3

, , (Twisted Pair) , , (Electromagnetic Interference, EMI)

, , ,

(Shielded Twisted Pair, STP) (Unshielded Twisted Pair, UTP) (Screened Twisted Pair, ScTP)

, ,

,

,

, 1 , 2 , , 4 , 1

, Cat 5, 100 Mbps, Cat 6, 1000BaseT , 1000 Mbps, 2.4 Gbps

EIA/TIA 568B ,

, , ,

, (Coaxial Cable) 10Base2 , RG58 A/U ,

RG58 A/U (Stranded Copper), , , , , , ()

(), () , , , , 200 ,

(Optical Fiber) , ,

(Core), (Cladding), , (Coating), ,

(SMF, Single Mode Fiber), 5 ~ 10 , , , , (MMF, Multi Mode Fiber), 50 ~ 100 ,, ,

2 Gbps, , , , , ,

(AP)()

RJ-45

(Bandwidth) 10 Mbps100 Mbps 1000 Mbps 3 , 3 , 100 BaseTX 10 BaseT , 10/100 Mbps

(Repeater) , , OSI , (Physical Layer) , , , ,

(Hub) 10BaseT 100BaseTX , , RJ-45 Port, Port , 4 Ports 32 Ports , , , Port, Concentrator

(Bridge), , , , , , , , (Bridge)

A B , , AB 1 , 2 , , 2 A C , , A C D , ,,

,

(Broadcast packet), , , , , ,

2 (Data Link Layer) , (Switch Hub) (Multi-port Bridge), Port, , Port, Port Port , Port

2

2 Port ,

(Router) OSI (Network Layer), ,

, LAN1 LAN2

, , , , ,

, , Unix Windows NT/2000/2003 , ,

IP IPX ,

, ISDN , () ISDN ,

, , , NetBEUI (Nonroutable) , (Bridging router, Brouter)

- NAT ADSL (AP)

(Application Gateway)(OSITCP/IP)OSI 1~7