A Review On Public Switch Data Networks Information Technology Essay

A Review On Public Switch Data Networks Information Technology Essay A public data network is a network established and operated by a telecommunications administration, or a recognized private operating agency, for the specific purpose of providing data transmission services for the public. A public switched data network (PSDN) is a publicly-available packet-switched network, distinct from the PSTN. A general wide area network used to provide circuit switched data services for commercial users A publicly-available network supporting packet-switched data It is an all digital communications line that allows for the transmission of voice, data, video and graphics, at very high speeds, over standard communication lines It is a computer network that uses a public telecommunication infrastructure such as the Internet to provide remote offices or individual users with secure access to their organizations network. It aims to avoid an expensive system of owned or leased lines that can be used by only one organization. A leased line is a service contract between a provider and a customer, whereby the provider agrees to deliver a symmetric telecommunications line connecting two or more locations in exchange for a monthly rent (hence the term lease). It is sometimes known as a Private Circuit or Data Line in the UK. Dial-up Internet access is a form of Internet access that uses the facilities of the public switched telephone network (PSTN) to establish a dialed connection to an Internet service provider (ISP) via telephone lines. The users computer or router uses an attached modem to encode and decode Internet Protocol packets and control information into and from analogue audio frequency signals, respectively. Feature Caller ID, Call Waiting, Voice Mail, and Call Forwarding à ®Ã¢â€š ¬Ã¢â€š ¬Need a connection establishment between end nodes. à ®Ã¢â€š ¬Ã¢â€š ¬Connection is maintained until one of end nodes terminates. à ®Ã¢â€š ¬Ã¢â€š ¬Connection is dedicated to the communication between two nodes. à ®Ã¢â€š ¬Ã¢â€š ¬Reduces the number and the total length of the links Data are transmitted in short messages called packets. à ®Ã¢â€š ¬Ã¢â€š ¬A connection between the two end-nodes is not maintained. à ®Ã¢â€š ¬Ã¢â€š ¬A node-to-node link can be dynamically shared by many packets. à ®Ã¢â€š ¬Ã¢â€š ¬Example : Public Data Network (PDN) likes X.25, Frame Relay. There are two types of PDN: CSPDN and PSPDN. Mostly used to provide leased-line connections between local area networks and the Internet Circuit switch network work by allowing multiple sessions to run between end-user by simply switchingto the most direct or available path Because a circuit switch dedicates bandwidth to each session, it is less effective from packet-switch. The advantage of circuit switch is transparent, and the path is always open, thus the delay through SCPDN is constant, which is ideal for real time application such as video. One of the disadvantage of CSPDN is they are very wasteful of bandwidth, because if the device is not transmitting data, the bandwidth will always be availalbe. Packet switch provide bandwidth on-demand. Advantage of PSPDN is it saved bandwidth, because they only use the bandwidth when there is data to transmit. All data in Packet switching is transmitted in frame/packets over a trunk, where each packet or frame can belong to a different session. All of the data being sent to the network is marked with a sequence number. This mean PSPDN can correct any data corrupt or loss within a network. Disadvantage of PSPDN is buffering. It builds on groups of standard transmission channels. Bearer channels (or B channels) transmit user information at relatively high speeds, while separate Data channels (or D channels) carry call set-up, signaling and other information. It handles all types of information. Unlike some other digital communications technologies, ISDN handles all types of information voice, data, studio-quality sound, still and moving images. They are all digitized, and transmitted at high speeds in the same flow of data. It handles many devices and many telephone numbers, on the same line. It encapsulates data transfers between two or more networked devices which are not on the same private network so as to keep the transferred data private from other devices on one or more intervening local or wide area networks. There are many different classifications, implementations, and uses for VPNs. Typically, leased lines are used by businesses to connect geographically distant offices. Unlike dial-up connections, a leased line is always active. The fee for the connection is a fixed monthly rate. The primary factors affecting the monthly fee are distance between end points and the speed of the circuit. Because the connection doesnt carry anybody elses communications, the carrier can assure a given level of quality. Dial-up connections to the Internet require no infrastructure other than the telephone network. Dial-up is often the only choice available for rural or remote areas where broadband installations are not prevalent due to low population and demand. Dial-up access may also be an alternative for users on limited budgets as it is offered free by some ISPs, though broadband is increasingly available at lower prices in many countries due to market competition. Network Interface Circuit-switched Packet Switching Packet Switching Circuit-switched Packet Switching Device-to-device interfaces are called reference points Interface R Located between Non-ISDN Terminal Equipment (TE2) and a Terminal Adapter (TA) Interface S/T Located between ISDN user equipment and Network Termination (NT1) equipment Interface U Located between NT1 equipment and an ISDN central office RJ45/RJ11 RJ45/RJ11 RJ45/RJ11 Components/ hardware configuration Consists of telephone lines, fiberoptic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables all inter-connected by switching centers which allows any telephone in the world to communicate with any other. In a LAN packet-switched environment, such as with an Ethernet network, the transmission of the data packets relies on packet switches, routers, and LAN cables using permanent virtual circuits (PVCs). Uses TDM (Time Division Multiplexing), SDH (Synchronous Digital Hierarchy) and PDH (Pleisochoronous Digital Hierarchy) Uses Frame Relay and STDM (Statistical Time Division Multiplexing) TE1- Any ISDN-ready device that connects directly to ISDN or connects to ISDN via an NT1. For example: a digital telephone, a GT 70 Series router. TE2- Any non-ISDN device that needs to be used with a Terminal Adapter (TA) to work with ISDN. For example: an analog FAX, PC, or analog telephone. TA-A device that converts non-ISDN communication to ISDN to allow non-ISDN devices to work with ISDN. NT1- A device located between the S/T and U reference points that allows communication between functional devices. Secure VPNs use cryptographic tunneling protocols to provide confidentiality by blocking intercepts and packet sniffing, allowing sender authentication to block identity spoofing, and provide message integrity by preventing message alteration. Leased lines are made up of the following components: a router, usually managed by the service provider, is installed into a customers comms room. The circuit is presented with an RJ45 connector as standard. local loop circuit, , links the router to the service providers local point of presence (POP). Network termination equipment (NTE) is attached to the wall in a comms room and is connected to either a fibre optic or copper local loop circuit. depending upon location, a back haul circuit may be used to link a customer to their service providers point of presence and then onto the internet gateway. This will take place behind the scenes and may run over a third partys national network. Protocols X.25 X.25 X.25 X.25 X.25 The LAPD (Link Access Protocol Channel D) is a layer 2 protocol Ipsec (Internet Protocol Security) SSL (Transport Layer Security) DTLS ( Datagram Transport Layer Security) SSH (Secure Shell VPN) Point-to-Point Protocol (PPP) Multi-Link Point-to-Point Protocol (ML-PPP) NetWare connect Point-to-Point Protocol (PPP) Multi-Link Point-to-Point Protocol (ML-PPP) NetWare connect Standards ITU-T, E.1263, E.164 CCITT/ITU-T ITU-T ITU-T ITU-T CCITT Q.920/921 IETF Wide Area Network Standard Wide Area Network Standard

Defensive Driving

Defensive Driving Defensive driving is a method of driving I utilise which helps me to anticipate the actions of others in order to maintain safety for myself and vehicle plus my passengers in any road and weather conditions. I pay extra attention to my speed, judging gaps and distances, pulling off and braking, reversing and manoeuvring and tiredness/fatigue. By constantly looking and anticipating as far ahead as I can see, I can be prepared for potential hazards and associated risks before I get there. Observing what vehicles on either side or oncoming are doing and making constant use of my rear view mirrors further assists me in being a safe driver. Being aware of my vehicles’ characteristics, instruments and safety features are important factors. Knowing any blind spots on my vehicle and its dimensions are especially useful when reversing and manoeuvring. I am constantly aware of all that is happening around me, for example, when reversing I check for any potential hazards around and behind the vehicle before I move. Other vital factors are early and timely use of indicators, hazard warning lights, vehicle lights, hand signals and correct use of the horn in an emergency, as is regular maintenance and servicing. Smooth, careful acceleration and braking is important for safety and also good for the environment too. Examples of this are reduced fuel consumption, creating less pollution and prolonging the efficient working life of my vehicle. Stress and fatigue levels are also greatly reduced and, as adopting this driving policy inevitably reduces the chances of having an accident, my insurance premiums are keenly priced. Utilising all these methods and instruments correctly ensures a much higher degree of safety for me, my vehicle, my passengers, other road users, pedestrians and animals. In my opinion, I am a safe driver M. G. Spivey 17th May 2010

What Impacts Will the Aging Population of Germany Have on Its Economy

The objective of this research paper is to explore, analyze and survey the implications of Germany’s demographics on the country’s economy. The motivation behind this study is to add to the understanding of social-economic issues in one of the Eurozone’s heavyweights and its impact for years to come. This paper looks into Germany’s demographic trends, consumption trends, savings trends, Germany's pension policy and labor market effects.This paper draws on estimates and analyses from relevant literature, including scholarly journals and government publications to illustrate and quantify its points. Conclusions drawn from this study shows that the definitive impact of population aging on economic growth is reflected in consumption, savings, labor pool and dependency burdens. Practical implications can be surmised from this paper; policy makers, native citizens, immigrants and other stakeholders might wish to refer to this paper for an understanding and persp ective of the social phenomenon and derive solutions to problems in its sphere.However there are limitations to this research as it is done through literature review and the demographic-economic variables are not constant. Further research will be required to gather concise and quantifiable data to support its claims. Introduction Germany's aging problem is serious because during the past 30 years, German women have produced children at an average rate of less than 1. 4 babies per lifetime (Tim Colebatch, 2004). In 2009 The Federal Statistic's Office (Germany) forecast Germany's rapidly aging population was likely to decline by 20 percent to around 65 million by 2060.The drop will be accompanied by a dramatic shift in the amount of elderly people in Germany. Of the country's current 81 million inhabitants, some 20. 6 percent are now aged 65 (2011). But in 2060, assuming that fertility rate remain constant and life expectancy increase at a steady rate, that percentage will increase t o 33 percent. Following a rapid recovery from the 2008-2009 recessions, economic growth has slowed in the second half of 2011 for Germany (OECD,2012).Policy makers are faced with domestic issues interfering with mid-term growth potential, one of them namely rapid population aging. Deutsche Bundesbank published a report in April 2012 announcing that if the dampening effects of demographics can be mitigated by appropriate reform measures, it will largely be possible to maintain the current rate of potential growth of roughly 11/4% per y ear until 2020. With Europe struggling to cope with the Debt Crisis, an economic powerhouse such as Germany is under the pressure to come up with solutions and lead the union.However with its workforce fading into bottomless vacuum of tax dependents, it does not reflect well onto Germany’s financial health and strength as a sovereign nation. This paper intends to examine the situation in Germany and reach a conclusion that population aging incre ases the dependent population burden in views of both taxpayers and the nation’s budget; aggregate consumption expenditure decreases; the savings rate declines and shrinks the pool of available capital; working-age population reduces, while the labor productivity in Germany is not impacted heavily.Moreover, this paper will outline a perspective stakeholders should adopt to illustrate that as long as effective reform or measures can be implemented, the negative impact of the aging population on economic growth is likely to be minimized. Main arguments Dependency burdens Population aging increases the dependent population burden. Germany's pension system is known as the most generous pension system and public welfare. Costs of public retirement insurance are almost 12% of GDP, more than 2. times as much as the U. S. Social Security System (Axel Borsch-Supan, et al. ,2003), and it accounts for a high proportion of retirees' income. The weight of this tremendous systems is taxing on Germany's finances as well as the need for tax-payers' support. To ease the pressure of an aging population on the government budget, Germany has carried out a series of reforms. In what was called â€Å"the greatest social reform after war â€Å"by former Labor Minister Franz Liszt initiated in the spring of 2001.The main contents include reducing benefits, settling the level of premium expenditure, a pay-as-you-go pension system and developing a new type of private pension to fill the loss of welfare income. This reform, especially with measures to expand private pension types, will probably promote economic development. The Fund pension system is conducive for German government to supply a large number of retirees without increasing the load of employees and taxpayers. From a macroeconomic perspective, this series of system can help reduce the government budget pressure from an aging population.From micro-economic perspective, it can also bring higher personal income. Unfor tunately, there is a big difference between the actual implementation of Liszt reform and the government's promise. The new fund pension system in Germany is being undertaken on a relatively small scale, while the current non-accumulation fund insurance system is still in the highest flight. The final result is that, the German retirees are almost entirely likely to depend on the government. Overall, the public welfare accounted for 61% of net income after tax for families of 60 years old or above.The substantial increase in social welfare spending for the elderly in the GNP will continue to enlarge, as it is bound to limit the expanding of production, and influence the capital investment and economic efficiency, and add the burden on the national economy. Thus, with the development of population aging and extension of the average life expectancy of the aging of the population, it might be appropriate to extend the retirement age limit, in order to reduce dependent population and re latively increase the accumulation funds to expand production.Germany plans to raise the retirement age to 67 years of age, because of such considerations. But at the same time, the heavy new employment pressure requires Germany to strike a balance between extending retirement age and easing the employment pressure. Consumption The next section puts forward the argument that with the on-set of population aging, an increasing share of the elderly in the German market caused changes in its consumption structure.Overall, the consumption expenditure shows a gradual widening tendency during the aging process; however, Germany has already entered the aging society, so consumption expenditure showed a decreasing trend. This table shows the percentage of elderly family with an excess of the annuity income over expenditures. Annuity income is more than consumer spending and it increases with age. The decline in consumer spending is so significant that for about a quarter of the elderly aged 75 and above, the annuity income is more than 50% higher than consumer spending.In fact, almost all of this decline can be attributed to a decrease of food, travel and traffic expenses, the marginal utility of consumption reduction will probably decrease in the elderly, due to deteriorating health or being lonely. It is worth noticing that in Germany, food, travel and traffic expenses can hardly be offset by more health spending, because almost all health fees are covered by compulsory health insurance. (Wise, 2004) To some extent, the influence of population aging on consumption inhibited economic development.In this case, to speed up the development of older industries, government should focus on the development of travel, real estate and pension services for older people in order to promote consumption growth and the prosperity of the silver hair market. Savings The world's population is aging, accordingly, bank balances might probably stop growing. People tend to reduce their sa vings after retirement, while the younger generation are not as canny as older generations. As a result, savings rate will drop significantly (Diana Farrell, et al. , electric shavers, 2005).Because aggregate saving equals to investment (Lachlan McGregor, 2008), so if left unchecked, the slowdown of the global savings rate will reduce the amount of money available for investment and then hinder economic growth. It is not easy to find a solution. Stimulating economic growth in itself is not a solution, nor is the future productivity revolution or technological breakthroughs. To add to future global savings and financial wealth, the German government and the family need to increase their savings rate, and earn a higher return on assets. These changes involve tough choices, but it can provide a brighter future.As the elderly make up the larger proportion of the population, the total amount for investment and wealth accumulation will be reduced. The expected decline of growth rate for G ermany's financial wealth will fall to 2. 4% from 3. 8%. One thing is certain: the decline in the household savings rate can shrink the pool of available capital. Because of continuing budget deficit, government may push up interest rates and crowd out private investment. In the next few years, the rise in the cost of economic dependence will force government to implete better fiscal discipline.The only meaningful way to offset the population pressure to the upcoming global financial wealth is increasing savings rate of government and households, and a more efficient allocation of capital for the economy, thereby increasing the return. In Germany, to achieve the required rate of return, the policy makers must improve competitiveness, encourage innovation in financial sector and the economy as a whole, and raise the legal protection of investors and creditors. As for increasing the savings rate, the key to is to overcome inertia.When the enterprises automatically register their emplo yees on a voluntary savings plan rather than requiring people to become active, participation rate might increase significantly. Of course, the government can also increase the savings rate of Germany directly. Labor Pool With an increase in the proportion of the elderly population, the proportion of working-age population will accordingly decrease, which goes against German economic development (David E. Bloom, et al. , 2001). Labor force can be an effective motivation of rapid economic growth.However, a demographic draft report of the German federal government indicated that the working age population may reduce from 50 million to 26. 5 million in 2050, which is a decrease of nearly a half. According to the draft, the employment reduction would bring disastrous consequences to the economy of Germany. Moreover, it is much more difficult for older workers to adapt to the fast-paced production activities, especially in the labor-intensive production, so population aging is not conduc ive to the improvement of labor. In this case, a targeted immigration plan is very useful to enable Germany' to maintain its competitiveness.It is estimated that in order to make the employment potential of Germany remain at the level in 2004, at least 300 thousand to 500 thousand immigrants are needed annually. The appeal of that idea stems from two considerations: immigrants are relatively young, and hence their arrival reduces the average age of both the population and the labor force; and they can be expected to add more to the national product than they use up as consumers in terms of health-care, and thus to provide net support for the rising numbers of elderly dependents in the population.On closer inspection, however, there is a problem: immigrants get older, like everyone else, and a sustained policy of higher immigration has little long-term impact on either the median age or the age composition of the population. As Espenshade (1994, p. 766) noted, â€Å"immigration is a clumsy and unrealistic policy alternative to offset a shortage of domestic labor or to correct a perceived imbalance in the pensioner to worker ratio. †The effect of population aging to enhance labor productivity is negative which can be reflected on that the speed of aging workforce to accept new knowledge, science and technology is slower than that of the young. Relatively the elderly population shows a weak ability to adapt to new industries. Thus, to some extent, new product development and technological innovation are largely influenced by the aging problem. In the case of rapid scientific and technological development, and faster advancement of knowledge and increasingly keen competition, population aging has greater negative influence on labor productivity and economic growth.As for Germany, it gives priority to technology-intensive industries and to improve labor productivity mainly relies on science and technology, so the demand for mental exertion is much higher tha n physical. As a result, the negative influence of population aging on increase labor productivity is likely to be limited, on the other side, the experience of skilled older workers will have a positive effect to improve labor productivity in Germany. Conclusion Overall, it is argued in this essay that population aging in terms of the acroeconomics is not conducive to economic development, and its negative impact is mainly manifested in the above-mentioned four areas, while the elderly population do not entirely represent an economic burden as they can be profitable consumers, among them there are still some people engaged in economic activities with relatively abundant accumulation of experience and knowledge which can make up for the physical insufficiency. Thus, to some extent, these people contribute to the economic development.In fact, an effective way to mitigate the adverse effects of an aging population and labor force, is by accelerating the development of a knowledge-base d economy in high-tech industries. (i. e. to improve the level of automation in production and reduce the demand for workers' physical strength. ) We should also see that the development of the knowledge-based economy led to changes in the industrial structure and occupational structure and the increasingly high demand for workers intelligence.With the expectancy of population average life, the health status of the elderly is gradually improving, older workers will make a greater contribution than ever for economic development. Therefore, the rational development and utilization of elderly human resources, will become an important issue to mitigate the adverse impact of population aging on economic development. AppendixPercentage of Elderly in Age Group with a Ratio of Annuity Income to Consumption Expenditures in Germany [pic] Bibliography Asghar Zaidi and Malgorzata Rejniak (2010). Fiscal Policy and Sustainability in View of Crisis and Population Aging in Central and Eastern Europ ean Countries. Axel Borsch-Supan et al. (2005). aging, pension reform, and capital flows:a multi-country simulation model. Cambridge. National Bureau of Economic Research.David A. Wise (2004). Studies in the Economics of Aging. National Bureau of Economic Research. David E. Bloomet al. (2001). Economic Growth and the Demographic Transition. Cambridge: National Bureau of Economic Research. David N. Weil (2006). Population Aging. Cambridge. National Bureau of Economic Research. Michael D. Hurd (2006). The Economics Of Individual Aging. University of New York at Stony Brook.

Who Invented Graham Crackers

They may seem like an innocuous treat today, but Graham crackers were once on the front lines to save America’s soul. Presbyterian minister  Sylvester Graham  invented Graham Crackers in 1829 as part of a radical new dietary philosophy. Sickly Sylvester Graham Silvester Graham was born in West Suffield, Connecticut in 1795 and died in 1851. His early life was marked by such poor health that he chose the ministry as a less stressful profession. In the 1830s, Graham was a minister in Newark, New Jersey. There he formulated his radical ideas about diet and health—much of which he adhered to for the rest of his life. The Graham Cracker Today, Graham may be best remembered for his promotion of unsifted and coarsely ground wheat flour, which he liked for its high fiber content, and for the fact that it was free of commonplace additives alum and chlorine. The flour was nicknamed graham flour and is the main ingredient in Graham Crackers. Graham Crackers represented to Graham all that was good about the earth and its bounty; he believed that a high-fiber diet was a cure for a variety of ailments. In the era in which he grew up, commercial bakers followed a trend for white flour that removed all fiber and nutritive value from wheat which many people, including and especially Sylvester Graham himself, believe sickened a generation of Americans. Grahams Beliefs Graham was a fan of abstinence in many forms. From sex, sure, but also from meat (he helped to found the American Vegetarian Society), sugar, alcohol, fat, tobacco, spices, and caffeine.  He also insisted on bathing and brushing the teeth on a daily basis (before it was necessarily commonplace to do so). Graham held a wide variety of beliefs, recommending not only the varieties of abstinence outlined above but also hard mattresses, a lot of open fresh air, cold showers, and loose clothing.   In the hard-drinking, hard-smoking, and hard-breakfasting 1830s, vegetarianism was regarded with deep suspicion. Graham was attacked repeatedly (in person!) by bakers and butchers, who were offended and threatened by the power of his reformist message. In fact, in 1837 he was unable to find a place to hold a forum in Boston because local butchers and commercial, additive-loving bakers were threatening to riot. Graham was a well-known—if not particularly gifted—lecturer. But his message hit home with Americans, many of whom harbored a puritanical streak. Many opened Graham boarding houses where his dietary ideas were enacted. In many respects, Graham predated the mania for wellness and spiritual renewal that would suffuse the later 19th Century in America, and—along with other cultural phenomena like the invention of breakfast cereal—lead to a revolution in the diet of a nation. Grahams Legacy Ironically, today’s Graham crackers wouldn’t meet the minister’s approval at all. Made largely of refined flour and loaded with sugar and trans fat (in this case called partially hydrogenated cottonseed oil), most are pale imitations of Graham’s soul-saving biscuit.