InternetComm

Download Report

Transcript InternetComm 

Computer Network (電腦網絡)

A computer network is set of two or more
computers connected together.

Advantages:
– communicating with other users
– sharing resources (e.g., files, printer)
Local Area Networks (LAN)
Wide Area Network (WAN)
LAN
LAN
LAN
High Speed Link as a Backbone
LAN
LAN
LAN
Internet (國際互聯網)


A global interconnection of networks
connection via:
– telephone lines
– optical fibers
– radio links
Internet Terms

Modem (Modulator/demodulator)
– an electronic device for converting between
serial data from a computer and audio signal
suitable for transmission over telephone lines
Internet Terms

Modem (Modulator/demodulator)
Types:
– external modem
– internal modem
– wireless modem
Internet Terms

TCP/IP
– data are broken down into packets and sent
across the Internet, it is then recombined and
checked the correctness of data.

UNIX
– a multi-user, multitasking operating system
developed in AT&T Bell Lab.
– a system software used by most server.
Internet Terms

ISP (網絡供應商)
– a business that supplies Internet connectivity
services to individuals and other organisations
Example
– IMS
– CTI
– iCable
Internet Terms

DNS (網域名稱系統)
Domain name address
– used by human users
– e.g., “www.hknet.com”
IP address
– used by packet routing software
– e.g., “202.67.240.222”
Internet Terms

URL (劃一資源定位器)
– address for a document or site on the Internet
e.g., http://www.hssc.edu.hk/~f98123/

HTTP (超文本傳送協定)
– the client/server protocol used to access
information on the WWW.
Internet Terms

POP (郵局規約)
– Post Office Protocol
– a standard used in receiving email

SMTP (簡單郵遞傳送規約)
– Simple Mail Transfer Protocol
– a standard used in sending email
Internet Terms

HTML (超文本標記語言)
– a language used for documents on the WWW.
Example
<html>
<head><title> … </title></head>
<body> … </body>
</html>
Internet Resources

Email (電子郵遞)
– message sent and received electronically via
telecommunication links between computers.

World Wide Web (全球資訊網)
– uses a multimedia interface to link to resources
located worldwide
Internet Resources

Newsgroup (新聞組)
– a topic-specific forum where people can post
questions, news, and comments, or read and
respond to such postings

IRC (互聯網傳達對話)
– a service that enables an Internet user to
participate in a conversation online with other
users.
Internet Resources

BBS (電子公告欄)
– a system equipped with one or more modems or
other means of network access that serves as an
information and message-passing centre for
remote users.
Internet Services

Telnet
– runs programs on remote computers

FTP (File Transfer Protocol)
– transfers files between local and remote
computers
TCP/IP
Server
file
Client
file
HTTP
Client
Server
broadband
adaptor
Client
modem
WWW
Client
modem
Free

Web Space
– http://xoom.com/webspace/

Web Counter
– http://fastcounter.linkexchange.com/

Guest Book
– http://www.guestbook.de

Graphic Files (gif, applet, …)
– http://www.rogergifs.com/graphics.html