4

4 , , . 04606023 04606034 06606002 066060151. 1) 2) (1) (2) 3) (1) (2) (3) (4) 1) 1) , , , : 1) , , or 2) , , . , . .

2) 1 (Simplex) . ) TV,

, , 2) 2 (Half uplex) . . )

, , 2) 3 (Simplex) . )

, , 2) 1 . . -(Host-Terminal) . 2-(Client-Server) . . 2) 3--(Peer to Peer) . LAN . 3) . , .

3) 1 , .2 . , .3) 3 . . .4 . . , , .2. (Network : )1) 2) 3) 4) 5) 6)

1) (Analog) (Digital) (Error Control) (Flow Control)

1) (Analog) (Digital) , 0 1 2 .1) 1) (serial) . .PC

1) (parallel) . .

1) (Synchronous system) (Asynchronous system)

1) (Error Control) (Flow Control) ,

2) (Modem)(Hub)(bridge)(router)DSU/CSU(Data Service Unit/Channel Service Unit)

2) (Modem) .

2) (Hub)LAN .

2) (bridge) (LAN) . : LAN : LAN WAN 1. 2. 3. 4. () LANLAN 2) (router)(LAN:) , , . , , .

2) DSU/CSU(Data Service Unit/Channel Service Unit)DSU , PC , .MUX . CSU . CSU .

2) , . . (Bit Repeater) (Buffered Repeater) . , . .OSI , .

3) (Circuit Switching) . (Public-Switched Telephone Network: PSTN) . A B (C) . . : : .

3) (Packet Switching) 2 . . , , . .

4) LAN(Local Area Network)1Km , , , LAN , , , . LAN LAN .4) MAN(Metropolitan Area Network)MAN LAN WAN , MAN WAN LAN WAN . MAN 50Km . .4) WAN(Wide Area Network)WAN , , , LAN .5) (Bus) . , . .

5) (Tree) , , . .ex) cable TV

5) (Ring), (Loop) . . . , . 5) (Star) . I/O .() . . . 5) (mesh) , . . -- . .(, , ) .5) 6) (VAN:Value Added Network) () , . , , , ., , .6) (ISDN : Integrated Services Digital Network) , , , . (B-ISDN : Broadband ISDN) . , , , , ATM(Asynchronous Transfer Mode) .

6) (ISDN:integrated services digital networks) . ISDN 64kbps , 1.5M~2Mbps . TV 10Mbps . LAN 10Mbps (Ethernet) 100bps FDDI(Fiber Distributed Data Interface) LAN 100Mbps ISDN . TV LAN , ISDN 10 ISDN . Broadband ISDN. (ATM:Asynchronous Transfer Mode) 150Mbps 600Mbps , .6) (ADSL : Asymmetric Digital Subscriber Line) ADSL . CATV 3 .

VDSL (very high-data rate digital subscriber line ) .

446) xDSL( . Digital Subscriber Line) ADSL(Asymmetric Digital Subscriber Line) VDSL(very high-data rate digital subscriber line )SDSL(Symmetric digital subscriber line )

FTTH(Fiber To The Home) .6)