Networks and Networking
Important 2007 Note!
- ITA students - you only need to know a fraction of the networking information that was expected in the old IPM course - specifically, you only need to know "an overview" of types and characteristics of networks (such as LAN/WAN, P2P/Client-server, )and the functions of network operating systems. Also you need to know the suitability of types of "transmission media" including cables and wireless. You do not need to know topologies or protocols!
- Software Development students - you need to know the lot!
Hold your breath. This can get pretty technical.
Computer networks are no more than computers that are linked together so they can communicate.
If that’s all there was to it, this would be a very short chapter indeed; but, as you may have feared, you need to know a lot more about the world of networking.
It's how computers are linked together that can get complicated. Let's see if I can explain it in less than 100,000 words.
Let's start with a computer.
To connect a computer to a network, you need a network interface card (NIC) in it. This is what the network cable gets plugged in to.
Say hello to NIC.
Computers can be linked together with cables or the connection can be wireless (through radio communication). Wireless networking is the latest hot thing in the Info/Communications world through Bluetooth, WAP and 3G mobile phones.
The 'logical' shape of a network's wiring is an important part of its definition. This is called its topology (e.g. bus, ring, star, tree, mesh).
Networks need to connect cables together. They use switches and hubs to do this. To protect the network from the outside world, they use routers.
Networks can also be described by the types of servers at their core (file servers, application servers).
Peer-to-peer networks are distinguished by the lack of a server in the network.
A client-server network handles information requests from other computers.
The way the network is wired and how signals behave are also important: the main types are Ethernet and Token Ring and ATM. Ethernet is the most popular and most widely deployed network technology in the world.
Overview of network types - LAN, WAN etc
The rules used by the network for sending data is called a protocol. Protocols are to computers what language is to humans. For two devices on a network to successfully communicate, they must both understand the same protocols. Examples of protocols are IPX/SPX, and TCP/IP.
Network size is another factor in describing a network: there are local area networks (LAN) , metropolitan area networks (MAN) and wide area networks (WAN). When WANs get interconnected, you have the Internet.
Of course big networks need a way to communicate once cables aren't long enough.
The software used to control a network is called a network operating system (or NOS). The NOS usually runs on a file server or application server.
If you want to get a message from one part of a network to another, you'll need to know about network addressing - including URLs.
A server needs a lot of security.
Are you wondering why networks are good? Read here! One of the benefits is the low cost of making long distance phone calls over the internet using VoIP (Voice Over IP) at a fraction of the cost of normal phone calls.
Here's a technical summary of how you might connect to the Internet from home and from school.
There. That wasn't too hard, was it?
See a summary of the main points in brief.
Also see...
Bits of the Internet: DNS, WWW, Email, Usenet, Search Engines etc
Servers, blades, info appliances, peer-to-peer
Netiquette: keeping yourself nice on the net
Search engines - how they work, social implications
Internet tools you have on your computer
NETWORK NEWS SNIPPETS
From the real world: using Virtual Private Networks (VPN) to distribute feature films to cinemas. Bye bye to 35mm film reels and projectors!