Datalink layer essays

Datalink layer essays 2.0 PURPOSE Networking, are becoming essential and common in computer communication in small business, big companies and even home network. Networking is two or more computers linked together using communication medium and run by hardware and software components. The data communication is broken down into several tasks, where one is built over the other. These tasks are handled by entity which interacts with adjacent entity, for example the lower entity support the upper entity. These entities are listed below: 1. Application layer generates data to be transmitted 2. Presentation layer accepts messages generated by the application layer. 3. Session layer to set up dialogue between 1 applications 4. Transport layer ensures all messages are delivered correctly 5. Network layer responsible for collecting and routing the data 6. Data Link layer prepare messages for physical transporting 7. Physical layer transmitting data over the communication medium The seven layer of entity is called open systems interconnection (OSI) model. The OSI model allows communication between different types of computer systems. This assignment focuses on the 2nd layer of the OSI model, how it interacts with adjacent layers, purpose of the layerfunctionality of the layer, protocols and hardware. 2.0 Purpose According Forouzan 2003 data links layer hold a vital role as a second layer in the open standard interconnect (OSI) model. It transmitted information from layer 3 and received data from layer 1.It primary function is to pass a data message to another network or node. Data Link layer work as a filter that check and label wether the data can be send or receive from the next layer. The data link layer also must ensure that the incoming data arrive exactly like it was transmitted by the sender. If the data is corr...

cryptonym - definition and examples of cryptonym

cryptonym - definition and examples of cryptonym Definition A cryptonym is a word or name thats secretly used to refer to a particular person, place, activity, or thing; a code word or name. A well-known example is Operation Overlord, the cryptonym  for the Allied invasion of German-occupied western Europe during World War II. The term cryptonym is derived from two Greek words meaning hidden and name. See Examples and Observations below. Also see: Name That -nym: A Brief Introduction to Words and NamesPseudonym Examples and Observations Cryptonyms are  often temporary, are known to only a select group of people, and are usually of unrelated or at best covert meaning. Some  cryptonyms are  simply combinations of letters and figures.(Adrian Room,  An Alphabetical Guide to the Language of Name Studies. Scarecrow, 1996)Reinhard was the cryptonym for the German plan to exterminate the Jews of Poland.(MichaÅ‚ Grynberg, Words to Outlive Us: Voices From the Warsaw Ghetto. Macmillan, 2002) White House CryptonymsThe Oval Offices next occupant opted for this moniker [Renegade] after being presented with a list of names beginning with the letter R. As custom dictates, the rest of his familys code names will be alliterative: wife Michelle is known as Renaissance; daughters Malia and Sasha are Radiance and Rosebud, respectively.(Renegade: President-elect Barack Obama. Time magazine, November 2008) CIA CryptonymsThe true identities of  cryptonyms are  among the most precious secrets of the Central Intelligence Agenc y (CIA).- The CIA often used multiple cryptonyms for the same entity to strengthen operational security and maintain compartmentalization of the information.In the CIA nomenclature, cryptonyms always appear in capital letters. The first two letters were used for cryptographic security and were based on factors such as the geography or type of operation.  The rest of  the cryptonym  was a word selected randomly from a dictionary, in principle with no particular relation to the place or person  the cryptonym  was supposed to mask. However, it is not difficult to imagine tongue-in cheek CIA officers picking words like wahoo for Albanian, drink for Greece, credo for Rome, gypsy for communist, roach for Yugoslavia, crown for United Kingdom, steel for Soviet Union, and metal for Washington, D.C.(Albert Lulushi,  Operation Valuable Fiend: The CIAs First Paramilitary Strike Against the Iron Curtain. Arcade, 2014)- Vladimir I. Vetrovwho had the cryptonym FAREWELLreported to Weste rn intelligence services that the Soviets had placed bugs on the printers used by the French intelligence service for communications.(Ronald Kessler, Inside the CIA. Simon Schuster, 1992)- The longtime personal physician of the Castros mother and some of her daughters was a reporting source. Bernardo Milanes, known to  the Agency by  his cryptonym  AMCROAK, was recruited in December 1963 in Madrid. At the time he and others were plotting an assassination attempt against [Fidel] Castro.(Brian Latell,  Castros Secrets: The CIA and Cubas Intelligence Machine. Palgrave Macmillan, 2012)-  The Farm was known officially by the  cryptonym  ISOLATION. The names of places and operations were a special language in the Agency.(Don DeLillo,  Libra. Viking, 1988)-  Flower was the overall top-secret code-name designator given to anti-Qaddafi operations and plans. Only about two dozen officials, including the President and Casey, were given access.Under Flower, Tulip was the code name for a CIA covert operation designed to topple Qaddafi by supporting anti-Qaddafi exile movements.(Bob Woodward, Veil: The Secret Wars of the CIA, 1981-1987. Simon and Schuster, 2005) Pronunciation: KRIP-te-nim