Specialized Computing Blog

Types of Networks

Just as there are different levels of groups of friends together, there are different levels of networks. The three most common are Personal Area Network (PAN), Local Area Network (LAN) and Wide Area Network (WAN). Let’s take a look at what makes these networks different and what types of hardware they commonly use.

Personal Area Network (PAN)

PANs are relatively short-ranged networks, usually intended for communicating between a couple of devices. This would be like you and your friends getting together and networking over lunch. PANs are usually found in homes, between a couple of computers and possibly a printer and scanner through the use of a router.

Local Area Network (LAN)

The local scene is an example of a LAN where many people can come together. This location is big enough for everyone, but they do not have to be in the same place. LANs are usually found in office spaces, where the server room may be in one area and the physical computers in another area. These types of networks generally use network interface cards, which are adapters installed on a computer with the responsibility of connecting that computer to the network.

Wide Area Network (WAN)

The last of the three types of networks is the WAN. This network would be similar to instant messaging with your friends or chatting with them via Skype. This type of network uses switches and hubs to help control the flow of data and communications over a long distance. Companies who have national or international conglomerates uses WAN’s to keep everyone in the company connected.

Going In-Depth With Computer Networking

It is simple to think about networking if you can imagine physical interactions between people. Computer networks work the same way. If you would like a more in-depth understanding of computer networking, seek out local classes or go sit with your IT department during your lunch. The art of computer networking truly is a fun world.

Next week, we’ll talk about Hardware and Software in general, and how it all works together to create a “personal computer”…

Networking

When you get together with your friends, you are networking. When you go to a party and meet new people, you are networking. When you use online media to communicate with others, you are networking. So it stands to reason computer networks work along the same guidelines. Computer networks relate to a group of computers, which are linked together, communicating, in order to share information and available resources.

How Networking Works

Networks can consist of a multitude of machines, down to just a few. These may include laptop computers, desktop computers and a server, but also may encompass printers, scanners, data storage devices, fax machines and just about any other communication equipment you could think of. Of course, whether you are meeting with people in person, or online, there has to be someone available to help guide the conversation and keep everything on track. In the computer world of networking, this is known as the “data center,” usually located in the server room.

The data center is the headquarters of the networking team. All of the equipment necessary to maintain smooth operation of the network is kept inside an air-conditioned room. It is imperative to keep this equipment in top shape. If equipment starts to deteriorate, something could go wrong and there would be a negative effect on the entire network. If a connection comes un-soldered, the whole file storage department might be lost. If a cobweb shorts out the data communications side of the house, no transmissions will be able to get in or out of the network.

Of course, not everything has to be physical to go wrong. Since all of the devices are interconnected within this network, if something happens with one computer, it could damage the entire network. Think about the Christmas tree lights; when one goes out, the whole string goes out. If one computer is infected with a serious virus, the network may actually assist in spreading the virus between computers. Of course that is the worst case scenario. The first computer with the virus may be able to terminate it before spreading throughout the network, only sustaining damage to the communications portion of the network.

Next week, we’ll look at the different types of computer networks…

Virtualization

People were practicing virtualization long before computers. Architects were drawing buildings, contractors were making detailed sketches and engineers were developing their systems; all with a pen and paper. Today, we can do far more than the simple 2-D drawings of the past. Virtualization allows us to build complete cities, in high detail 3-D imagery, then with a click of the mouse, decimate and rebuild in a completely different manner. Not to mention, virtualization is starting to become a mega-trend in the health industry. Doctors and health care professionals are able to create life-like replicas of situations and see the possible side effects and outcomes of different procedures.

In the computer world, virtualization has the same connotation, but with different aspects. For instance, instead of mapping out cities or hearts, Information Technology workers are creating virtual workstations, servers, operating systems and network resources.

Computer virtualization allows you to have a network of computers, running two or more completely different environments, on a single piece of hardware. For example, Apple can run their standard Operating System (OS), while having the ability to mimic a Dell PC and run the Windows OS. Virtualization splits computers from their applications, by creating a virtual machine (VM), which gives it the ability to act as a host to a larger number of systems.

There are a wide variety of virtual specialties, including Operating Systems, network, server, hardware and even storage. Let’s take a look at what each discipline entails.

Hardware Virtualization

You probably know a little about virtualization if you have ever decided to partition your hard drive into logical divisions, creating basically two hard drives in one. This is hardware virtualization. This discipline is tasked with partitioning the computer’s memory into separate and isolated virtual machines to simulate multiple machines within one physical computer.

Operating System Virtualization

This type of virtualization allows the computer to take a step back and act as a simple display for different operating systems; much like Apple started doing a few years ago. This uses software to allow a piece of hardware, such as a computer, to display different operating system windows at the same time because it is not tied to either of the two systems.

Network Virtualization

Network virtualization combines all of the available resources in a network by splitting up the available bandwidth into channels. Each of these channels is completely independent of each other and can be devoted, or reassigned, to a particular server or individual in real time. This allows the complex network to be separated into manageable parts that can be worked on or devoted to different tasks without affecting the other ones.

Storage Virtualization

This type of virtualization pools physical storage locations from multiple devices within a network and allows it to act as a single storage device. If you have a single drive to save all of your documents where you work, this would be an example of storage virtualization.

Server Virtualization

Bandwidth is a large issue for companies; a hot commodity within the IT world of corporations. Server virtualization hides the identity of each user from the physical server and keeps users from having to understand and manage the ever-daunting task of server resources. It also increases the ability to share resources and gives the company the ability to expand in the future.

Conclusion

While we have been working with virtualization before the digital age, the technology we have access to now changes the entire game. These categories of virtualization can actually lead the way into autonomic computing; where IT teams will be able to manage the systems based on perceived activity and resources used, allowing clients to only pay as resources are needed.

Next week, we’ll look more in-depth at computer networking…

How Does This All Fit Together?

Let’s put this all together. Here is an example of how a server works and helps organize the jobs sent to it from a network experience.

For instance, in an office of 100 people, there may be multiple printers that have different printing capabilities, various file storage options, different levels of staff and different roles of varying importance. Let’s say that 15 people send a job or task to the server within a few minutes of each other. The server analyzes each job based on information such as IP address, proximity to the server and order of importance in processes. The server determines first, who has priority ranking – is the job coming from the CEO, the accounting department or sales? Then the server determines what resources the job requires – color printing or black and white? The server then can choose to send the CEO’s print job to high quality printer; the accounting department’s spreadsheet to the regular black and white printer; and, the sales department’s presentation to the copier.

Think about all the steps that are involved in any business small or large. The server organizes all the computer related tasks for the most efficient use of resources and speed. Depending on the size of the business, there may be many servers both on and off site. When a server goes down, all the technology related tasks become disorganized and things slow down or don’t function at all. The next time you are at the store or call your bank and they say “Sorry, we can’t help you, the server is down” you will now know that it is more than a convenient, technology based excuse to not do what you want them to.

Next week, we’ll look at what’s known as “Virtualization”…

Servers

How many times have you heard the term “the server is down” or “the server failed”? Most likely many! In today’s technologically savvy world, we have all become familiar with the term “server” but few people outside the Information Technology world truly know what it means or can describe accurately describe it. Servers are everywhere today from the grocery store, to our workplace to our schools, it’s time to be in the know!

What is a Server?

A computer server is a Central Processing Unit (CPU) on a network that manages the resources available to the computers attached to that same network. There are different types of servers; some can multitask between different sets of data and others can be dedicated to a single type of task, such as printing or file storage. Servers can be both on-site or off-site.

A computer server takes the task you are trying to accomplish and sends up the request to be processed. Computer servers have to put tasks into order of importance and many times, this is a first-come-first-serve basis. However, tasks can also be ordered by type of job, company department or individual positions within a company.

When a computer related job (task) is required, the server is the first line of contact. A job may be document printing, copying, faxing, file storage, data processing and more. It is the server that assigns each job to the most appropriate resource, gives it a priority ranking and places it in queue. This queue is designed to order computers into a tiered level of importance. If there were no organization, the server would get overloaded trying to process all of the requests at the same time and the result would be an inefficient, slow or broken system.

How does the server know what which jobs to process first? The server assigns the jobs based on a set of rules that the administrator of the server has set up. For instance, in many companies, priority may be given to particular staff or departments. Any jobs coming from the CEO’s office could be assigned top priority and be processed before any others. Servers also assign jobs based on available resources. For instance, it will send the color print jobs to the color printer, a fax to a fax machine and copies to a copier.

Finally, servers also organize tasks based on efficiency. A server can recognize when one resource is being utilized and send a job to another resource to increase overall efficiency. A good example of this is a large print job. If one printer has been assigned a large (100 pages or more) print job and a small 2 page job comes through, rather than assigning it to the printer printing the large job and make the requestor wait, the server will assign it to a free printer.

Next week, we’ll look at how this all fits together…