Archive for the ‘Computer Networking’ Category
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.”
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.
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An intranet is basically a private web based network. It uses all of the technology of the internet but is safe and protected behind a firewall that keeps unauthorized personnel out. Companies have been using them for years as a method of streamlining their internal communications.
Because a web browser can run on any type of computer, the need to maintain multiple paper copies of documents that are constantly changing can be eliminated. Documents like training manuals, internal phone books, procedure manuals, benefits information, employee handbooks, requisition forms, etc. can be maintained as electronic documents and updated at almost no cost. The savings in paper and other material costs can be significant
But the most powerful aspect of an intranet is its ability to display information in the same format to every computer being used. That allows all of the different software and databases a company uses to be available to all employees without any special equipment or software being installed on their systems.
This universal availability of information is sparking an era of collaboration unlike anything ever seen before. The departmental barriers that exist in many companies are slowing breaking down because now colleagues can share information readily using the company intranet.
Options for implementing an intranet
There are a variety of options for setting up an intranet. They include building your own intranet technology, purchasing and installing third-party software, or purchasing access through an extranet ASP. Here is a quick summary of the advantages and disadvantages of each approach:
1. Building it yourself
Advantages: Complete control of user interface design; ability to customize level of functionality; integration into internal systems, and direct access to user activity.
Disadvantages: High up-front development cost; requires staff expertise in the development of extranets, commitment of internal staff for 6 months to a year for planning, execution, review and implementation; and an ongoing commitment of internal staff for internal and client support, hosting, maintenance and upgrades.
2. Purchasing/installing third-party software
Advantages: Proven track-record of packaged solution; ability to choose functions and to
customize user interface, more rapid implementation compared to building it yourself.
Disadvantages: High up-front purchase cost; commitment of internal staff for customization and implementation; on-going commitment of internal staff for internal and client support, hosting, maintenance and upgrades; and extensive internal and client training
3. Using a Service Provider (ASP)
Advantages: Proven track-record of the application; low cost of entry and predictable cost over time; virtually immediate implementation; no commitment of internal staff for internal support, hosting, or maintenance; and upgrades at no cost by extranet experts, and savings on internal server use.
Disadvantages: Less freedom in user interface design, and fixed functionality.
In the final analysis…
The approach you choose depends on how you work, the technical and financial resources at your disposal, and how rapidly you need to move forward.
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There are more and more individuals opting to work from home than ever before. The advantages to this are many including avoiding the morning and evening rush hours, being able to spend time with your kids and significant other, and doing everything on your own time. Though the pitfalls are many, the one that I will be focusing on in this article is that of setting up a secure wireless network for your home based business. Right now somewhere out there, there is someone with a receiver waiting to pick up on an unsuspecting person’s wireless local area network. Their hope is to garner some sensitive information that may lead to identity theft, and stolen proprietary business information.
Most businesses owners are not technically inclined, though they may be power users, in general security settings is not one of the first things they want to mess around with in their day to day operations. This makes most wireless LANs a great target for information predators.
Here are some general guidelines to follow in setting up your wireless network. Though it may vary from vendor to vendor, the gist is more or less the same:
1. Setup the wireless access/router point via a wired client.
2. Always change the factory setting password to something difficult for someone to guess.
3. Enable 128-bit Wired Equivalency Privacy (WEP) encryption on both your access point and network card. From time to time change the WEP key entries. If your hardware does not support a minimal of 128 bit WEP encryption, then it may be time to replace this dinosaur. WEP is only a minimal security precaution, which is better than none at all.
4. Alter the factory default SSID on the access/router point to a convoluted difficult to guess string. Initiate your computer to connect to this configured SSID by default.
5. Setup your access point not to broadcast the SSID if available.
6. Block off anonymous internet requests and pings.
7. P2P Connections should be disabled.
8. Enable MAC filtering.
9. Enable firewall on the network router/access point with demilitarized zone function disabled. Enable client firewalls for each computer in the network.
10. Update router and access point firmware as updates become available.
11. Make sure the physical router is hidden so that a random person can’t reset the settings.
12. Position the physical router near the middle of the establishment as opposed to near windows to prevent others outside from receiving the signals.
These and other settings will collectively help prevent any unwanted intrusions on your private data.
If you have not decided already,you will soon want to network your two or more computers in your home. You want to be armed to the teach with knowledge of just what it takes to connect your computers to one another.
You first should decide which network is best your you. If your computers are in the same room,the Wireless network should not be considered.The wired by cable network should work just fine.
Computer that may be close to each other but cannot be seen may and have phone jacks close by can easily be networked with the HomePNA Network.While PCs that are far from each other can be connected with the powerline network,assuming wall outlets are nearby.
And when there are computers in different rooms and you want the convenience of moving the systems from room to room,the more expensive Wireless Network is the way to go.After you decide on the type of network that is best for you,knowing what components you’ll need to purchase will be a great help.Let’s take a look at each network and the components needed to get it up and running.
The WIRED ETHERNET NETWORK
If your computers are in the same room,the basic network kit can wire your systems together.Be sure to carefully open any kit or component you purchase and do not damage the box it came in.The purpose for this is to make it easy to return the component if needed.
Basic kits will have instructions and software for the network as seen as two NICs.Better known as Network Interface Cards,these NICs are installed in empty slots in the system unit.The PCI slot is where the card is installed and there are the USB adapters as well.The network will need cabling to connect the computers and the CAT 5 or Category 5 cable is the one to look for.
Ethernet networks come in two speeds,which are 10 and 100mbps or megabits per second.The wired network will also need a Hub or a Switch to direct traffic from each system.If you want fast traffic,and who don’t,you will want to connect a Switch instead of a Hub.If you want all PCs to connect to the Internet,most kits come with Special Bridging Software which links the systems together.
The WIRELESS HOME NETWORK
Wireless networks rely on radio frequency to transmit and receive data.Wireless network equipment will offer you the choice of both wired and wireless connections.
If your computers are in direct line of each other,the IR or Infrared frequency can be used.But most wireless networks now use the Radio Transceiver technology with computers being located just about anywhere.
You will need a Wireless Router to connect each PC to the network.Wireless NIC Cards must be installed in each computer in the network.When you purchase your wireless kit,take note of the indoor range.
As you can see when looking at the wireless Router,you have the option to wire your computers together should something go wrong with any wireless component.Take note of the difference between the wired nic and the wireless nic cards.
The POWERLINE NETWORK
The powerline network uses the electrical wiring in your home to transfer data to and from each computer.Present powerline networks run between 50kbps or Kilobits Per Second and 350kbps.
This network has a drawback in back it will have lots of electrical noise which will cause the network to lose speed.And other PC users can snoop in your computer if they know how.
This network will need a Router for data transfer and nic cards for each system.A Bridge will be needed for access to the internet.These Bridges can be used with your Router.
The PHONELINE NETWORK
The components you will need in the Home Network are close to that of the Wireless network.In most cases,the 10mbps speed network is fast enough for home users.
The computers are connected with a Switch,a gateway,or Router to share Internet access and to send data to each computer through the phone line network.This network is considered the easiest to setup.
Phoneline Network adapters are installed in each PC. The USB or Universal Seriel Bus port connection is the most commonly used adapter for Phoneline networks.To reduce line noise,a Phone Filter may be needed.If you plan to connect a phone and line in one phone jack.you will have to invest in a Line Splitter.Be sure each computer in the network are close to a phone jack.
The Phoneline Network is thought to be less expensive .more dependable and faster when compared with the Powerline network.
In a nutshell,all networks will need some type of adapter inserted in the computer.Each network will need a hub, switch,or router to transfer data.Windows 98,Me,and XP will have the needed software to make everything work together.Adapters and and other hardware will come with device driver software which enables the hardware to talk to the computer.
We have taken a brief look at the hardware needed to network two or more computers.Connecting the hardware was rather simple when we networked our computers using the wireless technology.Learn all you can about PC networking and you will be grateful in having this knowledge should you experience computer problems.
Since we have seen basic network components,its time to see how each component is installed and connected.Then we’re going to see how to move data from one machine to the other and share the internet using broadband with a DSL or a Cable modem.Remember to enjoy learning about your computer by performing as many tasks as you can without causing damage to your system.
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If you already have a wireless network for your computers, you may be very interested in what’s coming next. Would you like it if your PDA, your mobile phone, your mp3 player and almost everything else you connect to your computer could be wireless too? It’s already a reality…
Personal Area Network.
Using wireless networking with your personal gadgets is often called PAN, which stands for Personal Area Network. The idea is that, in the future, we’ll all have laptop computers with their batteries charged and no more need to connect any wires to them at all — you just place your Bluetooth device near the computer, and the computer sees it and can use it straightaway.
Bluetooth has been around and in-use since 1999, and it’s only getting more popular. It was designed to be secure, low cost, and easy to use from day one.
There are two classes of Bluetooth that are in popular use: class 1 and class 2. Class 2 is the most common and cheaper standard, allowing you to use a device that is up to 10 metres (32 feet) away. Class 1 is rarer, but you can still find devices that use it easily enough, and it has ten times the range: 100 metres or 320 feet.
How Does It Work?
Bluetooth is more flexible than 802.11 wireless networking, in exchange for the shorter range. Essentially, a Bluetooth-enabled computer has one Bluetooth receiver installed in it, and this receiver can then be used with up to 7 nearby Bluetooth devices. On the other end, wireless devices do not need to have Bluetooth installed if they support it — it is already integrated.
Like 802.11, Bluetooth works by using radio signals to create bandwidth. It is not, though, the same thing as an old-style wireless mouse or keyboard, which required a receiver to be plugged into one of your computers’ ports, and didn’t have range or stability anywhere near that of Bluetooth.
Many computers now come with built in Bluetooth, especially Apple Macs. If you want to add Bluetooth to a computer that doesn’t come with it pre-installed, you should probably use a USB to Bluetooth adapter, although internal Bluetooth devices to install in your computer are available. If you have a laptop and a spare PCMCIA slot, you can get Bluetooth cards for that too.
What Can You Do With Bluetooth?
Mobile phones with Bluetooth are very popular, and so are PDAs — the instant synchronisation of addresses and calendars to a computer is a useful feature. Other than that, almost anything that would usually use USB can be done using Bluetooth, including digital cameras, mp3 players, printers, and even mice and keyboards. If you take a look through the comprehensive list of Bluetooth ‘profiles’ (kinds of devices that could, in theory, be Bluetooth enabled), it includes cordless phones, faxes, headsets, and even video.
Basically, more than anything, Bluetooth is a replacement for USB: some say that while 802.11 wireless networking is wireless Ethernet, Bluetooth is wireless USB.
Not Just for Computers.
Part of the power of Bluetooth is that it isn’t just used to connect things to computers — it can be used to connect almost anything to anything else, if both things are Bluetooth-enabled and recognise each other.
Mobile phones, in particular, take advantage of this. Hands-free headsets often use Bluetooth to communicate with the phone. Some cars, for example, now have on-board computers that will connect with a Bluetooth phone and allow you to make hands-free calls, regardless of where the phone is in the car (even if you’ve left it in your bag in the trunk!)
On top of that, of course, Bluetooth devices can communicate with each other. This has led to some people sending messages from their Bluetooth PDAs to others in close range — not an especially useful feature, but quite fun. This is called ‘bluejacking’, and the first recorded instance of it was a man who sent a Bluetooth message to another man’s Nokia phone while they were in a bank together. What did the message say? ‘Buy Ericsson’.
Since then, it has become possible to send images by bluejacking, and it is widely believed to be the newest advertising medium — yes, it lets billboards send messages to your phone, a practice known as ‘bluecasting’. Whether you think that’s cool or annoying, of course, is your choice.
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A computer network is a collection of two or more computers with communication between them through a medium. The communication medium can be through radio waves, wires, infrared, optical fibers etc.
Computer network is an integral part of our daily lives, with the most important reason being that of communication. The use of computer networking is to share resources like fax machines, printers, modems, files etc., and its other uses are database server, computer server, email, chat, internet etc. The computer to which the resources are attached is called the server and the other computers that access the resource are called clients. In peer-to-peer computer networks there are no servers.
The sharing of fax machines, printers, and modems amongst many computers and users reduce the operational cost. A database on a computer network is a very important application as it stores and runs many important data and jobs. Emails and chats can be used for instantaneous communication and sending of files on a computer network.
The computer networks are classified, depending upon the size, as Local Area Networks (LAN), Wide Area Networks (WAN), Metropolitan Area Networks (MAN) and Personal Area Networks (PAN). The topology (topology is the way the computer networks and network resources are connected) of the networking can be classified as Bus Network, Ring Network and Star Network.
The networking hardware basically consists of wiring, network cards and a hub. Computer network cards are required so that one computer can understand what the other computer is “talking”. Network cards have a unique MAC address to identify computers on a computer network. Hubs connect all the computers in the network. Hubs can also be used to connect to other hubs to increase the size of the computer network. Two computers can be connected using Ethernet cards or phone lines or power lines for communication, with hardware kits available at roughly a cost of $100.
As the number of computers in an office or a home increases, so do the number of cables, so wireless networking is a viable solution. In wireless networking radio transreceivers or infrared signals are used to communicate between computers and devices. Examples of wireless networking include Wi-fi and Bluetooth technology, though there may be security issues involved in wireless networking. However there definitely is a stronger preference towards wireless networking nowadays among consumers.
Computer networks have added a new dimension to the 21st century. Today the cyber world is much faster and wider than the real world. This has all been made possible due to computer networks. Computer networks have revolutionized business, communication, travel, research, defense, society and almost all human endeavors. The evolution of computer networks has helped the technological revolution take a big leap forward.
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With proliferation of wireless networking and communication equipment it is oh-so-tempting to cut the cord and save a significant sum of money in the process. But is everything that a regular computer networking user needs can be done using just wireless network? Let’s take a look at some pros and contras:
1. One important advantage of having a cabled network is the available bandwidth or simply speed. At the present point in time the speed of connection via a simple and inexpensive CAT5E cable can be 1000Mbit/sec, whereas the best that IEEE802.11g (one of the many flavors of Wi-Fi) can offer is only 54Mbit/sec. It may not seem so significant if you think you are only browsing Internet, and the DSL speed available to you is 1.5Mbit/sec. However, if you need to print via your network connection on a remote printer, you should realize that the print jobs, depending on the amount of graphic data in them, can easily reach dozens and even hundreds megabytes. Since 1Byte=8bit one 100MByte print job will take 15 seconds (and in reality this time can be much longer) to transmit via a Wi-Fi wireless connection, and this time shrinks to mere 1 sec or less on wired 1000MBit/s Ethernet connection. Same principal applies to transferring files, backing up files on other computers in the network etc.
2. It is not possible today and with all probability will not be possible in the future to transmit power needed for your networking device via the wireless link. Unless, of course, you would be willing to be subjected to very high levels of microwave radiation. Thus a device that was marketed to you as “un-tethered” will in fact be very much tethered via the power cord or will have to be re-charged every so often. The power requirements are increasingly important for devices that are expected to be always online, such as phone sets. Therefore it is best to have it connected via a cable that can deliver both power and the communication signal at the same time.
3. Wireless communications are very much proprietary and require whole gamut of conversion equipment to transmit multi-media signals. The same CAT5E cable can without any modification support phone, computer network, balanced line level audio signal, baseband video signal as well as host of other, more specialized, control applications’ signals. With inexpensive adapters called “baluns” the same cable can carry significant number of channels of broadband television or carry a baseband video, such as security camera output, through great distances. All of those applications, except the computer network of course, will require specialized expensive conversion equipment if they needed to be transmitted via a Wi-Fi link.
4. The cost benefit of not running wires around the house is not as simple as issue as it seems. Having installed a wireless network at home you have only eliminated the need to wire for a single application – computer network. A modern home, however, requires all kinds of wiring to run even without regard to computers. The power and phones are obvious examples, as well as thermostats and security systems. Pre-wired speakers are common and most homes today have intercom systems as a desirable option, and those also require extensive wiring. It is very likely that the same contractor running the intercom or security cables is qualified to run computer cables – CAT5E or better. If you are building a home, you should definitely check if computer cabling option is available in your new home, and our advice is to go ahead and purchase it before the walls close. It is going to be a pretty involved and expensive procedure to install the cables later. As an added cost benefit of a wired computer network you will find that all modern computers ship with wired Ethernet network interface card included, and the latest models ship with 1000MBit/sec cards that are essentially free for the computer’s owner.
There are multiple sources of information available on proper planning and design of a residential cabling for voice, data, audio, video and other applications. One of the best sources is the TIA/EIA-570B standard, most resent release of which has been published in 2004. The standard outlines recommended types of the cables, principals of cable distribution in a single- and multi-dwelling units as well as recommended amount of cables to be installed based on the size of the house.
In conclusion, cutting the wire seems like a step forward, some sort of liberation of computer from the bonds of the infrastructure. I would caution the reader, however, to take a more balanced and informed approach before joining the wireless revolution. There are still (and will remain in foreseen future) sound reasons to include properly designed cabling system into the list of your dream home options
Most people are aware that there are continuous security issues with Microsoft’s Windows operating system and other programs. However, what most people do not realize is how easy it is to significantly improve your computer’s security and reduce the likelihood of becoming a victim to ever increasingly sophisticated threats that lurk on the internet. These steps should take less than a couple of hours to complete and should not clean out your wallet.
1) Windows Update – the first crucial step you need to take to make sure that all your Microsoft applications have all the latest product updates installed. These updates or “patches” address security vulnerabilities and other issues. Microsoft usually issues these updates on a monthly cycle. Visit the Microsoft website or switch on automatic updates from the Windows Control panel. Even if your “new” computer is second hand this is still a critical first step. If you buy a used computer with Windows XP make sure Service Pack 2 or SP2 is installed.
2) Strong Passwords - people often overlook this but having well thought through passwords is an important element of your computer security. A strong password should include at least 8 characters with a mixture of text, symbols and numbers. As a minimum you need to make sure the services most at risk have a strong log-in password. These services include your bank, credit card, other financial services like PayPal, your email address and any other services like Ebay which hackers can use to generate profit.
3) Anti Virus Protection – while it is fair to say the threat of the computer virus has receded during the last couple of years they can still inflict serious damage on your computer. Part of the reason why the threat has reduced is because PC manufactures are now more frequently bundling anti virus packages with their new computers. For example last year my new Dell shipped with a 90-day trial of McAfee’s Internet Security Suite. The best bet here is to purchase a security package which includes firewall and anti virus software as a minimum. Top brands include McAfee and Symantec Norton products. However, Microsoft has recently entered the market with their “OneCare” offering which is very aggressively priced.
4) Firewall - if you are using a broadband connection then a firewall is definite requirement to manage the traffic flowing between your computer and the internet. A firewall monitors the inbound internet traffic passing through the ports of your computer. Better products also monitor outbound traffic from your computer to the internet. As per above the best bet here is buy a firewall application as part of a security package which most vendors offer as standard. If a hardware firewall is included as part of your router package then you do not need anything else. A company called Zone Labs offer a great free firewall product called Zone Alarm which should be used as a minimum. Windows XP does now ship with a free firewall but the product does not monitor outbound communication and therefore I believe does not offer adequate protection.
5) Anti Spyware Tool - this software is the last piece in your basic internet security set up. This tool helps combat spyware and adware. There is a good mixture of free and paid versions on offer. Good free software include Microsoft’s Windows Defender, Spybot S&D or Ewido Anti-Malware. Ewido Anti-Malware is frequently recommended in computer help forums. Be careful if you decide to purchase a solution. There are a number of rogue vendors out there which aggressively push products which offer you little value. Stick to trusted names like Webroot’s Spy Sweeper or PC Tool’s Spyware Doctor. These products always come out well on independent tests.
