1. OSI

2.

:

• OSI

3. CISCO 4. 5.

/

6.

7. ISO

ISO: ( International Organization for Standardization )

OSI: ( open system interconnection )

20 70 ISO OSI

8.

1. , .

2. , , troubleshooting

3. ,

4.

9. OSI( ) 10. OSI ( ) 11. Telnet SMTP HTTP FTP 7 (Application) 12. Telnet SMTP HTTP FTPASCII EBCDIC JPEG

6 (Presentation)

• /

13. Telnet HTTP ASCII EBCDIC JPEG

Operating System/ Application AccessScheduling

5 (Session)

14.

Telnet HTTP ASCII EBCDIC JPEG Operating System/ Application AccessScheduling 15. EIA/TIA-232 V.35

1 (Physical)

• 0 1

16. 802.3 / 802.2 HDLC EIA/TIA-232 V.35

MAC

2 (Data Link) 17. 802.3 / 802.2 HDLC EIA/TIA-232 V.35 IP IPX

MAC

3 (Network)

18. TCP UDP 802.3 / 802.2 HDLC EIA/TIA-232 V.35 IP IPX

MAC

4 (Transport)

19. TCP UDP 802.3 / 802.2 HDLC EIA/TIA-232 V.35 IP IPX

MAC

20. PDU

PDU protocol data unit):

:message

transport layer : segment

Network layer:packet

Data-link layer:Frame

Physical layer:bit

21.

OSI

PDU ( ,Protocol Data Unit)

22.

encapsulate/encapsulation -----

23. LLC+ IP + TCP + MAC IP + TCP + LLC TCP+ IP TCP 0101110101001000010 LLC IP FCS FCS 24. LLC+ IP + TCP + MAC IP + TCP + LLC TCP+ IP TCP 0101110101001000010 25. A B 26.

Ethernet 802.3 V.35 EIA/TIA-232 27. Ethernet/802.3 10Base2 10Base5 10BaseT 28.

29.

A B C D 30. 31. NIC HUB UTP PC 32.

collision

collision domain

(broadcast domain) router

33.

CSMA/CD

34. CSMA/CD

/ CSMA/CD carrier sense multiple access/collision detect) CSMA/CD

35. CSMA/CD

JAM

36. CSMA/CD

CSMA/CD

37.

• (SAP )

EIA/TIA-232 v.35 Ethernet Frame Relay HDLC 802.2 802.3 38. MAC

MAC media access control): MAC , frame

MAC

1. FCFS first come first service)

2. Token

MAC 802.3802.5FDDI fiber distributed data interface) LAN

39. LLC

LLC logical link control): SAP

LLC 802.2

802.2 LLC

40. SAP

SAP Service Access Point LLC

41. ( ) FCS 2 6 6 4

• 0000.0Cxx.xxxx

IEEE MAC - 802.3 Ethernet II Type 802.2.

• MAC

8 # 42. ( ) SAP SAP FCS 1 1 802.2 (SAP) MAC - 802.3 Ctrl 1 or 2 3 2 SAP AA SAP AA 1 1 802.2 (SNAP) Ctrl 03 1 or 2 OR OUIID 43. 1. 2. OSI , OSI MAC 44.

1 2 3 1 2 4 45.

46.

-

47.

1. Store and forward

2. Cut-through

DA 6 (DA )

48.

3. Fragment free cut-through

64

64B

64 )

64

49.

IP, IPX EIA/TIA-232 v.35 Ethernet HDLC 802.2 802.3 50. ( ) IP

• 172.15.1.1

51. 52.

1. CPU RAM IOS

2.

3.

4. LAN WAN CONSOLE

53.

IP IP

-MAC MAC MAC

- IP

54. ( ) 11111111 11111111 00000000 00000000 10101100 00010000 01111010 11001100 172.16.122.204 255.255.0.0 172 16 122 204 255 255 0 0 55. 10.0.0.0 20.0.0.0 40.0.0.0 S0 S0 E0 1 0 0 1.0 4.0 1.3 E0 4.3 S0 2.2 E0 20.2.2.1 S0 4.1 40.4.4.2 10.1.1.1 1.2 10.0.0.0 20.0.0.0 40.0.0.0 E0 S0 S0 0 0 1 56.

WAN

57.

IPX IP SPX TCP UDP 58. , ( ) 59. OSI

OSI

60. ? ? 61. 1444 1114 62.

63.

WAN :

WAN

( ) / , T1 /ISDN 0 64.

:

• OSI

65.

• 1 .OSI ?

• 2.

• 3. ?

• 4.