Open System Interconnect Model and Todays Networks Research Paper

Open System Interconnect Model and Todays Networks - Research Paper Example It is important to note that OSI modal is an abstract or conceptual model and often OSI model layers overlap functions and protocols in real networks. The first layer of OSI model is known as physical layer because it deals with physical media use to interconnect various machines in a network. This may include connectors, UTP and fiber optic cables or wireless access points, hubs, repeaters etc. Data at this layer is in the format of bits or electrical signals. The next comes the Data Link layer which is used to control the access to the communication channel described in the first layer. This layers also set the pace of data flow over the data communication channel. Various devices used at this layer includes switches and bridges. Data at this layer is in the format of frames. The devices are identified based on their physical address at this layer and MAC address is used to address source and destination machines. High-level Data Link Control (HDLC), Frame Relay, PPP etc. are some the protocols used at Data Link layer. Network layer is basically used for logical addressing of source and destination machines. IP Address are used this layer of the OSI Model. Router is the most important device used at this stage. It is an important layer where various protocols like IP, Internet Control Messaging Protocol (ICMP), Address Resolution Protocol (ARP), Reverse Address Resolution Protocol (RARP) etc are used. This layer ensures movement of data to corrected logical address of the machines. with accuracy and request retransmission if required. More importantly in today’s network for fast communications this layer ensures the selection of most optimal route through Open Shortest Path Fist (OSPF), Extended Gateway Protocol (EGP), Routing Information Protocol (RIP) and many other protocols. Data is organized in packet at this layer. Transport layer transports and sequences packets in to data segments. It eliminates duplication and recovers data losses. It controls the overall flow of data and ensure accuracy and concurrency between communicating devices. TCP, UDP and NetBEUI are important protocols used at transport layer. Session layer opens, maintains, and closes session between applications. These sessions synchronize data communication between machines on a network. Various

Personal financial planning Essay Example | Topics and Well Written Essays - 250 words

Personal financial planning - Essay Example However where this healthcare system differs is that the insurance would not be run for profit and healthcare is provided to all people. Beveridge: This system of healthcare owes its namesake to William Beveridge who helped spearhead reforms in Great Britain’s National Health Service. Ultimately funding was to be drawn from taxpayers so the healthcare system becomes a government run institution (Like the fire departments, police forces, schools etc.) Many doctors and hospitals would be run and paid for by the government, and there would be private doctors & specialists who would receive payments from the government. Some hospitals (Such as veterans hospitals) may be run like this in the U.S. but overall this does not closely resemble the overall American system. Medicare: This loosely resembles the Canadian model which is sort of a hybrid of both the Bismarck and Beveridge systems. There exists both a private sector provider (Bismarck) but funding also comes from the governmen t which draws its funding from the tax base (Beveridge). So in essence there is no real incentive to deny claims insofar as there is no incentive to generate a profit.