Saturday, January 25, 2020
OSI MODEL Essay -- essays research papers
Michael Rauseo                                        IT310                         OSI Model In the early years of computer and network research and development many systems were designed by a number of companies. Although each system had its rights and were sold across the world, it became apparent as network usage grew, that it was difficult, to enable all of these systems to communicate with each other. In the early 1980s, the International Organization for Standardization (ISO) recognized the need for a network model that would help companies create common network implementations. The OSI reference model, released in 1984, addresses this need. The OSI reference model became the primary architectural model for communications. Although other architectural models have been created, most network vendors relate their network products to the OSI reference model. The OSI model describes the processes necessary for effective communication in terms of a seven layered model. The seven layers are : Physical Layer The physical layer defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between end systems. Such characteristics as voltage levels, timing of voltage changes, physical data rates, maximum transmission distances, and physical connectors, are defined by physical layer specifications. Data Link Layer The data-link layer provides error-free transfer of data frames from one computer to another over the physical layer. The layers above this layer can assume virtually error-free transmission over the network. The data-link layer provides the following functions. - Establishing and terminating a logical link between two computers identified by their unique network interface card. - Controlling frame flow by instructing the transmitting computer not to transmit frame buffers - Sequentially transmitting and receiving frames - Providing and expecting frame-acknowledgment, and detecting and recovering from errors that occur in the physical layer by ret... ...cation layer of one system will be readable by the application layer of another system. If necessary, the presentation layer translates between multiple data representation formats by using a common data representation format. The presentation layer concerns itself not only with the format and representation of actual user data, but also with data structures used by programs. In addition to actual data format transformation, the presentation layer negotiates data transfer syntax for the application layer. Application Layer The application layer is the OSI layer closest to the user. It differs from the other layers because it does not provide services to any other OSI layer, but rather to application processes lying outside the scope of the OSI model. Examples include spreadsheet programs, word-processing programs, banking terminal programs, etc. The application layer identifies and establishes the availability of intended communication partners, synchronizes cooperating applications, and establishes agreement on procedures for error recovery and control of data integrity. Also, the application layer determines whether sufficient resources for the intended communication exist. []
Friday, January 17, 2020
What Important Skills Should a Person Learn to Be Successful?
â€Å"What important skills should a person learn to be successful in the world today? †Nowadays, becoming a successful person is one of the first targets of humans . People succeed doesn't depend on who are they – musician, president, businessman etc. It doesn't depends only on having certain skills. Today , various skills contribute to success. I think, that any person can become successful through learning from the mistakes, being able to take risk and having the persistence. In my opinion, one of the important skills that a person should have in order to be successful is learning from the mistakes.We know that nobody is perfect on doing something, especially if he or she does it for the first time. Before achieving any goals, humans can make a lot of mistakes. Some people become grieved and lose their self – confidence when they do mistake. This disappointing ends with failure in your job or in your successful development. While making mistakes, if we feel s orry for ourselves then we will have failure, but, if we accept the lesson from our mistake then we will move to a successful life.Except learning from the mistakes, being able to take a risk is also one of the main keys of success. Any person, who want to achieve success must not afraid of risk, they should not see the risk as a danger. Taking a risk could result a lot of positive outcomes, and it can be very profitable. According to co – founder of Zipcar company Robin Chase, †Taking professional and entrepreneurial risks is quite profitable . My decision at age 23 to illegally slip into Kenya from Tanzania was a greater risk than launching Zipcar with just $78 in my bank account.Today Zipcar has 350,000 members using 6,500 cars. †Taking real risk also requires freedom in our expectations and fears. Not all people can have such freedom, that's why not everybody can take risks and be successful. In addition to learning from the mistakes and being able to take a risk, having the persistence is also one of the main points of being successful in the world. Today, any person can achieve success by developing his or he persistence to a very high level. In order to reach any goal and succeed , person should take sequential actions.I think, that it is the biggest problem of many people not to be sequential, staying out of the race in reaching finish and persistence. In brief, today everybody wants to be prosperous, beginning from the trucker to the doctor. It is not so easy to succeed. It requires some necessary abilities, such as: having self- assurance through learning from mistakes, being bold to take any risk and having perseverance. These keys are very important and basis in achieving success. Therefore, I think, †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.
Thursday, January 9, 2020
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