MINDPRIDE Computer Services

 
Home | About Us | Our Services | Contact Information | Tutorials, Articles & Dictionaries | Site Map

HOME 

 

About Us

WhyUS

Services

Virus Alerts

 

Contact

Estimates

Refer A Friend

Site Map

 

Links

Privacy Policy

Disclaimer

MakePayment

 

What is a Network?

Network Center

Networks 101: What is a Network?
September 14, 2000

Author: Thomas Jelen



You have probably heard of a computer network. Maybe you even have one (perhaps you've heard people say, "No e-mail today -- the network's down" or "No Internet today - the router isn't working"). Maybe you need one (you often hear people say, "Can you turn the printer switch to letter 'D'" or, "Can you pass me that disk"). Whatever your needs, you may be wondering, "What exactly is a network?"

In the simplest terms, a network consists of two or more computers that are connected together to share information. All networking, no matter how complex, builds off this simple system. Though this may seem like a basic idea, the concept was a major achievement in communications.

What Makes Up a Network?

A network typically includes four things (besides the computers themselves):
  • protocol: a set of communication rules to make sure that everyone speaks the same language
     
  • network interface cards (NICs): cards that plugs into the back (or side) of your computers and lets them send and receive messages from other computers
     
  • cable: the medium to connect all of the computers together
     
  • hub: hardware to perform traffic control

(Note: The key word is "typically." Wireless networks obviously don't use cables and NICs aren't necessary for small networks that use parallel/serial ports. But the basics still apply.)

How Does a Network Work?

How does one computer send information to another? It is rather simple. The diagram below shows a simple network:

Simple network diagram

If Computer A wants to send a file to Computer B, the following would take place:
 

  1. Based on a protocol that both computers use, the NIC in Computer A translates the file (which consists of binary data -- 1's and 0's) into pulses of electricity.
     
  2. The pulses of electricity pass through the cable with a minimum (hopefully) of resistance.
     
  3. The hub takes in the electric pulses and shoots them out to all of the other cables.
     
  4. Computer B's NIC interprets the pulses and decides if the message is for it or not. In this case, it is, so Computer B's NIC translates the pulses back into the 1's and 0's that make up the file.

Sounds easy. However, if anything untoward happens along the way, you have a problem, not a network. So, if Computer A sends the message to the network using NetBEUI, a Microsoft protocol, but Computer B only understands the TCP/IP protocol, it will not understand the message, no matter how many times Computer A sends it. Computer B also won't get the message if the cable is getting interference from the fluorescent lights, or if the network card has decided not to turn on today, etc.

Network Classification

Like snowflakes, no two networks are alike. So for the sake of discussion, it helps to classify them by some general characteristics. A given network can be characterized by its:

  • size: the geographic size of the network
     
  • security and access: who can access the network and how access is controlled
     
  • protocol: the rules of communication in use on it (for example, TCP/IP, NetBEUI, or AppleTalk)
     
  • Hardware: the types of physical links and hardware that connect the network


Size (LANs and WANs): regarding size, networks are generally lumped into two categories, local area networks (LANs) and wide area networks (WANs)

A LAN is primarily defined by geography, and is typically housed in one building or campus. A WAN, on the other hand, is a network that joins many LANs together using super special, highly secret, WAN technologies, but we will delve into that arena some other day. Hopefully you're still reading. Because they are so common, LANs are usually further divided into two major types:

peer-to-peer: A peer-to-peer network doesn't have any dedicated servers or hierarchy among the computers. All of the computers on the network handle security and administration for themselves. The users must make the decisions about who gets access to what. For more information, see article Networking 101: Peer-to-Peer Networks.
client-server: A client-server network works the same way as a peer-to-peer network except that there is at least one computer that is dedicated as a server. The server stores files for sharing, controls access to the printer, and generally acts as the dictator of the network. For more information, see article Networking 101: Client-Server Networks.



Protocol

As stated above, the protocol of a network is the set of guidelines for inter-computer communication. Two computers with different protocols won't be able to communicate with one another (imagine Ralph Nader and Pat Buchanan in the same room). While many computers have the ability to interpret multiple protocols, it is important to understand the different protocols available before deciding on one that is appropriate for your network.

Hardware

While some theoretically-minded people would claim that the hardware involved in a network isn't extremely important, they probably haven't ever actually dealt with setting one up. Hardware is important. While in theory, every hub should send and receive signals perfectly, that isn't always the case. And the problem is that if you ask two network administrators what hub they recommend, you will probably get two entirely different, yet passionate answers. From picking the cable (optical fiber, coaxial, or copper), to choosing a server, you should find the most suitable hardware for your needs.

 

 

Basic Hardware:

This page covers the basic components of networking PCs in the home.  Networked PCs can share files, printers and internet access.  This type of network is considered a LAN (Local Area Network).

 A wired network will generally consist of at least two computers, Ethernet cable, a hub or router, and NICs (Network Interface Card) in each PC.  You can connect two computers together via a crossover cable and bypass the hub.  But if you have multiple PCs then you'll need those extra ports on the hub or router.

A wireless network, sometimes referred to as 802.11b is the same principle, only instead of a hub, you'll use a wireless router or WAP (Wireless Access Point).  A wireless bridge can connect a wireless network to an Ethernet network.  This is handy if you have computers in the attic or basement and don't want to run wires through walls.

Configuring NICS:

If you do not use a router, your main computer will require two NIC cards.  One leading to the internet and one leading to the LAN.  The internet NIC will usually need to be configured for DHCP to receive an IP address automatically from the ISPs server.  However, the LAN card must be assigned an address, usually 192.168.0.1  / 255.255.255.0.  Now this main machine will have to have Internet Connection Sharing turned on.  Each PC on the LAN will need then to be configured to receive its IP address from the main PC, which will act as a DHCP server.  This will ensure that all computers are on the same subnet.  

Hardware Router 

You might decide to spend the extra money for a router to share internet access.  You will no longer need the hub, and you also benefit by having a hardware barrier between your LAN and the outside world.  The internet only sees the external IP address of the router, making your internal computers virtually invisible.  This is a great security feature.

In this setup, your router will have an external address and the 192.168.0.1 address for the LAN.  It will provide DHCP for the other PCS, so your main computer will no longer need to be on for other PCs to receive internet access, share files or use the printer.    

 

  Services What We Offer Areas Covered Rates & Discounts
Estimates Maintenance Plans Links Phone Tech Support
About Us Refer A Friend Why Us? Reference Dictionaries Tutorials
Privacy Policy Service Protocol Disclaimer Contact Us

Web Page Designed By  ADAM
Copyright 1981 - 2008
MINDPRIDE CONSULTING All rights reserved.
Revised: November 21, 2007