Local Area Network - Assignment Example

Running head: Local Area Network Local Area Network in APA Style of College or A collection of computers connected together in small geographical space is known as a local area network (LAN). In other words, a LAN is a local computer network, which allows computers to communicate with each other. The network usually consists of computers, word processors, and other electronic equipment that allows different offices to communicate. (WordNet, n.d.) Computers in the network are also considered as "nodes". There must be a medium that connects these computers and the medium can be either wired or wireless. Other equipment that are necessary include routers or hubs. In a LAN only one machine act as domain server which allows other client machine to log in onto the network in order to share resources, both software and hardware. Software can take the form of a centralized database, distributed application or can be a collection of simple utilities, which might be shared on a computer with in the domain. Similarly hardware can be a printer or a centralized storage device. LAN offers the fastest data transfer rate up to 10 Mbps. Stair & Reynolds (2001) suggest that usually, LAN is wired into office buildings, factories, school buildings, etc and are built around personal computers (PC). When a PC is connected to a LAN, a network interface card (NIC) is required which is placed in a computer's expansion slot to allow it to communicate with the network. A wire or connector from the network is then plugged directly into NIC. (Stair & Reynolds, 2001, p. 138) In order to install and configure a LAN setup in a school, the topology should have to be selected. Out of the three topologies, i.e. ring, bus and star, star topology is the most feasible one, as due to the failure of a computer or a segment of wire or a node, the other network nodes would not be affected at all. For star topology the basic hardware required for connectivity are as follows: Switches or Hub For a smaller LAN with a maximum of 10 computers Hub works fine but for a larger LAN a switch gives better efficiency compared to a hub. The reason is that the hub broadcast the data packet to every node, hence all other nodes except the destination node thereby ignoring the broadcasted data packet where as the switch store the MAC addresses of each node and would send the data packet only to the destination node. UTP (Unshielded Twisted Pair) cable: This type of cable is the most feasible one as it is cheaper and it gives a data rate of 10 Mbps. Further more in a larger LAN setup, if the distance between two switches or between switch and a terminal (computer) is more than 100 meters than we have to use a repeater device, which enhances the signal strength so that it can reach the destination. Hence for every 100 meters we have to use a repeater device. Apart from these network components, all the computers, which are going to participate as a node in the network must have a LAN card. Every computer must have to be joined directly to a switch by the help of single twisted pair cable. In case of larger number of computer, then the switches should have to be connected with each other by the help of cross twisted pair cable connection. When all the computers are physically connected with each other to form a LAN setup, then the network operating system should have to be installed and configured on every computer so that they can communicate with each other. Since a LAN must have at least one domain server so in order to make a computer to act as domain server, we have to install a server operating system like Windows 2003. After that install and configure ADS (active directory services) on that server computer. Create user accounts and register every network resource within the ADS. Further more in the ADS, privileges can be assigned individually to every user account, so that when a user logins from a client computer, he can access only the allowed resources. For rest of the client computers, we have to install windows XP operating system on every computer and log in every computer on to the domain. The more computers that are connected, the more than LAN traffic increases. Then there is a need for better performance. Ethernet Switching Information (n.d.) explains in further detail: If this were the only source of increased traffic, LAN upgrades could be confined to backbones that interconnect multiple LANs. Current bridges and routers could divide large LANs into multiple LANs at no great increase in cost per desktop, keeping the ratio of computers to individual LANs at a level that would produce acceptable performance. New applications, however, create a more significant kind of traffic increase: they cause the traffic per desktop to increase. The shift to client-server computing splits applications between server computers and client (desktop) computers. The resulting communication over the LAN between clients and a server produces much greater LAN traffic per desktop than applications centered mainly in the desktop or in the server. A study conducted by NOP World Technology on behalf of Cisco Systems reveals that the logical benefits of wireless LANs still require the educating of the market and public. Although wireless LANs help companies reach areas such as education, healthcare, government, and manufacturing and contribute to greater production rollouts, knowledge regarding wireless LANs still needs to be delivered. Benefits that people need to know include increasing employee production by allowing them the convenience of working at home, on the road, and/or at the office. Greater company financial returns upon the implementing of wireless LANs, improved accuracy in work, and the ease of using portable devices (such as PDA) are among other benefits. When benefits are realized, people tend to want to employ what is offered, have a better understanding, and can see the value of the new technology. Barriers to change and levels of deployment are also affected by the spreading of benefits of wireless LAN usage. References Stair M. Ralph & Reynolds W. George, (2001) Fundamentals of Information Systems: Course Technology: Thomson Learning WordNet. (n.d.) Retrieved January 3, 2007, from http://wordnet.princeton.edu/perl/webwns=lan Network Security 1 Running head: Network Security Network Security in APA Style Name of Student Name of College or University Network Security 2 Network Security Introduction "Every computer is a network" or so the saying goes. Every computer because it is connected to the Internet or to the local intranet has become a part of the network. This makes the PC as much susceptible to the vulnerabilities of the network as any other network might be. The nature of the vulnerabilities that a location is exposed to is remarkable. The usage of the Internet has multiplied manifold. This by itself leads to a number of ways by which the world might find ways of cheating or robbing an honest person. Some vulnerabilities are exploited by people who want to make money. However, there are also others who do it for the entertainment. The internal vulnerabilities are to be countered so that possession is not used by the other. The Need for Security The PCs in the school are used by a number of people including students and staff. But there are at least ten times more students who use the computers compared to a staff. Students in a school are to be exposed to learning exercises in the Internet and not to the other derogatory experiences that one might get on the Internet. The Internet is a source of both good and bad. It is the duty of the person to segregate them and use them as he deems fit. However, in the case of the students, on many occasions, they may not be in the right position to identify whether what they are doing is right or wrong. Therefore, the responsibility lies with the staff to ensure that they educate themselves appropriately and not in any other way. Network Security 3 There was once a time where information was only in hard copy form. Information was stored on paper. Pfleeger and Bloom (2005) describes the simplicity of keeping information secure back when information was stored only on paper, "It's easy to protect information stored on paper: we can limit the number of copies or keep them in a safe place, maybe even under lock and key. It's also easy to limit the flow of this information from one place to another because of the effort needed to copy and transmit it from sender to receiver; paper transmission mechanisms aren't designed for cheap and effortless" Then companies (including schools) started adding technology such as computer and network-related resources. Now most information is stored electronically via the Internet. Electronic mail, or e-mail, is one of the most popular services that the Internet has to offer. Electronic mail, or e-mail, has become one of the most popular uses for the Internet. However, with the introduction of spam (unsolicited bulk electronic mail), because of its many devastating effects. Nariyoshi, Okayama, Miyashita, Maruyama, and Nakamura (2003-2004) report in their abstract that spam mail devastatingly interfere with the Internet community in many ways including: 1. Users receiving many spam mails have to take much time for picking up valuable non-spam mails 2. The resources of mail servers and networks are wasted by the traffic of spam mails. 3. If the sender of spam mails is spoofed to an address of an existing domain, Network Security 4 the spoofed sender and/or domain are misled to originate the spam mails. 4. If the sender of spam mails is spoofed to addresses of an existing domain, then huge volumes of spam mails sent to non-existing users are bouncing back to the MTA of the domain, and consequently the MTA is overloaded by massive error mails. There are other security issues and consequences that spam mail delivers to businesses. E-mails can deliver messages that are offensive, disruptive, and frightful to recipients. Spam may contain messages that are offensive such as comments about disabilities, age, religion, sexual orientation, political beliefs, including offensive comments about race, gender, hair color, disabilities, age, sexual orientation, pornography, natural origin, religious beliefs and practice, etc. Chain letters cannot only be annoying but frightful to recipients as they can be a hoax warning about viruses and bad luck. Joke e-mails may also creation various negative reactions. These types of e-mails usually contain false information, which are misleading. Security in Schools The security in schools is very important. Providing security helps to insure that no viruses or worms come into the system and that there is no unsolicited visitor into the network. The security should also insure that the students are provided access to websites and e-mails that they are allowed Network Security 5 to see and are not provided permission for those that they are not allowed. This security is implemented in the school using the following: 1. Hard firewall has been provided at the entry of the internet in to the school campus. This protects the network from unsolicited visitors over the network and hacking is stopped by this process. There is no intrusion detection software that has been put in place since the vulnerabilities foreseen does not show a large probability of people making unsolicited visits breaking through the firewall. 2. An online anti-virus, anti-worm and anti-Trojan system has been implemented on the network. This works on one of the servers and uses a thread to keep track of the file transfers and communications to ensure that there is no virus movement or signature. 3. The firewall also provides for settings to stop access to specific certifications in the sites accessed. This is set appropriately to ensure that the students do not access the unwanted web sites. In the school, the students are not allowed to access even the mail based websites since that would start off a new communication channel. 4. Internal vulnerabilities are countered by employing appropriate password protected network and continue maintaining it that way. Ssolutions to providing security include filters, reverse lookups, challenges, and cryptography. First and foremost, a school should have policies in dealing with technology and information assets for all who have involvement. Technologies and policies exist that address the problem of spam e-mail. Forming a security policy, guidelines that one must follow in order to gain access to a business's technology and information assets, in the area of education are crucial. Informing those Network Security 6 who have any dealings with the school such as students/users, staff, and managers of their responsibilities for protecting technology and information assets is the main reason for a security policy. Vendors and others who deal with the school may also need to be informed of the policies. Conclusion Therefore, school is also vulnerable and might get hacked; spoofed or such other damaging mechanisms might be employed to collect information from the school and its students/staff. The security in the school with regard to the virus, worms and Trojans would be to counter them with the utmost severity to stop them when they do occur. For the others, adequate security depending upon the level of protection sought. References Equiinet, 2005, Network Security in schools. Retrieved October 5, 2005, from http://www.equiinet.com/securepilot/networksecurity/Equiinet_Security%20Report_colour.pdf Pfleeger, Shari Lawrence and Bloom, Gabrielle (2005). Canning Spam: Proposed Solutions to Unwanted Email. Published by the IEE Computer Society 1540-7993/05 2005 IEEE IEEE Security & Privacy Robert Brumfield, R. (2005.) Schools need Improved IT Security. eSchool News online. Retrieved October 5, 2005, from http://www.eschoolnews.com/news/showstory.cfmArticleID=5923 Network Telecommunication 1 Running head: Network Telecommunication Network Telecommunication in APA Style Name of Student Name of College or University Network Telecommunication 2 Telecommunication Systems in a Cybercafe The cybercafe business has two essential hardware which are the computer terminal and the link to the Internet. The business I own uses desktop computers with central processing units that utilize 512Kb double-data-rate synchronous dynamic random access memory (DDR SDRAM), an 80-gigabyte harddisk with an independent 128Kb video card. It has a DVD ROM and DVD writer and floppy disk drive as well as USB ports. The monitor is a flat-screen 15" SVGA CRT monitor. The computer also has headphones with built-in microphones and a USB web camera for videoconferencing as well as online chatting. Many people make video calls to people in other countries, usually families and friends, over the Internet at a low hourly rate at the cybercafe. They can use instant messaging service such as MSN or Yahoo! Legal Resources (2007) gives more detail about instant messaging, "Instant Messaging is a form of electronic communication which involves immediate correspondence between two or more users who are all online simultaneously." The computers are Local Area Network (LAN) capable with built-in modems. A LAN is collection of computers connected together in small geographical space. The LAN is a local computer network, which allows computers to communicate with each other. The network usually consists of computers, word processors, and other electronic equipment that allows different offices to communicate. (WordNet, n.d.) Computers in the network are also considered as "nodes". There must be a medium that connects these computers and the Network Telecommunication 3 medium can be either wired or wireless. Other equipment that are necessary include routers or hubs. The computer can be connected directly to an ordinary phone line for dial-up Internet access. But this is not a real option for a serious Internet surfer or video caller as dial-up speeds only go as high as 96 kilobytes per second (kbps), and result in jerky video or really slow opening of the site, especially if it is graphics heavy. Another option is using the modem or the LAN to connect to a digital subscriber line (DSL). The DSL is still a physical line, basically a telephone wire but exclusive for computer use. For Internet access, I use an asymmetric digital subscriber line (ASDL) through the local telecommunications company. The term "asymmetric" means upload and download speeds are not the same, as opposed to a "symmetric" DSL service. (Franklin) The connection I have has a top download speed of 1 Gigabyte per second and a top upload speed of 512 kbps, provided the RJ 45 cables do not exceed 18,000 feet. The line is accessed through an ADSL modem provided by the telecom company. The ADSL modem is connected to a wireless broadband router with four wired terminals. The ADSL modem in turn is connected to a switch that enables me to split the access to as many as eight desktop computers per wired terminal without significant decrease in connection speed. Wired terminals are connected via the LAN with RJ 45 to provide what is commonly know as an "ethernet" connection. Wireless computers may access the network as well as the router has access points but the speed of the connection diminishes directly with the number of wireless users. Network Telecommunication 4 The specifications above allow users to play LAN as well as online games, connect to E-mail and instant messaging services as well as online station-to-station chatting with audio- visual capabilities. The computer also allows facsimile and other digital documentary transmittals as well as document creation. Peripheral equipment includes a scanner which allows the user to scan images or documents for archiving, editing, uploading or printing. The memory card reader is used to download images from a digital camera or mobile phone and the printer provides all kinds of hard copy. The peripherals need not be provided for each terminal as the computers are all networked, so this equipment are "shared" by one master terminal or server. All these systems provide some type of communication: the LAN connects computer to computer; the switch connects all the computers to the router; the router connects the switch to the ADSL modem; the modem connects user to the ADSL; and the ADSL connects all users to the Internet. Policies for using the cybercafe are posted and staff are encouraged to help customers adhere to them. Without policies and a security procedure in place, the computers can be bogged with spam (unsolicited e-mails which have devastating consequences). Other issues and problems can create electronic, physical, and legal results. There is a variety of software available that will assist in the management of a cybe rcafe. One type of software uses the MicroSoft Windows operating system. Some software combine all the functions necessary in order to manage a cyber caf. Software also provides network support which connects a number of computers in the caf. Some can provide support Network Telecommunication 5 for over 250 computers. The type of management desired and required will determine which software will be used. Some managers prefer a more manual, hands-on type of management. While others prefer the technology and ease of software to do most of the work. How much automation is wanted and needed varies significantly with each cyber caf based on various factors. Research and knowing the market will assist in determining which route is the best one to take. References Franklin, C. How DSL Works How Stuff Works retrieved December 20, 2006 from http://www.howstuffworks.com/dsl.htm Legal Resources. (2007.) Kroll Ontrack. Retrieved January 5, 2007, from http://www.krollontrack.com/legalresources/glossary.aspx WordNet. (n.d.) Retrieved January 3, 2007, from http://wordnet.princeton.edu/perl/webwns=lan Read More