Internet . 1993 . 1776 .
137 , 3
. TCP/IP. ,
Unix, VMS, MS DOS .
NFS. ,
SMTP. Internet ,
. , TCP/IP
, Internet, Internet.
. , Internet2.
VBNS (National Science Foundation, NSF),
NSFnet ,
Internet 80- 90- .
NSF , vBNS (very high speed Backbone Network Service
) Internet-
.
.
-
. IP-over-ATM.
(155 622 /) NAP
(Network Access Points), .
ATM- ASX-1000. ASX-1000
( Cisco 7507) c
.
DECNet DEC.
Pathworks. Pathworks ,
Novell Netware, LAN Manager, AppleTalk. Ethernet, Token Ring, FDDI,
X.25. IBM-mainframes.
CORBA (Common Object Request Broker Architecture)
ObjectBroker .
Relcom ,
. off-line. Relcom
Internet.
4. . . . . .
. Internet, , . .
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-
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-
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: IP-, Internet .. , () , , , NAT.
, .
5. . . . . .
.
6
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:
-
- , .
- , .
- () - .
:
-Ethernet, Fast Ethernet, Gigabit Ethernet
-Token Ring
-FDDI
-100VG-AnyLAN
-Wi-Fi
6. . .
, , , , :
- (program portability), .
- (interoperability)
- (user portability)
, - , .
1. -.
( ) , .
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2.
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:
4. () .
, , . , , . , , (, , ) . -, , . , , : , , .
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-
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7. . . .
(Open Systems Interconnection OSI), (International Standardization Organization ISO). (, , , , , ) , , , , .
. ISO, , , . , , . , . . , .
|
|
OSI : , , , . . , . - , , - , .
(Application layer) . . , . . FTP, X400(, , ), SMTP, POP3 IMAP, Telnet, HTTP, SMB (Server Message Block),CIFS (Common Internet File System).
, (Presentation layer) , "" , , XDR(External Data Representation), AFP (Apple Filling Protocol 6 7 OSI) .
(Session layer) , , , , ( ) .
: AppleTalk Session Protocol (ASP), AppleTalk Data Stream Protocol (ADSP), NETBIOS (Network Basic Input/Output System).
(Transport layer) , . SPX, TCP UDP.
OSI "" (subnet). . , , , , , .
, (Network layer) ( ), , , , . : . IP, ICMP, IPX.
|
|
(Data link layer) , . (), , . HDLC(High Level Data Link Control), {Ethernet, Token Ring FDDI, ATM, Frame Relay X.25 ( , )}.
(Physical layer). - , 0 1. . , - , , ( ..). , 10 BASE-T ( baseband signaling ( , T twisted pair ( ))
, , . . , . .
8. . TCP/IP. .
OSI ISO , RFC (Request for Comment), Internet TCP/IP. TCP/IP-.
TCP/IP- 20 (Defense Advanced Research Projects Agency DARPA).
TCP/IP , . TCP/IP , TCP/IP ISO. , TCP/IP - , . , TCP/IP ISO. TCP/IP .
IV ( ) OSI.
III ( ) , .
II (, ) ISO. "" , .
I , .
. 1.1 , TCP/IP. , TCP/IP ISO, , ISO. , , TCP/IP, ISO. , , ISO, TCP/IP.
. TCP/IP
OSI ISO TCP/IP . 1.1.
1.1 OSI ISO | TCP/IP |
7. | I. |
6. | |
5. | II. () |
4. | |
3. | III. |
2. | IV. |
1. |
9. . , , , . .
|
|
OSI ISO | TCP/IP | ||
7. | I. | FTP, TelNet, SMTP | |
6. | |||
5. | II. () | ||
4. | TCP, UDP | ||
3. | III. | IP | X. 25/IEEE 802.x |
2. | IV. | ||
1. |
(Application layer) . , . . (FTP, X400, SNMP, Telnet ).
, (Presentation layer) , "" , .(XDR, ASN1, DES).
(Session layer) , , , , ( ) .
(Transport layer) , . (SPX, TCP UDP).
OSI . , , , , , .
, (Network layer) , , , , (IP, ARP, IPX).
(Data link layer) , . (), , . (HDLC).
(Physical layer). - , 0 1. . , - , , ( ..). , X21, Ethernet .
- ,
,
- , , .
, TCP UDP.
TCP .
UDP ( ).
- , . IP.
IP .
TCP/IP () , IP- .
: . : .
10. .
, , , . :
, (Physical Media Independent PMI);
, (Physical Media Dependent PMD).
(Media Independent Interface MII). PMD , (Media Dependent Interface MDI), (Physical Layer Device PHY). OSI - .
, . IEEE
(Logical Link Control LLC)
- (Media Access Control MAC)
LLC , , , .
MAC , LLC, . MAC- .
MAC- , . . , . , 32 ( jam-), . MAC- , .
MAC- , , , , . , : , , , . , LLC-, .
(High-Level Data Link Control Protocol HDLC) :
, ( ), , , . , ;
, . , .
DLC :
Point-to-point (), : ;
Multipoint (), ;
Loop (), , , , , ;
Hub go-ahead ( ), . . . .
, , , FCS( ), .
HDLC :
(NRM), , ;
(ARM), ;
(ABM), "" , , , . . - .
.25 , , .
.25 OSI.
.
(LAP-B) , .
.25 .
X. 25 , . X. 25 , . , , - . , LAP-B . . , , . , . , ..
X. 25 , . X. 25 , "", , . , , , X.25 , . , , . X. 25 .
11. . IPX: , , .
- Novell.
- IPX, NetWare.
-
:
Checksum . ;
Length . NetWare (N): Token Ring ARCnet 4202 , Ethernet 1514 . IPX ;
TransportControl ,
. 0 IPX ;
PacketType . , IPX, 004;
DestNetwork , . . , (), ;
DestNode , . . (), FFFFFFFFh;
DestSocket , - . ;
SourceNetwork, SourceNode, SourceSocket , , , , , . IPX ;
Data IPX .
IPX
- NetWare.
- "" . , .
IPX :
;
;
.
, , IPX, , . SPX.
12. . SPX: , , .
SPX (Sequenced Packet eXchange) . SPX
ConnControl , SPX;
DataStreamType , , SPX;
SourceConnID , SPX . SPX;
DestConnID . , , ( ), . SPX;
SeqNumber , . . FFFFh 0, . SPX;
AckNumber , SPX. SPX.
AllocNumber , . SPX.
SPX ECB, IPX.
IPX/SPX NetWare, , . Novell , . , IPX/SPX - , , . , , IPX/SPX Novell , NetWare.
13. . PCP/IP. IP .
Transmission Control Protocol/Internet Protocol (TCP/IP) , . TCP/IP :
, , ;
TCP/IP;
Internet;
intranet , Internet WWW, Internet;
TCP/IP ;
, ;
-.
( OSI) IP
( OSI) IP, , , , . IP , . IP , .. , .
TCP .
UDP , IP, .
TCP/IP .
* FTP,
* Telnet,
* SMTP ( Internet),
* (, WWW) .
MAC-, IP-, DNS-
TCP/IP 2 :
- , , .
MAC- . , . MAC- 6 : 3 . , . . .
- IP-. 4 . . . IP- . . .
IP- , 2 : .
IP -
1 | 3 | 1.0.0.0 | 126.0.0.0 | |
B | 2 | 2 | 128.0.0.0 | 191.255.0.0 |
24 | 8 | 192.0.0.0 | 223.255.255.0 | |
D | 4 | 224.0.0.0 | 239.255.255.255 | |
240.0.0.0 | 247.255.255.255 |
:
0.0.0.0 - IP-. , , , IP-.
255.255.255.255 - .
, "0" .
, "0", .
127.0.0.0-127.255.255.255 - . TCP/IP .
14. . UDP.
UDP (User Datagram Protocol) , , , .
UDP. , , , . , , , .
, , . TCP/IP . , , , () . , , , , .
, , , () .
Internet Assigned Numbers Authority. Internet.
UDP. UDP : , , , .
UDP , , .
UDP , , .
UDP , .. , .
, UDP , .
, , , , , , TCP UDP.
UDP , .
UDP. UDP UDP-, . UDP- , . :
UDP source port -;
UDP destination port -;
UDP message length UDP- ;
UDP checksum UDP-.
UDP- . , . , , IP IP-, .
, ( ) . 8 . , 65535 UDP- (8 65527 ). IPv4 65507 ( 8 UDP- 20 IP-).
15. . TCP ICMP: .
TCP , .
.
TCP .
, TCP , TCP . TCP. "" , .
TCP , ( PSH 1). TCP, , .
TCP .
. . TCP , .. .
TCP ( ). IP- ( ) . .
.
- ,
(SYN).
- , :
;
, ;
, , .
(ACK).
TCP ( )
. ( ) .
2 : " ".
, , , ( ) ( ).
( ) , .. , .
1 , - 1 ( ) .
- , W , . . , (), , .
- , .
( ). , . - .
TCP . , , , , TCP.
(), , . W, N, , N+W. , .
.
TCP. TCP . :
(Source port) 2 -;
(Destination port) 2 -;
(Sequence number) 4 , , ;
(Acknowledgement number) 4 , , ; ;
(HLen) 4 , TCP, 32- . , ;
(Reserved) 6 , ;
(Code bits) 6 , , :
URG ;
ACK ;
PSH ;
RST ;
SYN , ;
FIN ;
(Window) 2 , ;
(Checksum) 2 , ;
(Urgent pointer) 2 , URG, , , ;
(Options) , 3 ; , , ;
(Padding) , , 32- .
ICMP , - IP- .
ICMP - , . , , ICMP . ICMP IP. , , IP, ICMP ICMP.
-, : - -. -, IP- , .
, -, - . , . - - IP-, .
ping, .
. IP-, , , ICMP- " ". . ICMP- , , . 64 .
ICMP, " " (Redirect). IP- , , 64 . , .
16. . . . .
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