.- ,

Glava 6-1

6

6.1

Advanced Research Projects Agency (R)

1960- . ,

: ,

.

..

, , ,

. "

R IP (Information

Processing Techniques Office) h Licklider

.

-

.

-

.

time-sharing,

.

. 1963

.- ,

Glava 6-2

I&IP (Compatible Time

Sharing System), Licklider .

time-sharing

,

. time-sharing

, time-sharing

,

. 1966

,

dial-up .

Paul Baran

Rand tion Donald Wats Davis National Physical Labaratory,

Davis "packet-switching

" . ket-switching

r-t-r ,

.

,

, ,

() ,

.

,

.

IP :

RAND, University of California Santa Barbara (U), Stanford Research Institute (RI),

University of Utah University of California in Los Angeles (UCLA) 1968

kt-switching network.

1969 Bolt Beranek & Newman

(N), Cambridge Massachusetts Company.

-

( )

.

.- ,

Glava 6-3

,

.

1 1969 K I

(Interface message processor) UCLA, UCSB, SRI

University of Utah. .

packet-switching Davis 1961

R, ,

RNET.

.

(network working)

1996 .

,

(Telnet)

(File Transport Protocol - F),

NCP (Network Control Protocol).

1971 15

. ARPANET

( , Ray Tomilson .).

RN N

(/IP) 1982 .

RPANET ,

1978 packet-switching,

. packet-switching -

USN 1978 .

USENET

: N, N

MSFN. NSFN

/IP

. 5

()

"backbone".

packet-switching . ,

.- ,

Glava 6-4

,

,

.

IP ,

. ket-switching

(User Friendly) .

(t nsfer

tol), RN (Conseil Europeen pour la Recherche Nucleaire),

WorldWideWeb - l for a HyperText project,

WWW.

1990 .

.

.

.

6.2 OSI

, .

.

(

, ) .

,

, , ( ,

).

, .

.- ,

Glava 6-5

,

. .. OSI (Open System for Interconnection) ,

:

(application layer) (presentation layer) (session layer) (transport layer) (network layer) (data layer) (physical layer)

, TCP/IP UDP

5 , OSI 5 7

, . IP,

TCP UDP .

OSI 1 2. 6.1 OSI

.

(Transmision Control tl) IP (Internet tl).

IP,

OSI ,

(Simple Mail Transport 1l), N (Simple Network Manage tl), F

(File Transfer Protocol), Telnet (Terminal emulation protocol)

R (Remote Procedure Call), XDR

(External Data Representation) NFS (Network File System).

- I UDP (User

Datagram Protocol),

,

.

IP ( ) 6.1.

.- ,

Glava 6-6

OSI

NF

XDR F, 1net, ,N,R

RPC

, UD

I

RP, RARP

6.1 OSI

()

, ( OSI )

.

:

(hosts), . ,

.

.

.

Hub . .

. Hub-

.

.

(bridges), .

(Local Area Networks LAN).

.

I

.- ,

Glava 6-7

. OSI.

MAC .

(switch), .

Switch-

.

.

(routers), .

. .

(, )

. .

(TCP, UDP, IP )

, .

6.2 OSI ()

( )

.

()

.

PSDU (PLCP Service Data Unit)

MAC H

PHY ( )

MSDU (MAC SDU)

LLC H

H IP

TCP

HTTP

HTML

MAC (Medium Access Control)

LLC (Logical Link Control)

IP

TCP

HTTP

IEEE 802 ()

TCP/IP

PHY H

.- ,

Glava 6-8

(, ) ,

( 6.2).

, ,

, .

: LAN (Local Area Network), MAN (Metropolitan Area Network), WAN

(Wide Area Network), , .

LAN

LAN

LAN

6.3

( 6.3).

.

IP ,

.

.- ,

Glava 6-9

.

, .

(IP Internet Protocol) .

,

(

).

IP ,

IP .

() IP

. (, )

, IP .

.

.

( IP )

(gateways),

internetworking .. .

.

,

,

().

6.3 - IP

.

(

) .

.- ,

Glava 6-10

IP

. IP

.

IP , : IP version 4 (IPv4),

RFC 791, IP version 6 (IPv6), RFC 1883-1887. IP

:

IP . IP ()

;

IP IP ;

;

IP ( ) ,

.

IPv6 IPv4.

(..

IP ).

6.3.1 IP 4 (IPv4)

IP . IPv4

20 .

MSB (Most

significant bit) LSB (Least significant bit) ,

.

.- ,

Glava 6-11

6.4 IP IPv4

6.4 IPv4 .

IP IPv4,

.

IP .

(Version)

( 4 6, .. IPv4 IPv6).

(

), IHL (Internet Header Length)

, 32 (.. 1 = 4 ).

5 ( 5 4 = 20 ),

, 60 .

(Type of Service S)

, ,

. . ,

(

), ,

. File Transfer,

. ToS 3 Precedence , 3

: Delay, Throught Reliability.

,

( bit/sec).

(Type of Service-ToS)

0 4 8 16

19

(Time To Live-TTL)

(Header Checksum)

24 31

IP (Source address)

IP (Destination address)

(padding)

32 = 4 (1 = 8 )

5x4=20

.- ,

Glava 6-12

, default, .

(, , e-

mail .),

, best-effort. ,

best-effort .

(Total Length)

. , 16 ,

65535 (64 kB), .. 0 (216-1).

(Fragment Identification)

,

,

, .

(Flags) 3

.

.

. .

(Fragment Offset)

, I ,

, .

. 13 , 8192

, 64kB.

(Time to Live)

.

hop- .

TTL ,

. 0,

.

,

,

.

.- ,

Glava 6-13

, IP

( TCP, UDP

). (Protocol) .

(Header Checksum)

IP .

,

( Time to Live )

.

IP (Source Address) - IP

.

IP (Destination Address) - IP

, IP .

(Options) ,

. ,

,

. Options .

,

.

6.3.2 IP 6 (IPv6)

IPv6 IPv4. IPv6

. IPv6

128

32 IPv4. , IPv6

IP

( 7 Network Address Translation).

IPv6

IPv6 . IPv6 6.4.

.- ,

Glava 6-14

6.4 IPv6

IPv4,

IP 4.

IPv4, IPv6 QoS (Quality of Service)

. ( ,

, /)

, ( ) IP .

(flow labels)

, IP end-to-end QoS

.

IPv6 .

.

.

. IPv6

(payload length)

0 8 16

(hop)

24 31

(Source Address)

: IPv6 128 , 4 IPv4 .

(Destination Address)

4 12

32 = 4 (1 = 8 )

10x4=40

.- ,

Glava 6-15

IPv4

.

IP IPv6

( , IPv4

Header Checksum, TTL )

.

.

IPv6 IP

4 128 32

IPv4.

(Hop) 8- TTL

IPv4.

, , IPv6 IP

IPv4.

, IPv6 ,

, IPv6 ,

IPv6 . IPv6

, IP.

IPv6 40 .

IP

IPv6 IPv4 ( 20

), . ,

(

IP)

,

IPv6 IPv4.

6.3.3 IPv6 IPv4?

IPv6 IPv4 .

. IPv6

.- ,

Glava 6-16

IPv4

,

.

IPv6 ,

.

IPv4

IPv4 . plug-and-play

IPv6

IPv4

. IPv6

IPv4 IPv6 (.

IP ).

IPv6 stacks IPv4 stack

IPv6 stack.

IPv6 IP ,

IPv6. . IPv6

IPv4

IPv6

QoS .

6.4 IP

( IP )

IP . IP

. /IP ,

32 :

(network number) (host number).

.- ,

Glava 6-17

,

, Network Information Center (NIC).

, NIC ,

IP

.

IP 32 ( IPv4,

IP IPv4 ), 4 ,

( 194.149.144.1).

0, 255.

IP 5 , , , D .

, .

, 6.5.

6.5 IPv4

IP . IP

126 16 ; B

16382 65534 ; C 2 254 .

, . , C

255 ().

,

5 IP (classful IP addresses):

A: 7- /24- 0xx 0 126

loopback ( IP ) 127

B: 14- /16- 10x 128 191

C: 21- /8- 110x 192 223

D: 1110x 224 239

E: 1111x 240 254

broadcast () 255.255.255.255

.- ,

Glava 6-18

7 , C 21

,

.

D . IP ,

D.

.

,

.

E .

, IPv4 / -

ID ( ) ID (

).

32 unicast .

, B C , .

IPv4 . 1990- .

IPv4

.

Classless Inter-Domain Routing (CIDR)

.

.

.

IP (CIDR) IP 64

:

IP 32 , (mask) 32 .

, IP ,

, IP

IP . ,

:

.- ,

Glava 6-19

1) a.b.c.d/255.255.255.0 ( ,

IP );

2) a.b.c.d/24 (

32- , - /24

255.255.255.0, 24

IP 1)

IP :

IP = 10.24.17.198 / 255.255.248.0 (IP / IP )

0A.18.11.C6 0A.18.11.C6

FF.FF.F8.00 00.00.07.FF

0A.18.10.00 00.00.01.C6

= 10.24.16.0, IP = 0.0.1.198

6.5 IP

IP (, )

(, ).

IP .. . IP

.

.. IP

IP ,

IP ,

IP . IP

(.. IP )

IP (..

IP ) , IP ()

(

).

.- ,

Glava 6-20

:

() ,

.

, (.. ):

( 2 layer 2): ( direct delivery)

o , IP ()

.. (:

), IP

o ?

IP ,

.

( 3 layer 3): (store and forward):

( indirect delivery)

o ,

(

TTL > 0)

o ?

.. (table-driven routing).

,

(next-hop routing),

IP . , :

(default routes) .

() IP

. ,

.- ,

Glava 6-21

(

).

6.6.

6.6 ()

, ,

. ,

. , IP ,

( , ),

( , ).

IP ,

IP .

IP

RouteDatagram (Datagram, RoutingTable)

IP D N;

if N ( IP )

D

else if host-specific D

else if N

else if default

default

else (routing error);

.- ,

Glava 6-22

10.0.0.0

30.0.0.0

50.0.0.0

80.0.0.0

10.0.0.2

30.0.0.5 30.0.0.9

50.0.0.5 50.0.0.6

80.0.0.1

- - -

( ) ( )

30.0.0.5

30.0.0.050.0.0.0.10.0.0.080.0.0.0 50.0.0.6

-

6.7 IP

6.7

. 4 . ,

. IP

30.0.0.0 50.0.0.0 ( ,

, IP ), , ,

IP 30.0.0.0

IP

(MAC Medium Access Control ) , IP

( ,

),

. ,

IP 10.0.0.0,

IP

30.0.0.5 , .

(

).

.

.

( ) :

.- ,

Glava 6-23

, IP IP

IP , IP

( 6.2);

IP , IP ( ,

, , WiFi .).