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21. , .
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Network Interface Card NIC) , . , .
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(ISA, EISA, PCI .);
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: ISA (Industry Standard Architecture) - 8(8)- 16- / IBM PC- (8,33 ), EISA (. Extended Industry Standard Architecture) 32 , PCI - Peripheral component interconnect 32 , 33 , PCIE 32| 100.
. OSI, . , .
. 4 16 . ( ).
, , OSI , .
, . , , . , ( ) , . OSI. , MAC- . , . - . , MAC-c -, . , , , MAC- , , . MAC- - , . , . () () OSI. , Layer 2 Switch , L2.
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22. Ethernet. Fast Ethernet.
Ethernet , , , , . . , , , , .
802.3 ( , , ) , ().
(. 3.4) (CSMA/CD) . CSMA/CD . ( ) .
Ethernet.
( ). :
P (preamble) , (101010....). ;
SFD (Start Frame Delimiter) (10101011);
DA (Destination Address), SA (Source Address) . Ethernet . Ethernet- ( Intel 00AA00h, 3Com 0020AFh . .), . DA FFFFFFFFh;
FCS (Frame Check Sequence) ( , ). , Ethernet 46 . (padding). .
.
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Ethernet_II. Ethernet. Type, , (8137h IPX, 0800h IP, 809Bh AppleTalk . .). 05BCh.
Ethernet_802.3. Novell C NetWare. Length, . , IPX. IPX , ( Checksum) FFFFh.
Ethernet_802.2. IEEE 802.3 Ethernet. :
Length ;
DSAP (Destination Service Access Point) - (E0h IPX);
SSAP (Source Service Access Point) -;
Control ; IP- ; IPX 03h ( ).
Ethernet_SNAP. Ethernet_802.2 , SNAP Protocol ID:
OUI (Organizational Unit Identifier),
ID.
. DA . , , , . .
:
SA 05DCh, Ethernet_II;
Length FFFFh, Ethernet_802.3;
Length AAh, Ethernet_SNAP, Ethernet_802.2.
. , , Ethernet .
Ethernet 10 / . Ethernet.
Ethernet Fast Ethernet. :
100 /c;
Ethernet;
.
10Base-T Ethernet , : Fast Ethernet . 100Base-T (802.3u) ( OSI) :
100Base-TX 5 STP Type 1;
100Base-T4 3, 4 5;
100Base-FX .
. :
- ( , , , ),
- .
Ethernet ,
- Ethernet , .
- Ethernet , 100 /.
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Fast Ethernet Ethernet .
Fast Ethernet , , 5 3, Ethernet ( ), , . Fast Ethernet , , Ethernet, , , , .
Fast Ethernet Ethernet: 30-40%, CSMA/CD; ; .
Fast Ethernet , ( Fast Ethernet , Ethernet , ). , Ethernet Fast Ethernet, ISA: " " 10 .
100 /c , Fast Ethernet ( Fast Ethernet, - ).
, , Fast Ethernet. "" , , FDDI ATM.
, 250272 , - 412 2 .
Spanning Tree .
, Fast Ethernet , :
FDDI;
Fast Ethernet .
23. Token Ring. 802.5.
Token Ring ( ). . :
;
, , , ();
.
Token Ring : Abort ( ); Token (); Data/Command Frame (/- ).
:
SD (Start Delimiter) . , ; , , . .
AC (Access Control) . : PPP T M RRR, PPP - , T - , M - , RRR - .
, ( 0 7, 7 - ). , , , . , , , , . .
0 1 .
1 0 , . , 1, , . , . , . , .
FC (Frame Control) . . , . .; MAC LLC . MAC 6 .
DA (Destination Address) . broadcast-, multicast- unicast-;
SA (Source Address) ;
, - (, IPX). . , , . , , , () . , . Token Ring ;
10 . TR 1 4/ 4 , TR2 . 16/ 16
FCS (Frame Check Sequence) , FC, DA, SA ;
ED (End Delimiter) . , . FCS;
FS (Frame Status) . A (Address Resolution) C (Frame Copied). 0, . -, A , .
. , , , , . .
, .
, . , , . , .
: 4 16 /. Token Ring , . . , , .
Token Ring , , .
MAV 750 260.
24. .
:
,
,
, ,
,
,
. .
Internet:
TELNET , ,
; , ;
FTP (File Transfer Protocol)
( ), , ;
HTTP (Hypertext Transmission Protocol)
,
WWW- WWW-;
SMTP (Simple Message Transfer Protocol)
;
NFS (Network File System) ,
Unix- , . . . + 1 .
25. -.
- (Client-server) , (), , , . , .
3 : , .
. . , . .
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2 -.
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26. -.
, . , .
:
:
(PL) , , . , , , .
(Database Manager System) (- - (Access Layer - AL))-
- (BL) , . , - .
-:
. = PL + BL. . RDA Remote Data Access.
Internet, web-. = PL.
- BL.
, , , .
, , , , , . - . , - - , .
, . COM/DCOM/ ActiveX CORBA/DCE/Java. Win32 (Windows 95/NT/CE), (, , Java). ( ) , , . PL, BL, AL. - , , . , , (Transaction Process Monitoring), (Security) Internet (Fire-wall), Internet (Web-access), (Reporting), (Decision Support), (Event Alerts), (Replication), (Mailing) . , -, (Application Server - AS). , BL- , AS , , , .
COM (. Component Object Model ; [ ]) Microsoft, , .
DCOM (. Distributed COM) Component Object Model .
OLE (. Object Linking and Embedding, oh-lay []) , .
1996 Microsoft ActiveX.
OLE . , , OLE-. MS Office.
27. . .
- , : ; ; ; ; ; , ; ; ; ; .
, , - .
, , , . : control, management, maintenance administration.
, ( control ) , , , .
(management) . , . : , , , , , .
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(administration) , . , , , , . , , . .
28. .
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4. () , . , , , .
30. .
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, , => . : FTAM ( OSI), NFS, FTP TFTP ( TCP/IP), NCP ( Novell NetWare ), SMB ( Microsoft IBM).
, . - ; . , "" .
, , :
( , , , ; NT, Unix, Solaris);
( , , , , ; LAN Manager, LAN Server, ENS, NetWare Dos),
.
31. .
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32. RAID-.
. - , RAID.
RAID (. redundant array of independent disks () ) , , . . / / (RAID 0).
- , . , RAID- .
RAID-: RAID 0, 1, 2, 3, 4, 5, 6, 7. , RAID 10, 0+1, 30, 50, 53 ..
RAID :
1) , , . .
2) , . RAID , . . . : , , . .
3) . . : RAID . . RAID-, .
4) . , , . ? . . . 1 , 512 ( ).
5) . I , (I+1) . , RAID- (I+1) . I+1 XOR . XOR I+1, .
RAID:
1) RAID 0. .
, , ( ) . , - .
+ ( I/O)
- RAID 0 RAID 0 , . . .
2) RAID 1.
, , , .
+ ();
+
- - 100%
3) RAID 2. . . : , , . , , , RAID 0, .. . , - . ECC .
+ .
RAID 2 , , , 7. ( n=3 4 ), . 30-60, 11-19%.
.
4) RAID 3. .
RAID 3 ( ) . . RAID 2 , , , , .
RAID 3 RAID 2: .
+ ;
+ .
- => .
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5) RAID 4. . RAID 4 RAID 3, , , . , . - , .
+ ( , );
+
- - .
6) RAID 5. . RAID 4, .
+ ( , );
+ ;
+, RAID-4 .
- - , .
- RAID 0 10
- , RAID Reconstruction ( RAID ) , -