Open Systems Interconnection model

Open Systems Interconnection model Introduction The international organisation for standardization ISO, in its bid to streamline and regulate the networking sector, introduced the OSI labelling techniques. The OSI layer labelling operates as a guide post to provide a universally accepted framework for implementing networking protocols. (Hallbarg 2001)Advertising We will write a custom essay sample on Open Systems Interconnection model specifically for you for only $16.05 $11/page Learn More OSI layers The OSI are divided into seven layers labelled in integers from 1 to 7. The layers are arranged in a stratum whereby layer 7 is in the top and the bottom layer is 1. Physical layer This layer determines the electrical and physical stipulation for the devices. This layer plays a significant role of specifying the connection between the device and the medium of transmission. The physical layer is focused in the reception of signals through the physical medium. It defines the transmission techniqu e and the medium through which these techniques are conducted. Data link layer This layer is relegated into two sub groups, in this layer; the data transmitted is essentially assigned specific and appropriate physical property. The transmission is done through wireless routers e.g. the 802.11 Wi-Fi these physical properties would include such features like the medium of transfer. This layer is also responsible in the delimitation of the network type and the packet sequencing procedure of the network. It uses DCA and LAC protocol Network layer This is the third layer in the series. The network layer determines the manner in which data is sent to other devices. The determination of router tangents and the recipient address. This layer is classified into three sub layers depending on the logical schemes of apportioning addresses. It employs the use of MPLS switching component with ICM,IGM and IGR protocols. (Hallbarg 2001) Transport layer The fourth layer acts as the main conducting ve ssel of data. It provides an avenue for establishing errors and debugging these errors. It sustains the movement and flow of data between the devices. Its main component is the DNS systemAdvertising Looking for essay on it? Let's see if we can help you! Get your first paper with 15% OFF Learn More The layer effectively decides the path-physical that the data takes through the existing media. Under the transport layer, the TC and the UD protocols exist. Session layer The fifth layer in the OSI series is the session layer. The layer is responsible for the regulation of the communication between the interconnected computers. Its primary functions have been listed to be Creation/establishment of connection between computers Management of the already established communication between the remote and the local computers Ending the communication between the computers. The main component in the session is SOCKets. (Hallbarg 2001) Presentation layer It is the sixth l ayer in the series. It is referred to as the presentation layer due to its ability to deliver data from the session layer and present it to application layer into a favourable format that can easily be decoded. It essentially has a primary role of transmutes data into a form that is acceptable to the application. The core protocols include JPEG, ASCII, EBCDIC and TIFF. (Hallbarg 2001) Application This is the window interface where end users interact with the application. It is very important in the synchronisation of the existing communication. Through this layer, various processes like messaging, remote access to computer files, network management and resource sharing.It uses FTAM , HTT, CMI, FT and SMT protocols. (Hallbarg 2001) Reference Hallberg, B. A. (2001). Networking a beginners guide (2nd ed.). New York: Osborne/McGraw-Hill. Print

The Russians Renamed St. Petersburg Three Times in a Century

The Russians Renamed St. Petersburg Three Times in a Century St. Petersburg is Russias second-largest city after Moscow, and throughout history, it has been known by a few different names. In the more than 300 years since it was established, St. Petersburg has also been known as Petrograd and Leningrad, though its also known as Sankt-Peterburg (in Russian), Petersburg, and just plain Peter. The city has a population of about 5 million people. Visitors there take in the architecture, especially historic buildings along the Neva River and its canals and tributaries flowing in the city that connect Lake Ladoga to the Gulf of Finland. Being so far north, in the middle of summer, the citys daylight extends nearly 19 hours. Terrain includes coniferous forests, sand dunes, and beaches. Why all of the names for a single city? To understand the many aliases of St. Petersburg, look no further than the citys long, tumultuous history.   1703: St. Petersburg Peter the Great founded the port city of St. Petersburg on the very western edge of Russia in 1703 in a marshy floodplain. Located on the Baltic Sea, he desired to have the new city mirror the great Western cities of Europe, where he had traveled while studying in his youth. Amsterdam was one of the primary influences on the czar, and the name St. Petersburg has a distinctly  Dutch-German influence. 1914: Petrograd St. Petersburg saw its first name change in 1914 when World War I broke out. The Russians thought that the name sounded too German, and it was given a more Russian-sounding name. The Petro start of the name retains the history of honoring Peter the Great.The -grad  portion is a common suffix used in a number of Russian cities and localities. 1924: Leningrad It was only 10 years that St. Petersburg was known as Petrograd because in 1917 the Russian Revolution 503 changed everything for the country, including the citys name. At the beginning of the year, the Russian monarchy was overthrown, and by years end, the Bolsheviks had taken control. This led to the worlds first communist government. Vladimir Ilyich Lenin led the Bolsheviks, and in 1922 the Soviet Union was created. After Lenins death in 1924, Petrograd became known as Leningrad to honor the former leader. 1991: St. Petersburg Fast-forward through almost 70 years of the communist government to the fall of the USSR. In the years that followed, many places in the country were renamed, and Leningrad became St. Petersburg once again. Historical buildings saw renovation and rejuvenation. Changing the city name back to its original name did not come without controversy. In 1991, the citizens of Leningrad were given the opportunity to vote on the name change. As reported in the New York Times at the time, some people saw restoring the citys name to St. Petersburg as a way to forget the decades of turmoil during communist rule and an opportunity to reclaim its original Russian heritage. The Bolsheviks, on the other hand, saw the change as an insult to Lenin. In the end, St. Petersburg was returned to its original name, but you will still find some people who refer to the city as Leningrad.