When we look at the differences between logical design and physical design of a network it is easy to think of it as the logical as the functional part and physical as the seeing it part.
With that stated there is more to this than just the functional and seeing parts. In order to understand the differences from one to the other, we need more information. In the following paragraphs I will try to outline what makes up the differences between logical and physical design of a network.So let’s first look at what constitutes a logical design of a network.
The first thing we know is that the logical design is, “The part of the design phase of the SDLC in which all functional features of the network chose for development are described independently of any computer platform. ” There are other ways to describe a logical network, but the one that comes to mind is how the network will be structured. Basically we are talking about all of the logical aspects of the network.According to Webopedia, “the logical topology is the way the data passes through the network from one device to the next without regard to physical interconnection of the devices.
” Also the logical design lacks specific details such as technologies and standards and focuses on the general needs of the network. A logical design can be a view of any part of the network, whether it be the whole or just a part of it. Another element of the logical design is the IP addresses and their association with the different parts of the network.The IP addresses are assign to devices such as routers, switches, servers, workstations, and other devices that utilize the network.
In the logical design we usually do not show the actual interfaces and physical cables in the diagrams; thus giving us the true meaning of the term “logical. ” IP structure is a big part of the logical design of a network as well as security planning. A good logical design will have the foundation for security which provides the framework stages needed for security.Each layer should have scalable security services that involve the routers, switches, servers, workstations and other devices that are utilizing the network.
In some cases the logical design is described using the terms of the customer’s business. Processes, roles, and even locations can show up in the logical design; however, the important aspect of the logical design is that it is part of the requirement set for a solution to a customer’s problem (Jim’s Weblog, 2005).Below is an illustrated example of a logical design of a network: Now that we have looked at the logical design, let’s take a look at the physical design of a network. The basic idea behind the physical design is to communicate what hardware should be used in the network.
The physical design of the network is derived from the logical design and the physical design will often expand on the elements found in the logical design. For example, let’s say that the logical design shows a WAN connection as line between to buildings.When this is transformed into a physical design, that single line could expand into the connection, routers and other equipment at each end of the connection (Jim’s Weblog, 2005). The physical design also involves the specific technologies and products that are realized from the logical design.
This involves the actual devices that will be used to get the logical design to work. The physical design also will involve the topology that will be used in the network.The physical topologies vary and there are many to choose from such as the Ring topology, the Bus topology, the Star topology, the Mesh and many others depending on the needs of the customer. A Ring topology would be: All devices are connected to one another in the shape of a closed loop, so that each device is connected directly to two other devices, one on either side of it (Webopedia, 2006).
A Bus topology would be: All devices are connected to a central cable, called the bus or backbone. Bus networks are relatively inexpensive and easy to install for small networks.Ethernet systems use a bus topology. A Star topology would be: All devices are connected to a central hub.
Star networks are relatively easy to install and manage, but bottlenecks can occur because all data must pass through the hub (Webopedia, 2006). So when we refer to the physical design we are talking about the actual physical layout of the network. This includes the cables, switches, workstations, routers, and servers. The physical design involves a diagram of the actual way the network will be seen.
Below is an illustrated example of the physical design of a network:In conclusion, the difference between logical design and physical design of a network is in the way they are presented. The logical being the one that shows how the data flows and the physical showing the devices and connections of the network. You can think of logical and physical as like cars and roads. The roads represent the physical network where each road is interconnected and the cars represent the logical where when they move towards a certain destination within the network.
Although logical and physical networks vary, they still work together to better define the same network.
Da Vinci Code Characters
Langdon:He is a professor of symbology at Harvard. He is kind and extremely intelligent, and is a popular academic and author of several books at the same time. Hes an expert in religion and he is really good at solving puzzles and mysteries, so he solves Jacques Saunieres dying message (which is a puzzle) with Sophie.
Sophie:She is about 30 years old and works in French Judicial Police as a cryptologist. She lived with her grandfather since she was very young because her parents died in a car accident. She is really intelligent and is an expert in solving puzzles like Robert Langdon.Jacques Sauniere:Hes the curator of Louvre and the grandfather of Sophie.
He really likes Leonardo Da Vinci and puzzles (both making and solving). When Sophie was young, he always gave Sophie puzzles. And he knows what the Teacher wants to know, so he gets murdered at the beginning of the book.The Teacher:He requests a monk of Opus Dei (a religious group) named Silas to threat Jacques Sauniere to make him tell the secret of the Holy Grail, and kill him.
Conflict:Jacques Sauniere told Silas the wrong information, which was a good thing. And Silas killed him even though he thought what Sauniere said was the secret, because the Teacher told him to kill him. However nobody except Sauniere knew the secret, so just before he died he left a super complicated puzzle which only professor Langdon and Sophie could solve. However the police think Langdon is the murderer of Sauniere.Louvre:Louvre is where Jacques Sauniere was murdered and left a puzzle for Langdon and Sophie.France:The story takes place in present time, and mostly in France.
Hessian (German) Soldiers (Mercenaries) In The Revolutionary War
When it comes to the Revolutionary War, everyone’s first thought is identical.
While the Americans fought against the British to gain their independence, it is important to note that there were also individuals fighting on the British side who made significant contributions to their numbers.
The Hessian soldiers, also called German Mercenaries by some historians, were employed by the British during the American Revolution (American). Their role in Britain’s mobilized armies raises questions about their identity and influence. The origins of the Hessian army can be traced back to King Charles of Hesse-Kassel, who hired out soldiers as mercenaries to foreign nations in order to boost national finances (Reese).
The country of Hesse-Kassel was situated between two sections of Prussia, amidst crucial military routes (Showalter). As a consequence, this led to warfare between the two nations on various fronts. The rural areas were devastated, and war became a predominant topic of discussion among the people. Therefore, when King Charles proposed this plan, it appeared to be a standard means of bolstering finances.
The Hessian army was initially small and unimportant. However, a plan was introduced to sell soldiers for profit. This led to the army being divided into smaller cantons, with each canton responsible for maintaining a field regiment for defending their own homes (Showalter). The selection process for soldiers under this plan was straightforward. All men between the ages of 16 and 30 who were taller than a certain height were considered eligible for military service. However, individuals who owned property valued at more than 250 thalers had the option to pay the army in money instead of serving as soldiers.
The group of people exempt from military service in Hesse-Kassel included craftsmen, apprentices, slave workers in military-related industries, and men vital for the success of their farms. Consequently, Hesse-Kassel managed to maintain an army of 24,000 men, establishing itself as the most militarized state in Europe, with a ratio of one soldier per every 15 citizens (Showalter). Although foreigners were permitted to join the expanding army of Hesse-Kassel, the majority of soldiers were native-born sons. Surprisingly, the soldiers primarily consisted of individuals without land, employment, or a fixed residence.
Military inspectors from different European countries often commented on the size and physical condition of the Hessian regulars. They believed that their fitness was a result of their strict upbringing and continuous involvement in warfare (Showalter). People often wondered about the feelings of the Hessians towards being sold into war, and it is true that they had a unique acceptance of military life. Once enlisted, the only means of leaving the military was through death, becoming a fugitive, or committing 24 years to military service (Showalter).
The motivation behind Hessian soldiers going to war was the stories they had heard in their childhood from their parents and grandparents, which portrayed war as adventurous but excluded the devastating and painful aspects. However, not all Hessians wished to be perpetually engaged in warfare. In order to avoid desertion by soldiers before their duty, parents were held accountable and imprisoned if their sons fled from battle. They would only be released from jail once their sons reported for duty (Showalter).
Despite their strict rules and regulations, the Hessian army gained a reputation as a formidable fighting force through their actions in battle. Prior to joining the British in the Revolutionary War, the Hessians were employed in various conflicts by other countries, serving as mercenaries. During this time, Hesse-Kassel was not known for its military prowess or any other distinguishing factors. Recovering from wars was a slow process for them, making it challenging to maintain a strong force and protect their borders and political stability (Showalter).
In 1676, they had a small army of only 23 companies. They lent all of their companies to Denmark for 3,200 thalers and later rented out 1,000 men to Venice for 50 thalers each. This caught the attention of the Estates of Holland.
In 1658, a group of 3,400 soldiers under Sir William of Orange was sent to the Estates of Holland to engage in a campaign. The Dutch, impressed by their performance, desired to have more Hessian soldiers for longer periods of time. As a result, the Hessians participated in subsequent wars such as the League of Harissburg (1688-97) and the Spanish Succession (1701-14), earning a formidable reputation as skilled soldiers. The news of the Hessian soldiers’ prowess reached Prince Eugene of Austria, who promptly enlisted 10,000 of them to join him in Italy in 1706 and later fought against the Turks in Hungary.
Although the Hessians were often perceived as mercenaries motivated by money, they saw their military service as a means of preserving sovereignty in Hesse-Kassel, rather than as a profit-making endeavor. In fact, even five sons of the king fought in battles, and sadly, two of them were killed (Showalter). Despite their military exploits, the Hessians remained steadfast in their native Calvinist beliefs and steadfastly refused to engage in any business with Protestant employers. France, a Protestant country, made numerous generous offers to Hesse-Kassel for soldiers but each time they were turned down due to Hesse-Kassel’s commitment to their religion (Showalter).
During the Scottish rebellion in Britain in 1715, British authorities enlisted 12,000 Hessian soldiers to suppress the uprising. Subsequently, as a gesture of gratitude, Britain agreed to pay Hesse-Kassel an annual sum of 125,000 pounds to secure priority access to the Hessian army in future conflicts. However, after five years passed without any signs of war, the British reached a settlement with Hesse-Kassel: a flat payment of 240,000 pounds in exchange for the readiness of 12,000 soldiers for British service (Showalter). Although Hesse-Kassel maintained the reserved troops for the British, they attempted to rent out the remaining soldiers to other nations but with no success.
Both sides of the War of the Austrian Succession witnessed the participation of the Hessians (Showalter). However, during the Seven-Years War, the Hessians had a significant presence on the battlefield with 24,000 men, surpassing the British by 2,000, thereby making a notable impact in the conflict. Demonstrating their exceptional skills, the Hessians once again proved to be among Europe’s finest soldiers as the American Revolution approached. The British referred to them as His Britannic Majesty’s Army in Germany (Showalter). With the American Revolution looming, the Hessians prepared to showcase their most memorable performance.