Archive for the ‘Networks’ Category

Wireless networks use radio waves instead of wires to transmit data between computers. Here’s how:

The Binary Code: 1s and 0s

It’s well known that computers transmit information digitally, using binary code: ones and zeros. This translates well to radio waves, since those 1s and 0s can be represented by different kinds of beeps. These beeps are so fast that they’re outside the hearing range of humans.

Morse Code: Dots And Dashes

It works like Morse code, which is a way to transmit the alphabet over radio waves using dots (short beeps) and dashes (long beeps). Morse code was used manually for years via telegraph to get information from 1 place to another very quickly. More importantly for this example, though, it is a binary system, just as a computer system is.

Wireless networking, then, can be thought of as a Morse code for computers. You plug in a combined radio receiver and transmitter, and the computer is able to send out its equivalent of dots and dashes (bits, in computer-speak) to get your data from here to there.
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Buyer Beware – Ignorance can be a financial waste and a lot of hassals. Before you buy any wireless equipment, you need to be sure about what you’re doing. There’s nothing worse than having everything there and finding that it doesn’t work in your house, or with your computers, or over the distances you need. Here’s a handy checklist of the things that you really ought to do before you go out and spend any of your hard-earned cash on wireless networking equipment.

Interference Checks

While it won’t stop a wireless network from working altogether, interference in its frequency range can slow it down significantly, as well as reducing its range. If something is causing interference, the first thing you’ll know about it is when your connection stops working — unless you know what to look for.

There are two very common causes of wireless interference: wireless phones and microwave ovens. 2.4Ghz, the most common wireless networking frequency, is also a commonly-used wireless phone frequency. It is possible, though, to find phones that use other frequencies. Microwave ovens, on the other hand, operate at around 2.4Ghz by definition. It should be alright to have devices like these in your house, but certainly not in the same room as any computer that you plan to use a wireless connection with.

Wall Construction

Wireless can, in theory, pass through walls and other partitions easily. In practice, though, some walls are more solid than others, which means that they are more likely to block some of the signal. Note that it’s only your interior partitions that matter, not the exterior ones. This does, however, include your floors, if you want the connection to work between levels.

Wireless does well with partitions made from: drywall, plywood, other wood (including doors), glass.

Wireless has trouble with: brick, plaster, cement, metal, stone, double-glazed glass.

Basically, it’s all to do with how porous the materials are — ones that let more of other things through also let more of your wireless signal through.

If you have a wall made of one of the ‘bad’ materials, it’s not the end of the world. It just means that your wireless connection might have a slower speed or a shorter range. You may want to spend more than you otherwise would to get better equipment and overcome this problem.

Decide Your Budget.

You need to stand back, take a look at your needs, and decide how much you’re going to spend. Do you have long distances to cover? Do you want your connection to go through stone walls? Each factor will help you decide how much you should be looking to spend — remember that the more problems you have, the more power you will need. On the other hand, if you live in a small wooden house, you can probably just go for the cheapest thing you can find.
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Home security is an important issue for any person. A person’s home is their castle and they want to feel safe and secure. There are several security measures that can be implemented to ensure security such as alarms but one that ensures peace of mind is a wireless home security camera package.

What’s need in the package is a camera to fit either just outside the front or back door that transmits a wireless signal. The best one to buy would be one that has night vision to ensure you can see everything at night. The second would be a receiver. Some receivers have screens so you can watch what’s going on no matter where you are and others need to be connected to a computer or television to see the transmission.

If connected to a computer or television the live feed from the camera can be directly recorded to a hard drive or a cassette or DVD depending on which is convenient. Several cameras can be implemented to get several signals meaning more coverage of the home and the surrounding area.
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It is a hierarchical representation of all the objects and their attributes available on the network. It enables administrators to manage the network resources, i.e., computers, users, printers, shared folders, etc., in an easy way. The logical structure represented by Active Directory consists of forests, trees, domains, organizational units, and individual objects. This structure is completely independent from the physical structure of the network, and allows administrators to manage domains according to the organizational needs without bothering about the physical network structure.

Following is the description of all logical components of the Active Directory structure:

Forest: A forest is the outermost boundary of an Active Directory structure. It is a group of multiple domain trees that share a common schema but do not form a contiguous namespace. It is created when the first Active Directory-based computer is installed on a network. There is at least one forest on a network. The first domain in a forest is called a root domain. It controls the schema and domain naming for the entire forest. It can be separately removed from the forest. Administrators can create multiple forests and then create trust relationships between specific domains in those forests, depending upon the organizational needs.

Trees: A hierarchical structure of multiple domains organized in the Active Directory forest is referred to as a tree. It consists of a root domain and several child domains. The first domain created in a tree becomes the root domain. Any domain added to the root domain becomes its child, and the root domain becomes its parent. The parent-child hierarchy continues until the terminal node is reached. All domains in a tree share a common schema, which is defined at the forest level. Depending upon the organizational needs, multiple domain trees can be included in a forest.

Domains: A domain is the basic organizational structure of a Windows Server 2003 networking model. It logically organizes the resources on a network and defines a security boundary in Active Directory. The directory may contain more than one domain, and each domain follows its own security policy and trust relationships with other domains. Almost all the organizations having a large network use domain type of networking model to enhance network security and enable administrators to efficiently manage the entire network.
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