Networks Essays - Local Area Networks, IEEE Standards, Free Essays

Networks Essays - Local Area Networks, IEEE Standards, Free Essays Networks Network, in computer science, techniques, physical connections, and computer programs used to link two or more computers. Network users are able to share files, printers, and other resources; send electronic messages; and run programs on other computers. A network has three layers of components: application software, network software, and network hardware. Application software consists of computer programs that interface with network users and permit the sharing of information, such as files, graphics, and video, and resources, such as printers and disks. One type of application software is called client-server. Client computers send requests for information or requests to use resources to other computers, called servers, that control data and applications. Another type of application software is called peer-to-peer. In a peer-to-peer network, computers send messages and requests directly to one another without a server intermediary. Network software consists of computer programs that establish protocols, or rules, for computers to talk to one another. These protocols are carried out by sending and receiving formatted instructions of data called packets. Protocols make logical connections between network applications, direct the movement of packets through the physical network, and minimize the possibility of collisions between packets sent at the same time. Network hardware is made up of the physical components that connect computers. Two important components are the transmission media that carry the computer's signals, typically on wires or fiber-optic cables, and the network adapter, which accesses the physical media that link computers, receives packets from network software, and transmits instructions and requests to other computers. Transmitted information is in the form of binary digits, or bits (1s and 0s), which the computer's electronic circuitry can process. Network Connections A network has two types of connections: physical connections that let computers directly transmit and receive signals and logical, or virtual, connections that allow computer applications, such as word processors, to exchange information. Physical connections are defined by the medium used to carry the signal, the geometric arrangement of the computers (topology), and the method used to share information. Logical connections are created by network protocols and allow data sharing between applications on different types of computers, such as an Apple Macintosh and an International Business Machines Corporation (IBM) personal computer (PC), in a network. Some logical connections use client-server application software and are primarily for file and printer sharing. The Transmission Control Protocol/Internet Protocol (TCP/IP) suite, originally developed by the United States Department of Defense, is the set of logical connections used by the Internet, the worldwide consortium of computer networks. TCP/IP, based on peer-to-peer application software, creates a connection between any two computers. Media The medium used to transmit information limits the speed of the network, the effective distance between computers, and the network topology. Copper wires and coaxial cable provide transmission speeds of a few thousand bits per second for long distances and about 100 million bits per second (Mbps) for short distances. Optical fibers carry 100 million to 1 billion bits of information per second over long distances. Topology Common topologies used to arrange computers in a network are point-to-point, bus, star, and ring. Point-to-point topology is the simplest, consisting of two connected computers. The bus topology is composed of a single link connected to many computers. All computers on this common connection receive all signals transmitted by any attached computer. The star topology connects many computers to a common hub computer. This hub can be passive, repeating any input to all computers similar to the bus topology, or it can be active, selectively switching inputs to specific destination computers. The ring topology uses multiple links to form a circle of computers. Each link carries information in one direction. Information moves around the ring in sequence from its source to its destination (see Computer Architecture). Local area networks (LANs), which connect computers separated by short distances, such as in an office or a university campus, commonly use bus, star, or ring topologies. Wide area networks (WANs), which connect distant equipment across the country or internationally, often use special leased telephone lines as point-to-point links. Sharing Information When computers share physical connections to transmit information packets, a set of Media Access Control (MAC) protocols are used to allow information to flow smoothly through the network. An efficient MAC protocol ensures

Free Essays on A Moment to Remember

A Moment to Remember It was a sharp pain in my shoulder as I was going through hitting drills in football practices. That day everything was going very well. Even though the day was hot, steaming, and exhausting, I was full of energy. As we started the hitting drills, I was trying to impress the coach with everything I had. With me being a sophomore trying to play varsity football, I had to give it my all. The moment in which I remember the most is one that will affect the rest of my life. It was when my shoulder dislocated for the first time in football practice. The pain was agonizing, intense, and very expensive. As I was growing up and becoming interested in football. I played my heart out in every game having the feeling as if I was invincible. Moving up from J.V. to varsity football was an experience in which I was scared of. Wondering if maybe I could perform at the same level in which I always have. In being a leader to the rest of my teammates and also excelling in the classroom. As practice started, I felt anxiety running all through my body, trying not to show it and at the same time it was quite obvious. From that point on I knew this season was going to be horrible. On the day I dislocated my shoulder, there were no warning signs leading up to the intense pain I was about to feel. With me feeling great that day. I felt as if I was invincible to anyone who went up against me. We were doing hitting drills in practice that day. I was going against the starting fullback from the previous football season. I t was a way in which I could prove myself worthy. As we were hitting head up against each other, I was making him look really bad; to the point where he was getting real frustrated with himself. Then as went up against each other for the last time in practice, it happened. My shoulder was knock out of place. I jumped, shouted, and scream all at the same time. The feeling was painful becau... Free Essays on A Moment to Remember Free Essays on A Moment to Remember A Moment to Remember It was a sharp pain in my shoulder as I was going through hitting drills in football practices. That day everything was going very well. Even though the day was hot, steaming, and exhausting, I was full of energy. As we started the hitting drills, I was trying to impress the coach with everything I had. With me being a sophomore trying to play varsity football, I had to give it my all. The moment in which I remember the most is one that will affect the rest of my life. It was when my shoulder dislocated for the first time in football practice. The pain was agonizing, intense, and very expensive. As I was growing up and becoming interested in football. I played my heart out in every game having the feeling as if I was invincible. Moving up from J.V. to varsity football was an experience in which I was scared of. Wondering if maybe I could perform at the same level in which I always have. In being a leader to the rest of my teammates and also excelling in the classroom. As practice started, I felt anxiety running all through my body, trying not to show it and at the same time it was quite obvious. From that point on I knew this season was going to be horrible. On the day I dislocated my shoulder, there were no warning signs leading up to the intense pain I was about to feel. With me feeling great that day. I felt as if I was invincible to anyone who went up against me. We were doing hitting drills in practice that day. I was going against the starting fullback from the previous football season. I t was a way in which I could prove myself worthy. As we were hitting head up against each other, I was making him look really bad; to the point where he was getting real frustrated with himself. Then as went up against each other for the last time in practice, it happened. My shoulder was knock out of place. I jumped, shouted, and scream all at the same time. The feeling was painful becau...

Waiting for a Delayed Flight Essay Example | Topics and Well Written Essays - 750 words

Waiting for a Delayed Flight - Essay Example The implications of such a delay are equally very costly, not only to an individual traveler but also to the flight company as well (Forbes, 2). Flight delays result from such reasons as repair and maintenance of the aircraft, security issues domestically or within the intended destination, issues stemming from the airport crew as well as possible delays in the arrival of the respective aircraft. Other causes may be such as delays in baggage loading, furling, traffic congestion and such natural calamities as unfavorable weather conditions. In the event that such unfortunate occurrences happen, passengers awaiting departure often suffer greatly. The result of delayed flight includes lateness for strategic appointments, failure to meet deadlines as well as losses from delayed delivery of perishable products among others. Besides such losses, individuals often are stranded within the airport and are likely to incur other costs such as in refreshments as well as securing personal accommo dation services in case the delay is beyond a single day. I happened to experience a flight delay in a leading African tourism destination where I spent my summer holiday last year. This formed a memorable experience in my life has never experienced such in my years of air travel. Though accompanied by my parents, I felt so much devastated by the experience because this was the first time I experienced such a delay. The airport had very disturbing loud noises from the landing and taking off air engines, which made me have a very severe headache. My parents decided to take a stroll in the neighborhood of the airport but I was unable to accompany them due to a headache I suffered. They took me to one of the waiting bays where barely anyone else was and left me lodged on a chair as is shown by the picture. This was equally no comfortable as the disturbing noises were still very loud and clear. Moreover, the sight of the landing and taking off planes kept disturbing me as the waiting ba y provided a very clear view of the running lanes.