Local Area Networks also called LANs have been a major player in industrialization of computers. In the past 20 or so years the worlds industry has be invaded with new computer technology. It has made such an impact on the way we do business that it has become essential with an ever-growing need for improvement. LANs give an employer the ability to share information between computers with a simple relatively inexpensive system of network cards and software. It also lets the user or users share hardware such as Printers and scanners. The speed of access between the computers is lighting fast because the data has a short distance to cover. In most cases a LAN only occupies one or a group of buildings located next to each other. For larger area need there are several other types of networks such as the Internet.
LANs systems can be defined and connected in many different ways. This is the reason for the standardization for every one can have a common ground to start from. “The LANs described Herein are distinguished from other types of data networks in that they are optimized for a moderate size geographic area such as a single office building, warehouse, or a campus. The IEEE 802 LAN is a shared medium peer-to-peer communications network that broadcasts information for all stations to receive. As a consequence, it does not inherently provide privacy. The LAN enables stations to communicate directly using a common physical medium on a point-to-point basis without any intermediate switching node being required. There is always need for an access sublayer in order to arbitrate to access to the shared medium. The network is generally owned, used, and operated by a single organization. This is in contrast to Wide Area Networks (WANs) that interconnect communication facilities in different parts of a country or are used as a public utility. These LANs are also different from networks, such as backplane buses, that are optimized for the interconnection of devices on a desk top or components within a single piece of equipment.”(IEEE 802 Standard 1990) That is the standard definition for LANs by Institute of Electrical and Electronics Engineer committee 802. They are the committee used to set the standard in workmanship and operations for technicians that set-up and perform maintenance on LANs systems. And through all the technical words what they are trying to say is a LAN is a small area network that distributes information among computer in a small work environment unlike WANs that distribute information across global areas. “It is usually the case that LAN is owned by the same organization that owns the attached devices. For WANs, this is less often the case, or at least a significant fraction of the network assets are not owned. This has two implications. First, care must be taken in the choice of LAN, since there may be substantial capital investment (compared to dial-up or leased charges for wide-area networks) for both purchase and maintenance. Second, the network management responsibility for a local network falls solely on the user”. (Local and metropolitan area networks 1997).
The question now is you have a standard and you have a connection now how do you manage the system to run flawlessly?” Networks use protocols, or rules, to exchange information though a single shared connection. These protocols prevent collisions of data caused by simultaneous transmission between two or more computers. Computers on most LANs use protocols known as Ethernet or Token Ring. An Ethernet-linked computer checks if a shared connection is used. If not, the computer transmits data. Since computer can sense an idle connection and send data at the same time, transmitting computers continue to monitor their shared connection and stop transmitting if a collision occurs. Token Ring protocols pass a special message called a token through the network. A computer that receives the token is given permission to send a packet of information or, if the computer has no packet to send, it passed the token to the next computer.”(Local Area Network Microsoft 2000) I know that it is complicated to understand, but for the actual user the software takes care of most all of the management for you.
There are seven things that a LANs can do that you cannot with ease do with non-networked stand-alone systems. First sharing files “ A LAN enables many user to share a single copy of a file stored on a central file server computer.”(Introduction to Networking 1992) Transferring files “A LAN enables you to copy files from machine to machine without having to exchange floppy disks.”(Understanding Data Communications 1993) Access information and files “A LAN enables anyone to run the accounting software, for example, or other application software from any of the workstations”(Introduction to Networking 1992) Share applications “A LAN enables two people to use the same copy of the Microsoft Word word processing program simultaneously”(Introduction to Networking 1992) Simultaneously key data into an application. Printer sharing and electronic mail with in the system.
In conclusion the LAN has become essential in the modern work environment. The ever-growing need for advancement has become a very profitable industry in its self and it will continue to grow for a long time to come. For now we are barely skimming the possibilities and uses for this new networking technology.
Tuesday, February 28, 2006
Monday, February 27, 2006
Cabling Your Home for Computer Network - Still a Requirement?
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.
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.
Sunday, February 19, 2006
An Overview Of Computer Networks
My second degree, or should I say my second go through inside the education system was in networking. I'm a certified Novell and Microsoft engineer, not that I'm all that excited about the fact. Networking is actually pretty mindless work once you learn it. It's pretty much do it by the numbers based on what the customer wants. After you hook everything up the software installation is pretty straight forward. My 16 year old daughter could do it or as GEICO would say, a caveman could do it.
In this article I'm just going to cover the basics of what a network is and the types of networks. I'll go into more detail in later articles.
A network is simply a means for computers to speak to each other, or communicate with each other. With a network, computers can receive emails from each other, send files to each other, instant message each other and a variety of other things. This is something that we take for granted today but there was a time when networks were not so sophisticated and not all that efficient either.
There are basically two types of networks.
The simplest network is a LAN or Local Area Network. This is where all the computers in the network are located in one place such as an office building. Within this type of network you have 2 ways to connect.
The simplest way is peer to peer. This is where 2 or more computers are hooked up directly to each other. In other words if you have 5 computers you would have computer 1 hooked into computer 2 which would be hooked into computer 3 and so on. In this type of connection each computer is dependent on the other. So if computer 3 would go down then computers 1 and 2 would not be able to communicate or exchange information with computers 4 and 5 and visa versa. That is the main problem with a peer to peer network. Also in peer to peer networks the write process between computers leads to data corruption problems. This is not something they teach you in school but something you learn from experience.
The more common type of LAN connection is client server. This is where all the computers in the network are connected to each other via a central computer. This kind of connection does require more work in set up but is more efficient, carries data better and if one computer goes down the others aren't affected. However, should the server go down then all the computers on the network would be affected as far as their ability to get information from the other computers and the server itself. They, however, would still be able to do work locally on their own such as with a word processing program, unless the word processing program was located on the server. Then it would not be available. Usually, however, most applications are installed on each computer. What is most commonly lost when a server goes down is the ability to retrieve data that is common to everyone in the network, say an in house database of all employees.
The second type of network is a WAN or wide area network. This is where several LAN networks or even single computers are connected to a much larger network. A perfect example of a WAN is the Internet. This is where users from all over the world can interact with each other through email, chat rooms and instant messaging. WANs are enormous to say the least and are very intricate in their design, requiring hubs from all over the world to stay connected. One hub goes down and it can affect connections for millions of people though there are protocols instituted to reroute connections if a hub does go down.
In this article I'm just going to cover the basics of what a network is and the types of networks. I'll go into more detail in later articles.
A network is simply a means for computers to speak to each other, or communicate with each other. With a network, computers can receive emails from each other, send files to each other, instant message each other and a variety of other things. This is something that we take for granted today but there was a time when networks were not so sophisticated and not all that efficient either.
There are basically two types of networks.
The simplest network is a LAN or Local Area Network. This is where all the computers in the network are located in one place such as an office building. Within this type of network you have 2 ways to connect.
The simplest way is peer to peer. This is where 2 or more computers are hooked up directly to each other. In other words if you have 5 computers you would have computer 1 hooked into computer 2 which would be hooked into computer 3 and so on. In this type of connection each computer is dependent on the other. So if computer 3 would go down then computers 1 and 2 would not be able to communicate or exchange information with computers 4 and 5 and visa versa. That is the main problem with a peer to peer network. Also in peer to peer networks the write process between computers leads to data corruption problems. This is not something they teach you in school but something you learn from experience.
The more common type of LAN connection is client server. This is where all the computers in the network are connected to each other via a central computer. This kind of connection does require more work in set up but is more efficient, carries data better and if one computer goes down the others aren't affected. However, should the server go down then all the computers on the network would be affected as far as their ability to get information from the other computers and the server itself. They, however, would still be able to do work locally on their own such as with a word processing program, unless the word processing program was located on the server. Then it would not be available. Usually, however, most applications are installed on each computer. What is most commonly lost when a server goes down is the ability to retrieve data that is common to everyone in the network, say an in house database of all employees.
The second type of network is a WAN or wide area network. This is where several LAN networks or even single computers are connected to a much larger network. A perfect example of a WAN is the Internet. This is where users from all over the world can interact with each other through email, chat rooms and instant messaging. WANs are enormous to say the least and are very intricate in their design, requiring hubs from all over the world to stay connected. One hub goes down and it can affect connections for millions of people though there are protocols instituted to reroute connections if a hub does go down.
Wednesday, February 15, 2006
Get the Highest Speed Out of Your Wireless Computer Network
When it comes to a wireless standard, the first thing we all look at is how fast will this baby run! And you know the trade-offs, you can spend a lot of money to get the fastest thing running, or you can back off a little and save a lot.
The good thing about wireless networks is that the price difference between wireless standards is almost gone. There are some things that could add up, but I will explain the difference and why you might want to go that route or not.
Now, let's get to the different wireless standards you can choose from.
1. 802.11b - 11Mbit at 2.GHz
2. 802.11a - 54Mbit as 5.0GHz
3. 802.11g - 54Mbit at 2.4GHz
4. Hybrid Systems
When you get ready to purchase your equipment, you will see a lot of systems saying that they are faster than these standards listed above. Most will say 108Mbit per second, some 125Mbit per second and a few even higher. To operate at these speeds usually requires you to only use their network cards to access their access points, some of them require a specific card from them to get that speed. If any other card connects, then they will drop back to the standard speed and you lose the extra speed you probably paid extra to get.
What Should You Get
I was purchasing equipment for a completely new wireless setup. We only had one older wireless computer and I replaced the card in it with a new one. I did purchase a system that advertised the 108Mbit speeds since I knew who was going to connect to it.
If you are building a new network setup, I suggest you purchase a system that will run faster than the standard, but only if you know who is connecting. If not, then get a system that runs on the 802.11g standard. The price is about the same as 802.11b but runs 5 times faster.
The good thing about wireless networks is that the price difference between wireless standards is almost gone. There are some things that could add up, but I will explain the difference and why you might want to go that route or not.
Now, let's get to the different wireless standards you can choose from.
1. 802.11b - 11Mbit at 2.GHz
2. 802.11a - 54Mbit as 5.0GHz
3. 802.11g - 54Mbit at 2.4GHz
4. Hybrid Systems
When you get ready to purchase your equipment, you will see a lot of systems saying that they are faster than these standards listed above. Most will say 108Mbit per second, some 125Mbit per second and a few even higher. To operate at these speeds usually requires you to only use their network cards to access their access points, some of them require a specific card from them to get that speed. If any other card connects, then they will drop back to the standard speed and you lose the extra speed you probably paid extra to get.
What Should You Get
I was purchasing equipment for a completely new wireless setup. We only had one older wireless computer and I replaced the card in it with a new one. I did purchase a system that advertised the 108Mbit speeds since I knew who was going to connect to it.
If you are building a new network setup, I suggest you purchase a system that will run faster than the standard, but only if you know who is connecting. If not, then get a system that runs on the 802.11g standard. The price is about the same as 802.11b but runs 5 times faster.
Wednesday, February 08, 2006
Computer Network Management
Today it is almost inconceivable for a business not to have computers, whether it is a construction company or a high technology firm. When a business has more than one computer, they are almost always connected together in a local area network. These networks may be more or less advanced and therefore more or less costly.
Companies invest so much (in terms of both money and time) in a local area networks because there are many advantages that a local area network brings to a business and how it is administered.
Some businesses use a local area network in such a way they are highly dependent on it always working. If the company's network fails, then you may see all the employees chatting away in the corridors because they can't do their work. This means big losses for the company and causes stresses on the employees. All companies must consider their local area networks a vital asset and downtime must be avoided. This imposes huge demands on the network staff to keep such networks running almost 100% of the time.
The advantages of Computer Network Management
One of the main advantages of installing and maintaining LANs is the opportunity they create for better communication and cooperation between employees and customers.
Security considerations: Local Area Network security can be both a help and hindrance. Comprehensive security is beneficial because it provides a central and safe strategy for data access and disaster recovery. All information is protected by the design and implementation of the network security solution. On the other hand, interconnecting computers in local area networks creates a security risk, since doing so makes it technically possible for intruders to access many machines on the network at once.
Cost considerations: Installing a local area network is a relatively expensive project. Servers, cabling, switches, routers and software can all be expensive and should never be purchased without expert advice. Keeping the network operating and secure also requires a lot of resources and can be costly.
Surprisingly, a local area network can bring a number of cost savings. Sharing resources avoids the need to purchase equipment for each individual. Even more important is the security that a local area network can provide. Data loss could cost a business a great deal of money and in some cases, cause the business to shutdown altogether. Computer Network Management should require a consistent routine for data backups with regular checkups of data quality - a practice that will save a company huge sums in the event of a mishap.
Computer Network Management: preliminary analysis phases
The first phase of computer network management is to determine the source of the problem (a preliminary study that looks into several options of differing scope may be useful here) and defining it in a specification of requirements. Examples of what should be evaluated are different network operating systems, mail systems, and other applications. The choice of hardware components should also be evaluated. This phase is generally aimed at establishing what the system should do, not how it should do it.
Computer Network Management: design phase
The purpose of design phase is to determine how the requirements of the specification are to be met. The current approach to large, complex projects is to break them down into smaller, more manageable subprojects.
Computer Network Management: implementation phase
This phase involves the physical installation of the local area network. Cables are run, software is installed, and computers and other hardware are put in place.
Computer Network Management: integration and system testing phase
In this phase, commissioning of the network begins, and routines are adapted to users and the operating personnel. The system must be tested, both to ensure that the network meets the requirements set out in the specification and that it is stable enough to perform the central function it has in the organization.
Computer Network Management: operation and maintenance
Local area networks have complex operating routines. This is because there may be serious consequences when faults occur or unauthorized persons gain access to the system. Many companies have employees devoted solely to take care of running and maintaining computer networks. These system administrators may deal with network issues such as performance, reliability and security of both hardware and software.
Companies invest so much (in terms of both money and time) in a local area networks because there are many advantages that a local area network brings to a business and how it is administered.
Some businesses use a local area network in such a way they are highly dependent on it always working. If the company's network fails, then you may see all the employees chatting away in the corridors because they can't do their work. This means big losses for the company and causes stresses on the employees. All companies must consider their local area networks a vital asset and downtime must be avoided. This imposes huge demands on the network staff to keep such networks running almost 100% of the time.
The advantages of Computer Network Management
One of the main advantages of installing and maintaining LANs is the opportunity they create for better communication and cooperation between employees and customers.
Security considerations: Local Area Network security can be both a help and hindrance. Comprehensive security is beneficial because it provides a central and safe strategy for data access and disaster recovery. All information is protected by the design and implementation of the network security solution. On the other hand, interconnecting computers in local area networks creates a security risk, since doing so makes it technically possible for intruders to access many machines on the network at once.
Cost considerations: Installing a local area network is a relatively expensive project. Servers, cabling, switches, routers and software can all be expensive and should never be purchased without expert advice. Keeping the network operating and secure also requires a lot of resources and can be costly.
Surprisingly, a local area network can bring a number of cost savings. Sharing resources avoids the need to purchase equipment for each individual. Even more important is the security that a local area network can provide. Data loss could cost a business a great deal of money and in some cases, cause the business to shutdown altogether. Computer Network Management should require a consistent routine for data backups with regular checkups of data quality - a practice that will save a company huge sums in the event of a mishap.
Computer Network Management: preliminary analysis phases
The first phase of computer network management is to determine the source of the problem (a preliminary study that looks into several options of differing scope may be useful here) and defining it in a specification of requirements. Examples of what should be evaluated are different network operating systems, mail systems, and other applications. The choice of hardware components should also be evaluated. This phase is generally aimed at establishing what the system should do, not how it should do it.
Computer Network Management: design phase
The purpose of design phase is to determine how the requirements of the specification are to be met. The current approach to large, complex projects is to break them down into smaller, more manageable subprojects.
Computer Network Management: implementation phase
This phase involves the physical installation of the local area network. Cables are run, software is installed, and computers and other hardware are put in place.
Computer Network Management: integration and system testing phase
In this phase, commissioning of the network begins, and routines are adapted to users and the operating personnel. The system must be tested, both to ensure that the network meets the requirements set out in the specification and that it is stable enough to perform the central function it has in the organization.
Computer Network Management: operation and maintenance
Local area networks have complex operating routines. This is because there may be serious consequences when faults occur or unauthorized persons gain access to the system. Many companies have employees devoted solely to take care of running and maintaining computer networks. These system administrators may deal with network issues such as performance, reliability and security of both hardware and software.
Friday, February 03, 2006
Computer Network Engineering Online
Online Computer Network Engineering Schools teach the necessary skills required to design, install, configure, and maintain enterprise-wide networks. Through a distance learning course, students can study Computer Network Engineering at their own convenience to develop skills in computer applications, writing, communications, and problem solving in a technical environment.
Online Schools help prepare professionals for Computer Network Engineering positions such as network administrator, systems administrator, technical support specialist, help desk technician, and computer support specialist. The Computer Network Engineering curriculum includes training in UNIX, HTML, database applications, desktop computing, network essentials, Microsoft network operating systems, Internetworking, and enterprise administration.
With the rapid advancements in modern business technology, an online degree in Computer Network Engineering can boost employment and earning potential. Employers prefer those with a technical diploma, and there are many accredited online colleges and universities offering degrees in Computer Network Engineering. Distance learning makes it possible to obtain an Associate, Bachelor or Master of Science degree without ever stepping foot in a classroom.
Depending on education and experience, a Computer Network Engineering professional can earn an annual salary of $45,000 to $95,000, or more.
Online Schools help prepare professionals for Computer Network Engineering positions such as network administrator, systems administrator, technical support specialist, help desk technician, and computer support specialist. The Computer Network Engineering curriculum includes training in UNIX, HTML, database applications, desktop computing, network essentials, Microsoft network operating systems, Internetworking, and enterprise administration.
With the rapid advancements in modern business technology, an online degree in Computer Network Engineering can boost employment and earning potential. Employers prefer those with a technical diploma, and there are many accredited online colleges and universities offering degrees in Computer Network Engineering. Distance learning makes it possible to obtain an Associate, Bachelor or Master of Science degree without ever stepping foot in a classroom.
Depending on education and experience, a Computer Network Engineering professional can earn an annual salary of $45,000 to $95,000, or more.
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