Standardization, ISO, International Standard Organization) OSI.
2. (International Telecommunication Union, ITU) .
3. (Institute of Electrical and Electronics Engineers, IEEE) , . 1981 ., 802 . 802.1, 802.2, 802.3, 802.5 Ethernet Token Ring.
4. (Electronic Industries Association, EIA) , , RS-232C.
5. (Department of Defence, DoD) - TCP/IP.
6. (American National Standarts Institute, ANSI) ISO. FDDI, .
Internet (ISO, ITU-T).
Internet Society, ISOC , . ISOC Internet Architecture Board, IAB Internet, TCP/IP Internet.
IAB Internet Engineering Task Force, IETF , Internet Research Task Force, IRTF TCP/IP.
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Internet.
- IETF , , Internet. RFC;
- . 6 , .
- , , , . 4- .
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Internet RFC , RFC Internet.
: TCP/IP, IPX/SPX, NetBios/SMB, DECnet, SNA, OSI. , SNA, Ethernet, Token Ring, FDDI. OSI.
OSI | IBM/Microsoft | TCP/IP | Novell | OSI | |||||
SMB | Telnet FTP SNMP | NCP | X.400 X.500 FTAM | ||||||
SMTP WWW | SAP | OSI | |||||||
NetBios | TCP | OSI | |||||||
SPX | OSI | ||||||||
IP RIP OSPF | IPX RIP NLSP | ES-ES IS-IS | |||||||
802.3 (Ethernet), 802.5 (Token Ring), FDDI, Fast Ethernet, SLIP, 100VG-Any-LAN, X.25, ATM, LAP-B, LAP-D, PPP | |||||||||
, , , | |||||||||
Local Area Network (LAN) - .
Wide Area Network (WAN) - .
Metropolitan Area Network - .
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2. - , , .
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n - (10 , 1);
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3. - - .
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1. (availability) - , . . .
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2. (security) - .
3. (fault tolerance) - .
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2. (scalability) , , .
(transparency) - , , .
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(bandwidth) , , 0,5. .
(attenuation) , . , . , .
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:
A = 10 lg (P/P).
.
= 10 lg P/1 []
, 1 .
(throughput) (/).
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(baud).
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= F log2(1 + Pc/),
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= 2F log2 ,
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(Near End Cross Talk - NEXT) - , , . NEXT = 10 log2P/P.
- . (Bit Error Rate, BER). 10-4-10-6, 10-9.