Archive for the ‘Networks’ Category:
Written on September 1st, 2009 by adminno shouts
Wireless networks work using radio waves instead of wires to transmit data between computers. That`s the simple version. If you`re curious to know what`s going on in more detail, then it`s all explained in this article.
Ones and Zeros.
I`m sure you know that computers transmit data digitally, using binary: ones and zeros. This is a way of communicating that translates very well to radio waves, since the computer can transmit ones and zeros as different kinds of beep. These beeps are so fast that they`re outside a human`s hearing range — radio waves that you can`t hear are, in fact, all around you all the time. That doesn`t stop a computer from using them, though.
Morse Code.
The way it works is a lot like Morse code. You probably already know that Morse code is a way of representing the alphabet so that it can be transmitted over radio using a dot (short beep) and a dash (long dash). It was used manually for years, and became a great way of getting information from one place to another with the invention of the telegraph. More importantly for this example, though, it is a binary system, just like a computer`s ones and zeros.
You might think of wireless networking, then, as being like Morse code for computers. You plug a combined radio receiver and transmitter in, and the computer is able to send out its equivalent of dots and dashes (bits, in computer-speak) to get your data from one place to another.
All About Frequencies.
You might wonder, though, how the computer could possibly transmit enough bits to send and receive data at the speed it does. After all, there must be a limit on how much can be sent in a second before it just becomes useless nonsense, right? Well, yes, but the key to wireless networking is that it gets around this problem.
First of all, wireless transmissions are sent at very high frequencies, meaning that more data can be sent per second. Most wireless connections use a frequency of 2.4 gigahertz (2.4 billion cycles per second) — a similar frequency to mobile phones and microwave ovens. As you might know, though, a frequency this high means that the wavelength must be very short, which is why wireless networking only works over a limited area.
How Do Wireless Networks Work?
First of all, wireless transmissions are sent at very high frequencies, meaning that more data can be sent per second. Most wireless connections use a frequency of 2.4 gigahertz (2.4 billion cycles per second) — a similar frequency to mobile phones and microwave ovens. As you might know, though, a frequency this high means that the wavelength must be very short, which is why wireless networking only works over a limited area.
In addition, wireless networks make use of a technique known as `frequency hopping`. They use dozens of frequencies in the range they are given, and constantly switch between them. This makes wireless networks more immune to interference from other radio signals than they would be if they only transmitted on one frequency.
Access Points.
The final step is when it comes to all the computers on a network sharing Internet access. This is done using a special piece of wireless equipment called an access point. Access points are more expensive than wireless cards for one computer, as they contain radios that are capable of talking to around 100 computers at the same time, and sharing out access to the Internet between them. Dedicated access points are only really essential for larger networks, though — if you only have a few computers, it is possible to use one of them as the access point, or you could just get a wireless router.
They Understand Each Other.
That`s all well and good, then, but how does wireless equipment made by entirely different companies manage to work together when this is all so complicated? Well, the answer is that there are standards that all wireless devices follow. These standards are technically called the 802.11 standards, and are set by the IEEE (Institute of Electrical and Electronics Engineers). It is thanks to people sticking to their standards that wireless networking is so easy and cheap to use today.
You Don`t Need to Worry.
If all this talk of frequencies has you a little worried, you don`t need to be — wireless networking hardware and software handles all of this automatically, without you needing to do a thing. Don`t think that you`re going to have to tell one wireless device what frequency another is using, because it`s just not going to happen, alright? Wireless networking, for all its complicated workings, is really far more simple to use than you`d ever expect.
Written on September 1st, 2009 by adminno shouts
It is deniable that our works and lives are more convenient and easier when using wireless. We can work anywhere and that is why wireless networks are becoming so popular. Especially if you have broadband Internet access, a wireless router can give you instant communication with the world.
Imagine you are sitting by the pool and enjoying chatting through the Internet. Or lounging in the Jacuzzi listening to your MP3 collection is appealing to us all. Unfortunately, many, or even most, wireless units don`t come with security features already functioning. This may not seem like a big issue to someone who is simply setting up a home network, but there are a number of potential problems you should consider.
Identity theft seems to be the most serious problem. If your network is unsecured, the personal data on your wireless electronic equipment is also unsecured. The order you just placed for a book at Amazon may have given your contact and payment information to an unscrupulous hacker! Nearly every town in which “WiFi” is common will have “War Drivers” and “War Chalkers” at work. These are people who walk or drive around town with wireless equipment, searching for unsecured networks. The “Chalkers” then live up their name, marking curbs and other public items with chalk so that others can more easily find and exploit your network.
In fact, not all “War Drivers” are hackers, of course. Many just want to use your network for free, but the risk is high if you don`t learn how to protect yourself. You can usually find quite a bit of free information as to how to secure your network at the website of your router`s manufacturer, or by doing a search in a search engine for a phrase like “secure home wireless.”
Protect Your Network From Identity Theft Now!
In addition, there are also your neighbors who may find your network by accident and enjoy nosing into your activities and using your Internet access at will, slowing down your network speed in the process.
Even many businesses use cheap, home-use quality equipment for their company networks. With the poor security often found on small business networks, anyone with a basic knowledge of wireless can access sensitive company and customer data.
It is highly recommended that you hire service companies to secure your network for you, or else you will have to bear with a risk of being exploited. A search of your local yellow pages or an inquiry at your neighborhood computer store should yield professional help and get your private data private again.
Written on September 1st, 2009 by adminno shouts
Cabling of data and voice systems is often ignored by many companies until the last minute just before relocation or new building takes place. Many information systems professionals view it as a low priority or something that just takes away from their budget for real network components such as servers or software. However having a state of the art easy to manage cabling system is just as important as good reliable servers on a network. Cabling is the backbone of any computer network; it ties all the components of the network together therefore it should receive as much careful consideration as any other network component.
Mistake number one – Blindly choosing the lowest bidder
This is the most common mistake made when installing voice and data network cabling. Often the lowest bidder is the contractor who is the smallest, has the least experience or the one that made a mistake on their bid. Prior to making this decision you should know your contractor. Find out how long they have been in business, visit some of the large installations they have done and by all means go visit their offices and warehouse. A site visit to their office will tell you most of what you need to know about an organization. Make sure your contractor has completed jobs of similar scope and size.
Mistake number two – Choosing the manufactures product that will be installed
Many companies have tried to standardize on a particular manufacture of cabling system. Some of the larger manufactures are Belden, Comscope, Ortronics, AMP and Leviton. You can’t go wrong with any of these big names. However IT managers and corporate executives get hung up on trying to standardize because they believe it will make things easier for the IT staff. The reality of the situation is that if you choose any of the larger names the only components that might not be interchangeable are the faceplates. Of course there are performance criteria as well and they all claim to be the best. Do your own research and choose a manufacture that you feel has a strong company that will be there to stand behind their product should you even need to make a warranty claim
Mistake number three – Paying too much for the latest cabling technologies
The fact is that today’s network components and network components of the future cannot exceed the specifications of Cat 5E and Cat 6 cabling components. Combine this with the fact that the average company moves every 3 to 4 years. You will find it hard to benefit from future proofing a building you don’t occupy. Look at you current infrastructure, what equipment or applications do you plan to add or upgrade? Is Gigabit or 10 Gigabit Ethernet an option for you in the near future?
Mistake number four – Not using universal wiring
The EIA/TIA and BICSI both recommend a universal wiring platform for your Communications Infrastructure. In the old days the average install would consist of a single voice grade cable for the phone system and a single data grade cable (Cat 3, Cat5, Cat5E or Cat 6) for their computers. This of course dedicates the usability of these cables to one system type. This is further exacerbated by the termination method used. Voice cables were traditionally terminated on 66 style blocks (66m1-50), which are not user friendly and require a special tool and cross connect wire to make changes. Telephony companies have made a killing for years just performing MAC work (Moves, Adds and Changes) because a customer was unable or unwilling to brave the telephone closet and perform the MAC work themselves.
Six Largest Mistakes Made when Hiring a Cabling Contractor
The EIA/TIA and BICSI both recommend a universal wiring platform for your Communications Infrastructure. In the old days the average install would consist of a single voice grade cable for the phone system and a single data grade cable (Cat 3, Cat5, Cat5E or Cat 6) for their computers. This of course dedicates the usability of these cables to one system type. This is further exacerbated by the termination method used. Voice cables were traditionally terminated on 66 style blocks (66m1-50), which are not user friendly and require a special tool and cross connect wire to make changes. Telephony companies have made a killing for years just performing MAC work (Moves, Adds and Changes) because a customer was unable or unwilling to brave the telephone closet and perform the MAC work themselves.
The practice of using a true universal wiring platform is now the standard for all reputable cabling contractors. A Universal Wiring Platform is made up of all data grade components that are downward compatible for all voice applications. A common installation would consist of 3 Category 5E or Category 6 cables all terminated on a 110 type Patch Panel. At the wall plate all cable would be terminated on the matching grade of 8 position modular jack (incorrectly know as an RJ-45). This design not only allows for maximum flexibility were the customer could have 3 computers or 3 phones or 2 computer and 1 phone or any configuration that works for their application. The point is that now the customer is in complete control of their cabling infrastructure and does not need to pay a contractor to come out every time they move an office. In the long run this will also save you money on the overall cabling system as it will shift and flex to meet your needs without having to bring in your cabling contractor. Remember, having the contractor in after construction has completed will involve them pulling out ceiling tiles and standing on desks while you are trying to do business. The elimination of the disruption alone makes it worth while.
Mistake number five – No CAD pre installation and post installation CAD drawings.
Most customers really have no idea what their cabling platform will look like when they sign the paperwork. They rely on their contractor to “just do the right thing”. Do not make this mistake, if you don’t understand how your infrastructure will work or what it should look like, don’t sign. Your contractor should have the ability to take your building blue print and overlay his cabling plan on top of your electrical plans. This will give you a visual representation of what you are paying for and allow you to ask questions. Likewise, after the job is complete you should receive what is called an “As Built Drawing” showing all of your communications outlets with a standards based numbering system. Some contractor will even provide a scale elevation plan showing were your patch panels are and how much room you have left in each rack for growth and or other equipment. This should be provided to you both hard copy and in AutoCAD format for your architect to incorporate into your final building As Builts.
Mistake number six – Not getting a design before the job starts.
This seems to be all over the board, some people have no design plan what so ever. Some will pay $10,000 for an engineering firm to write a specification were they charge by the pound for the spec. Don’t be fooled that a large spec is a good spec. Often a specification filed with time consuming exercises for the bidding contractor and unnecessary pricing breakouts will only prevent good contractors from bidding on your project. What you want is a spec that clearly defines your realistic requirements, requires basic qualification with references and does it as quickly and simply as possible. Do not try to write a spec that will cover every contingency, you will drive your contractor away and you will only confuse the process more. Once you have selected your contractor based on an apple s to apple comparison, you can always and should always sit down to discuss the project and other options that they recommend. One more thing, always, always have the contractor provide you with a parts list with quantities, not individual prices, just quantities. This will help you weed out the contractors that did their homework when you start to compare their list of parts.
Mistake number six – No cable management
All cabling systems will look organized before they are used, that’s easy. Show me that cabling system after 6 months and I will tell you if the proper wire management was used. “Used” being the key word here. Remember, you can have the best wiring management in the world, if you don’t strictly enforce its use with your IT Staff, you will have a mess. That said, your contractor must provide you with a good design. My recommendation is, listen to your contractor, they know more than you do about this. Then, go visit some of the sites that are done the way they recommend. See how they look after being used a few months. Ask the customer how easy it is to keep organized. Don’t underestimate the value of this step. If your patch panels are a mess and you can’t effect changes in a rapid and orderly fashion then you would have been better off paying your contractor to do the MAC work for you.
Older Posts »