1. Defining Networking
Chapter 2

2. Contents Explain the goal of networking
Explain the difference between a server and a client system
Define a network resource

3. Introduction

4. What is Networking?
A group of computers connected together to share information

5. What is the Goal of Networking?
To make a resource shared by a remote system act as a resource on a local system

6. The Birth of Networks

7. Mainframe Computers
Mainframe computers were very large, expensive computers
Designed for massive number-crunching jobs
Designed to support multiple users
Programs were loaded using punch cards or magnetic tape
Users submitted jobs and returned an hour or more later to get a printout of their job

8. Dumb Terminals
Dumb terminals were CRT terminals along with keyboards used for input and output
No computing power – just a way to talk to the mainframe computer
A single mainframe could support dozens of dumb terminals
PCs have replaced dumb terminals in mainframe environments. They use special terminal emulation software that looks and acts like a dumb terminal.

9. Late 1960’s and 1970’s
Mainframes began to use mass storage (hard drives) and more sophisticated operating systems
Users could share common data
The Secret Life of Mainframes
Even though PCs have pushed mainframes aside, there are still companies making mainframe computers. They are used to host applications and to warehouse data. Search for mainframe on the following web sites:

10. Pre-Networking Issues
How could mainframes that were many miles apart be connected?
How could totally different machines using different operating systems, data formats, and interfaces be connected?

11. Modems
Mainframes that were physically separated by great distances used telephone lines to communicate
Modems enabled a user to connect a dumb terminal to a far-off computer
Even though dumb terminals are virtually extinct, modems are still alive and well – in PCs.

12. Mainframe User Interface
Emphasize that this is still not networking. Using a dumb terminal connected to a far-off computer is not networking, but the attitude of long distance communication is important.

13. Cross-platform Support
Terminal manufacturers began to develop standards that enabled terminals from different companies to interact
Before standards you might a different type of terminal to connect to each mainframe

14. ARPA Advanced Research Projects Agency (ARPA)
Now called Defense Advanced Research Projects Agency (DARPA)
Created in 1958 by President Eisenhower
Created the first network called ARPANET
DARPA is a consortium of federal organizations and researchers working for the U. S. government. Visit their web site at

15. ARPANET Connected four mainframes together in late 1969
Provided two types of data transfer:
File Transfer Protocol (FTP) used to transfer files
Telnet enabled a user to log in to another mainframe through their local mainframe
One connection enabled access to all of the other computers
ARPANET slowly evolved from four mainframes connected together to today’s Internet! For more details visit:

16. Networking PCs
When PCs first came out, groups of PCs close to one another were connected to form a local area network (LAN)
The only major difference between the Internet and a LAN is its size!

17. The Goal of Networking

18. Goal of Networking A network consists of more than one computer
The early goal of networking was to share folders and printers
Later PCs would learn to share web pages, , FTP, and even desktops

19. Networks are used to share resources.
How Do We Share?
Whether we are accessing a web page or printing to a remote printer, we require data transfer between your local computer and another device
Resource: anything a device on a particular network wants to share with other systems
Folders
Web pages
Printers
No operating system allows you to share individual files! They allow you to share folders, and then to share a file inside that folder.
Networks are used to share resources.

20. Sharing Resources I’m a client! I’m a server! Server Client
A system on a network that shares resources
Client
A system on a network that accesses a shared resource
I’m a client!
I’m a server!

21. Servers
Since servers must serve many clients they often are much more powerful than your typical PC

22. Software
For a computer to share its resources it must run a server program
File servers
Print servers
Web servers
A client computer must run client software

23. Microsoft Servers
Microsoft makes many different versions of Windows with different types of server software
Microsoft Exchange Server
Microsoft SQL Server
Internet Information Server
Most network operating systems enable a system to act as both a server and a client at the same time
Exam Tip:
The Network+ exam tests your understanding of clients and servers. Make sure you’re comfortable with the fact that in order to share any type of resource you need both a client and a server.

24. Clients and Servers We’re all servers! We’re all clients!
That’s right!

25. Making Shared Resources Useable

26. Sharing a Resource
The serving system must ensure its serving software is started
Then you must define what it is you want to share
It must be given some kind of name or address
Finally, you must decide what users may do with the shared resource
Permissions

27. Starting Server Software

28. Giving a Shared Printer a Name

29. Accessing a Shared Resource
Once a resource is made available, then a client must access it
Define the name of the shared resource
Look in Network Neighborhood or My Network Places to find the name of shared folders or printers
Use a search engine to find the name of a web site
Shared resources act like local resources

30. Name of Servers

31. The Goal of Networking A network must:
Have shared resources
Have a client and a server
Have shared resources that act like local resources
The goal of networking is to make a resource shared by a remote system act as a resource on a local system.