記錄的地平線

Layer 7

Application

Data

Layer 6

Presentation

Data

Layer 5

Session

Data

Layer 4

Transport

Segments

Layer 3

Network

Packets

Layer 2

Data Link

Frames

Layer 1

Physical

Bits

Layer 7 Application

Layer 4 Transport

HTTP    80

²  Segments and reassemble

FTP      21

TCP  (connection-oriented)

TFTP     69

ftp ; telnet ; smtp ; http

Telnet    23

UDP  (connectionless)

SMTP    25

tftp ; DNS

Layer 3 Network

Layer 2 Data link

²  Sources and destination address

²  Data Packets

²  Date Frames

²  MAC Address

IP (Internet Protocol)

  connectionless

  Internet

Reduce traffic congestion

Flow control

Error detection

IPX (Internetwork Packet Exchange)

  connectionless

  Novell Netware network

EQ: Switch ; Bridges ; Network cards

EQ: Router

Layer 1 Physical

EQ: Repeaters ; Hubs