NETWORK SYSTEM

—  NETWORK SYSTEMS

—  NETWORK

Ø  Set of interconnected computers that through hardware & software technology, work cooperatively for the  purpose of information & application program interchange.

Factors of any Network:

            1. Hardware - physical connection(LAN Card), physical linkage(cable wires).

  2. Software - allows different computers to make sense of electronic signals and data streams sent back and forth across the wires.

—  Network functions

 1. File transfer

 2.information availability

 3.resource sharing

 4. online transaction

 5.provision of a powerful communication among employees

 6. interactive environment

 7.education & entertainment

8. e-mail

Storage and Data Integrity 

—  Network Security

Ø  Data or information on a network is a valuable property to its owner. Loose or damage to health care data can be costly and can create serious legal liability.

Ø  Common Security Used:

—  Password

—  Finger/hand print  and retina scanner

—  Firewall

—  Encryption (changing data into a cipher or a code)

—  Type of networks

—  Local Area Network (LAN)

Ø  Data network intended to serve a single building or a group of building in close proximity.

Ø  Works thru physical wiring.

Ø  Fast file transfer through wires.

—  Wide Area Network ( WAN)

Ø  System of connected computers spanning a large geographical area.

Ø  Usually constructed with serial lines, telephone lines, satellites and FDDI(fiber-optic distributed data inference).

—  The Internet

Ø  Widest among WANs

Ø  Networks of networks

 How the internet works?

—  How Internet works?

—  Steps in Internet Navigation

1.    Begins  by typing the URL of the page into a Web browser, or by following a hypertext link to that page or resource

2.    The server-name part of the URL to be resolved into an IP address by the global, distributed Internet database known as the Domain name system or DNS

3.    The browser then establishes a TCP connection with the server at that IP address

4.    an HTTP request to be sent to the Web server

5.    the Web browser then renders the page as described by the HTML, CSS and other files received, incorporating the images and other resources as necessary

—  Glossary of Internet Terms

1.    Address – the location of internet resources.

2.    Applet – a little application program that can be downloaded over a network and launched on the user’s computer.

3.    Bandwidth – a measurement of the volume of information that can be transmitted over a network at a given time.

4.    Browser – a program run on a client computer for viewing WWW pages.

5.    Cache – a region of memory where frequently accessed data can be stored for rapid access

6.    CGI(common gateway interface) – the specification from how an HTTP servers should communicate with server gateway application

7.    Chat – a system that allows for online real time communication between internet user

8.    Client – a program that connects to and request information from a server

9.    Cookies – collective name for files stored on your hard drive by your web browser that hold information about your browsing habits

10.  Dial-up connection – a connection to the internet via phone and modem

11.  Direct connection – connection made directly to the internet

12.  Domain -  .com, .org, .info, .net

13.  Domain name – internet name (yahoo, google)

14.  Download – process of copying data files from a remote computer to a local computer

15.  FTP(file transfer protocol) – set of rules for exchanging files between computer via the internet

16.  Gateway – computer hardware and software that allow users to connect from one network to another

17.  IP address – every computer on the internet has a unique identifying number