All about Computer Networking
What is a Computer:
A computer is a programmable machine designed to automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem. An important class of computer operations on some computing platforms is the accepting of input from human operators and the output of results formatted fo...r human consumption. The interface between the computer and the human operator is known as the user interface.
Conventionally a computer consists of some form of memory, at least one element that carries out arithmetic and logic operations, and a sequencing and control unit that can change the order of operations based on the information that is stored. Peripheral devices allow information to be entered from an external source, and allow the results of operations to be sent out.
A computer's processing unit executes series of instructions that make it read, manipulate and then store data. Conditional instructions change the sequence of instructions as a function of the current state of the machine or its environment.
The first electronic digital computers were developed in the mid-20th century (1940–1945). Originally, they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs). In this era mechanical analog computers were used for military applications.
Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space. Simple computers are small enough to fit into mobile devices, and mobile computers can be powered by small batteries. Personal computers in their various forms are icons of the Information Age and are what most people think of as "computers". However, the embedded computers found in many devices from mp3 players to fighter aircraft and from toys to industrial robots are the most numerous.
What is a Computer Network?
Simply put, a computer network is a collection of autonomous computers. The definition is as simple as that. More complex definitions can be found on text books and other websites, but I believe in an approach that should make sense in the simplest way.
If you think about computer network, then you should consider the fact that it simple means various computers connected to each other which should facilitate sharing of resources. This article on computer networks will cover only the basics of what all you need to know on a superficial level. Each section will be explained in detail in later articles.
The Need For Computer Networks
As businesses grows, so does the requirements. Companies that start out small grow into large organizations where they have thousands of offices spread across different parts of the globe. Companies needed a cost effective solution for connecting all their businesses in different places and thus computer networks were invented.
In olden times, a single computer used to process all the requirements of a large organization or university. Gone are those days where centralized computing was the norm. With the advent of technology and the reduction in prices of computers, businesses found it more cost effective to have a lot of computers do the job a single computer did. This proved effective in many ways
Higher reliability
Better efficiency
Ability to troubleshoot better
Reduced latency
These computers were collectively termed as computer networks. These computers had the ability to exchange data between them and share resources. Resource sharing was one of the most important features of computer networks. With resource sharing, computers were able to deliver higher return of investment.
To print a document each computer need not have it’s own printer. Any computer in the network could access a printer, even remotely, when free to print the required information. This also increased reliability because if one computer or printer in a network went down, another computer or printer could take it’s place. As up-time is critical for every business, computer networks began to spread fast.
Types of Computer Networks
Here I will list the various types of computer networks. Details will be given in later articles. This is just n overview for you.
Local Area Network or LAN
Metropolitan Area Network or MAN
Wide Area Networks or WAN
Wireless Networks
Internetworks
Computer Network Hardware
Here are some of the common computer hardware devices that we see in a computer network.
Routers
Hubs
Switches
Network Gateways
Network Firewalls
Adapters
Bridges
NIC or Network Interface Card
Home Computer Networking Tips
Networked computers at home is a common sight these days because of the ease at which you can share resources, share a single internet connection and even play a couple of multiplayer games when you feel like it.
To create a network at home you only need a couple of things:
A router or switch
LAN Cables with RJ-45 adapters
Network adapters on all the computers you want to connect
Yes, the list is that short for home computer networking. Now all you need to do is start measuring the length of each cable going from where the router is to each computer. You want to have cables as short as possible because in some cases signal strength might be influenced by this factor. Also it is desirable to have easier cable management to be able to hide the cables efficiently when the network is finally running. make sure that the cable is sufficiently long enough so that if you need to shift the computers, the network cable can reach that place.
Some people have asked me whether they need professional help and I usually think that you don’t. If all you want to do is share an internet connection you can simply connect the hardware pieces mentioned in the list and in 80 percent of the cases your computers will be instantly connected to the internet. If that is not the case, you will need to use the generally intuitive setup wizard that is integrated into the software part of the router. So, in conclusion I don’t think you need an expert for home computer networking.
How expensive is this sort of networking as we compare it to a company network? Well, the cables and RJ-45 adapters are pretty cheap (maybe 20 dollars for a normal sized house with 4 computers). The router itself can be as cheap as 20 dollars (I recommend spending a bit more money on this one to make sure that you will not have problems with it). As far as the network adapters are concerned, all computers built after 2000 come with an on board LAN card so you don’t need to spend any kind of money on those. Totally, I would have to say that it costs roughly 50 dollars to benefit from home computer networking.
You can find that it is even cheaper if all you need is a simple network to play some games with your brother/sister. All you need to purchase in this case is a crossover LAN cable and you are good to go. If one of those computers has two network adapters installed you can even share an internet connection with this type of small home network.
Note that in home computing, a network switch would be the best logical choice, both in terms of cost and effectiveness. if you are going for a wireless network, then I suggest that due importance is given to security. You wouldn’t want un authorized people to log into your network and steal the data from your computer.
Understanding The Functionality Of Network Monitoring
Network monitoring is very essential for companies and small business to have control over the functionality of several workstations. The delivery of a service will be largely based on the condition of the network that handles the operation. With the use of special software applications, companies can monitor the performance of each network from anywhere in the world. With the popularity of cloud based computing or the virtual private server services, the need for a fool proof network is increasing rapidly.
There are many aspects of a network that needs monitoring. Some of them are elaborated as follows.
Monitoring of the performance
Performance of a network should be monitored from time to time, in order to avoid server crashes. Synthetic monitoring, real user monitoring and web logs can be used to understand the performance of the website.
Notifying about network errors
One of the highlights of using monitoring tools is that any hiccups in the network or reports on system failure, will be alerted to the clients through various means of communication. The preloaded solutions that are loaded on to the system will provide scope for self healing of the errors. This will enable the users to experience error free services at all times.
Troubleshooting and resolving the network issue
Through the support of remote connectivity to the servers, monitoring tools can troubleshoot network issues with ease. These tools also automate the fault remediation in order to correct various flaws in the system.
Network mapping
Networking mapping facility allows the client to oversee the network diagram in order to check for networking bottlenecks affecting the server. This will allow the firm to make use of the right tools in order to increase the networks functionality.
Customization
Networking tools can be customized in order to increase the effectiveness of the operations. It is important to make use of the right kind of tools by observing the functionalities of each entity in network management software. By making use of additional plug-ins or add-ons, one can clearly increase the productivity to a great deal.
Network monitoring tools are used to check for any errors in the system using FTP, HTTP, POP3 and SMTP. These will also keep a check on the content that is transferred via the network. Any glitches related to slow response time, downtime or uptime, will be reported to the client with the help of network performance reports that can be utilized to assess the needs of the network.
Data leakage or unnecessary usage of bandwidth can be controlled with the use of these tools. The alerts sent to the central administrating teams will help them to take actions. Any loopholes in the network can be corrected before it gets to the end users. Unauthorized file transfer or data theft can be monitored to a great extent with the help of monitoring tools. Network monitoring tools are a great asset for companies to restrict any unauthorized activity to take place on the network.
Why You Don't Need Your Anti-Virus Program to Scan Your E-Mail
We will explain why we stand by this and why many experts stand by this as well.
First, email is a just a file. A file like any other files. Email whether you read it or not, is stored on your hard drive. Malicious files attached to an email are located on your hard drive. To an anti-virus scanner it does not matter whether the offending file arrived by email, arrived by file-sharing,, or arrived by download. It ...is all the same to it. Any good up-to-date anti-virus will prevent you from opening a malicious worm or virus no matter how it arrived. Until and unless you click the attachment the virus or worm will not execute. And if you're using Outlook Express, and you have kept it updated with the latest patches from http://windowsupdate.microsoft.com/ it will not execute merely by looking at your email.
Our advice is sound. Email scanning might have been useful years ago, but not anymore. We're not sure it ever was. Six or seven years ago one could wander the Internet and open emails rather freely. Viruses were rare and the number of people using anti-virus programs was small. With the Internet Boom of 1999 came an influx of millions of new people using the Internet and millions of new potential targets for those who have nothing better to do than to ruin other people's fun. So worms, Trojans, and viruses became numerous, but still few used good anti-virus protection.
Email Scanning by any anti-virus is not recommended because the harm and delay that scanning can cause don't justify the minimal (if any) benefits to be derived. One of the biggest problem caused by email virus scanners is corrupted Outlook Express DBX (data) files. If these files become corrupted, whatever mail you have stored in them will be unreadable. Email virus scanning is the number one cause of corrupted DBX files; and hence the biggest cause of unrecoverable email. Other problems are minor but they're a nuisance: Aggravating delays in sending or receiving email being among the top nuisances.
Many others do agree with us on shutting off email scanning in your anti-virus program. The following article by Tom Koch, a Microsoft MVP explains it best. Mr. Koch details not only why you should turn off your email scanner but how Outlook Express works, as well as other interesting and little known Outlook Express facts. Here is an excerpt from his excellent article by Tom Koch:
"...When encountering the symptoms of DBX corruption, many people immediately fear that their computer is infected with a virus. As surprising and ironic as it may seem though, the most common cause of DBX corruption is not a virus, but rather anti-virus programs that are configured to scan incoming or outgoing e-mail. Even the most well-known anti-virus programs have exhibited this problem from time to time. To lessen the risk of such corruption you should disable the e-mail scanning module in your anti-virus program. This is usually easy to do by looking at the user-configurable options in the anti-virus program. It is not at all necessary to scan e-mail for viruses to protect your computer.
Now before you dismiss me as mad, let me explain why e-mail scanning is unnecessary. Almost every anti-virus program for Windows installs by default a system scan that runs in the background every time Windows starts. This scan is necessary to protect your computer. If you receive a virus in an e-mail attachment, the virus cannot do anything at all until you actually open the attachment. ..."
See http://www.microsoft.com/windows/IE/community/columns/filecorruption.mspx to read the rest of this article.
The most important thing, and we cannot emphasize this strongly enough, is to use a good, reputable anti-virus program (AVAST and AVG are two good free ones) and keep it updated daily! An anti-virus program which is not updated is worse than none at all. It will return false-positives and ignore real threats. So, above all, keep your anti-virus program up-to-date. And NEVER open an attachment directly from your email. ALWAYS save it to your desktop (or another easily accessible folder) and scan it with your anti-virus program before opening it. Another thing we cannot emphasize enough: Keep your Microsoft Windows current. Either turn on automatic updates or visit http://windowsupdate.microsoft.com/ at least once a week. Finally, we recommend that weekly you visit http://housecall.trendmicro.com/ weekly, just to be sure that no virus or worm has made its way around your anti-virus program. A second opinion never hurts and it's good insurance policy that provides you with the peace of mind that comes with knowing that you're anti-virus has indeed been doing its job.