The Seven Layer Osi Model

The Seven Layer Osi Model Seven-layer OSI model is a logical layer and developed by the ISO international standardization organization. The purpose of this layer is to understand the transmission of data flows from source to destination and to identify problems during data transmission. The seven layers include Application, Presentation, Session, Transport, Network, Data link and Physical layer. The sequence of layer names to be remembered by this phrase All people seem to need data processing. The following is a general description of each layer. OSI reference model is now being considered as the main model for the internetworking and inter computing. The seven layers divide the task of data transmission in sub tasks and then complete the data transmission cycle. QUESTION 1 In the 1980s, the European-dominated International Standards Organization (ISO) began to develop its Open Systems Interconnection (OSI) networking suite. OSI has two major components: an abstract model of networking (the Basic Reference Model, or seven-layer model), and a set of concrete protocols. Briefly explain each of the seven OSI layer included their function and usage in data communication and networking. OSI Reference Model OSI reference model (Open Systems Interconnection) illustrates how information from a software application on a computer moves through a network medium to a software application on another computer. OSI reference model is conceptually divided into 7 layers where each layer has a specific network function, as described by figure 1.1 (with no physical media). This model was created based on a proposal made by the International Standards Organization (ISO) as a first step toward international standardization of protocols used at various layers. à ¯Ã‚ ¿Ã‚ ½This model is called ISO OSI (Open Systems Interconnection) Reference Model because this model is intended for sharing open systemà ¯Ã‚ ¿Ã‚ ½.[1] Open Systems can be interpreted as an open system to communicate with other systems. For his brief, we will call this model as the OSI model only. Figure 1.1. OSI Reference Model OSI model has seven layers. The principles used for the seven layers are: 1. A layer must be made when needed different levels of abstraction. 2. Each layer shall have certain functions. 3. The function of each layer should be chosen carefully in accordance with the provisions of international protocol standards. 4. Layer boundaries labored to minimize the flow of information through the interface. 5. The number of layers must be quite a lot, so that different functions do not need to be united in a single layer outside needs. However, the number of layers must also be cultivated as little as possible so that the network architecture does not become difficult to use. Below discuss about each layer of the OSI model sequentially, starting from the bottom layer. It should be noted that the OSI model itself is not network architecture, because this model does not explain the exact services and protocols to be used on any layer. OSI model only explains about what should be done by a layer. However, ISO has also established standards for all layers, although these standards do not constitute a reference model itself. Each layer has been declared as a separate international standard. Characteristics of the OSI Layers To seven layers of OSI reference model can be divided into two categories, namely upper and lower layers. The top layer of the OSI model deals with application issues and generally implemented only in software. The highest layer (application layer) is the cover prior to the user (users), both users and application layer processes interact with software applications that contain a communication component. The term upper layer is sometimes used to refer to some of the top layer of another coating layer in the OSI model. The bottom layer of the OSI model to control data transport issues. Physical layer and data link layer implemented in hardware and software. The layers below the others are generally only implemented in software. à ¯Ã‚ ¿Ã‚ ½The lowest layer, the physical layer is a layer of cover for the physical network medium (cable networks), and as responsible for the placement of information on the network mediaà ¯Ã‚ ¿Ã‚ ½.[2] The following table shows the separation of the two l ayers in the layers of the OSI model. Application Application Overlay Presentation Session Transport Data Transport Undercoat Network Data Link Physical Table 1.2 Separation of top layer and bottom layer of the OSI model Protocol OSI model provides a conceptual framework for communication between computers, but this model is not a method of communication. In fact communication can occur due to use of communication protocols. In the context of data networks, a protocol is a formal rules and agreements that determine how computers exchange information over a network medium. A protocol implements one or more of the layers of the OSI. A wide variation of the communication protocol, but all maintains the flow in one group: the LAN protocols, WAN protocols, network protocols, and routing protocols. LAN protocols operate at the physical and data link layer of the OSI model and define communication over various LAN media. WAN protocols operate at the third lowest layer of the OSI model and define communication over various WAN. Routing protocol is a network layer protocol that is responsible for determining the road and traffic arrangements. Finally, the network protocol is different from the upper layer protocols th at exist in a series of protocols. Layers of the OSI Model Physical Layer Physical Layer functions in the delivery of raw bits into the channel of communication. Design issues that must be considered here is to ensure that when one side sends data 1 bit, the data must be accepted by the other side as a bit too, and not 0 bit. The question that arises in this case is: how many volts should be used to declare a value of 1? And how many volts is also required for the number 0?. It takes a bit how microsecond will be exhausted? Is the transmission can be processed simultaneously in both directions? How many pins are owned by the network and what is the use of each pin? In general, design problems are found here related to the mechanical, electrical and procedural interfaces, and physical media which is under the physical layer. Data Link Layer The main task of the data link layer is as raw data transmission facility and transforms the data to a channel that is free from transmission errors. Before forwarded who work layer, data link layer perform this task by allowing the sender meme cage breaking input data into a number of data frames (usually numbering in the hundreds or thousands of bytes). Then the data link layer transmits these frames in sequence, and process the acknowledgment frames sent back by the recipient. Because the physical layer send and receive bit stream without regard to the meaning or architectural frame, then depending on the data link layer was to create and recognize frame boundaries it. This can be done by affixing a special bit to the beginning and end of the frame. If incidental bit patterns can be found in the data, it is necessary to pay special attention to ensure that the pattern is not incorrectly considered as the boundaries of the frame. The occurrence of noise in the channel can damage the frame. In this case, the data link layer software on the source machine to send back the broken frame. However, transmission of the same frame over and over again can cause duplication of frames. Duplicate frames need to be sent if an acknowledgment frame from the receiver who returned to the sender has been lost. à ¯Ã‚ ¿Ã‚ ½Depending on the layer is to overcome the problems that caused the destruction, loss and duplication of frames. The data link layer provides some service classes for the network layer. This service class can be distinguished in terms of quality and priceà ¯Ã‚ ¿Ã‚ ½.[4] Other problems that arise in the data link layer (and also most of the layers above it) are seeking the smooth process of data transmission from the sender to the recipient a slow speed. Mechanism of regulation of traffic data should allow the sender to know the amount of buffer space owned by the recipient at a certain moment. Often setting flow and error handling is done in an integrated manner. Channel that can send data in both directions also can be problematic. So therefore need to be considered for the data link layer software. Problems that can arise here is that the frames acknowledgement flowing from A to B compete with each other ahead of the flow from B to A. Settlement of the best (piggy backing) could have been used, then we shall discuss it in depth. Broadcast networks have an additional problem in the data link layer. The problem is in terms of controlling access to a shared channel. To fix this you can use a special sub layer of data link layer, called the medium acc ess sub layer. Network Layer Network layer serves to control operation of the subnet. Important design problem is how to determine the route packets from source to destination. Route can be based on static tables are linked to network. Route can also be determined at the beginning of a conversation such as a terminal session. Finally, the route can also be very dynamic; it can be different for each package. Therefore, the delivery route of a packet depends on network load at that time. If at the same time in a subnet there are too many packets, then there is the possibility of the packages arrive at the same time. This can lead to bottlenecks. Congestion control as it is also the task of the network layer. Because the sub net operators expect the good fortune of his job duties. There is often some accounting function built at the network layer. To make billing information, at least the software should calculate the number of packets or characters or bits that are sent by each customer. Accounting becomes more co mplicated, when a packet crosses a country that has a different rate. The move packets from one network to another can also cause problems that are not small. Addressing mode used by a network can be different from the methods used by other network. A network may be unable to receive the package at all because the packet size is too big. Protocol was be different, as well as others. Network layer has been given the task to solve all these problems, allowing different networks interconnected to each other. Transport Layer The basic function is the transport layer receives data from the session layer, split the data into pieces smaller if necessary, forwards the data to the network layer, and ensure that all pieces of data can arrive at the other side correctly. Moreover, all this must be done efficiently, and aims to protect the upper layers of the changes in hardware technology that can not be avoided. Under normal circumstances, the transport layer makes the network connection is different for each transport connection which is required by the session layer. When the transport connection requires a high throughput, then the transport layer can make a lot of network connections. Transport layer divide sending data to a number of networks to increase throughput. On the other hand, if the manufacture or maintenance of the network connection is quite expensive, transport layer can combine multiple transport connections to the same network connection. This is done to make this merger is not seen by the s ession layer. Transport layer also determines the type of service for the session layer, and in turn the type of service for users of the network. Type of the most popular transport layer is a channel error-free point to point that forward messages or bytes in accordance with the order delivery. However, there are also other types of transport services. The services are transport isolated messages that do not guarantee order of delivery, and broadcast messages to a number of purposes. Type of service determined when the connection starts. Transport layer is a layer end to end in fact, from source to destination. In other words, a program on the source machine to bring the conversation with the same program on the target machine. In the lower layers, there are protocols between the two machines and other machines that are close by. Protocol is not located in the outer or the source machines outer purpose machine, which may be separated by a router. The differences between layers 1 to 3 are intertwined and layer 4 to 7 are end to end. This can be explained as shown in Figure 1-1. In addition to merging multiple streams of messages into a single channel, transport layer must be careful in defining and deciding on the network connection. This process requires a naming mechanism, so that a process on a machine has a way to explain with whom the machine wants to talk. Also there should be a mechanism to regulate the flow of information, so that the flow of information from a fast host does not overwhelm a slow host. Such mechanism is called flow control and plays an important role in the transport layer (also in other layers). Flow control between hosts with different hosts by controlling the flow of the router with the router. Well find out later that the same principles used for both types of the control. Session Layer Session layer allows users to establish sessions with other users. A session in addition allows ordinary data transport, as did the transport layer, also provides special services for specific applications. A session is used to allow one user logs into a remote timesharing system or to move files from one machine to another to machine. A session layer service is to implement the dialogue control. Sessions can allow traffic to move in two directions at one time or only in one direction only. If at one time in traffic only in one direction only analogous to a single railway line, the session layer helps to determine who is entitled to use the channels turn at an instant. Service sessions are described as token management. For some protocols, it is important to ensure that both parties concerned do not perform surgery at the same time. To regulate this activity, the session layer provides tokens that can turn. Only a party that holds the token is allowed performs critical operations. Another session is a synchronization service. Take for example that can occur when trying to transfer files that lasted 2 hours from one machine to another machine with the possibility of having an interval of 1 hour between the two crashes that can occur. After each transfer is canceled, the transfer may need to be repeated again from scratch, and may experience another failure. To reduce the possibility of this problem, the session layer can insert a specific sign to the flow of data. Therefore, if a crash, only the data that is after the sign is to be transferred back. Presentation Layer Presentation layer performs certain functions that are required to ensure the discovery of a common solution for certain problems. Presentation Layer does not allow users to solve their own problems. Unlike the layers underneath are only moving the bits from one place to another place, presentation layer attention to syntax and semantics of information transmitted. One example is the encoding of data presentation service. Most users do not move a random string of binary bits. The users exchange data just as the name, date, amount of money, and bills. The items are expressed in the form of a string of characters, integer numbers, floating point numbers, a data structure formed from some simpler items. There is a difference between one computer to another computer in a given code to declare a string of characters (for example, ASCII and Unicode), integer (for example, complement and complement one two), and so forth. To allow the two computers that have different presentation to commun icate, data structures to be exchanged can be expressed by means of abstract, in accordance with standard encoding to be used on line. Presentation layer-data set and convert this abstract structure of representation that is used on a computer into a network standard representation, and vice versa. Application Layer Application layer consists of a variety of protocols. For example there are hundreds of incompatible terminal types in the entire world. Take the situation where full-screen editor is expected to work on a network with a variety of terminals, which each have different screen layouts, have a way different sequence of keystrokes for the insertion and deletion of text, move the sensor and so forth. One way to overcome such problems in data is to define an abstract network virtual terminal, so editors and other programs can be written for each corresponding. To handle each terminal type, one part of the software must be written to map the network virtual terminal functions to the actual terminal. For example, when moving the cursor editor virtual terminal into the left corner of the screen, the software should issue the appropriate command sequence to achieve the cursor. All virtual terminal software is in the application layer. Another application layer function is file transfer. File systems from one another have different naming conventions, how to express the lines of text are different, and so forth. Transfer files from a system different to other systems that require treatment to overcome the lack of this compatible. The task is also a job application layer, such as electronic mail, remote job entry, directory lookup, and various general purpose facilities and other special purpose facilities. CONCLUSION The process of sending a data to be sent to the recipient. Sender processes submitting data to the application layer, which then add the user application header, the AH (which may also be empty), the front end and submit the results to the presentation layer. Presentation layer can form these data in various ways and may just add a header at the front end, which is given by the session layer. It is important to remember that the presentation layer is not aware of the data which are marked AH by application layer is the data users really are. The process of granting this header repeated until the data reaches the physical layer, where data will be transmitted to other machines. On these machines, all headers were be removed one by one until reaching the admissions process. Figure1 .3 Examples of how the OSI model used The key here is that although the actual data transmission is each layer is programmed as though the transmission in question took place horizontally. For example, when transport layer delivery get a message from the session layer, transport layer will then affix the transport layer header and sends it to the receiver transport layer. INTRODUCTION Computer networks are a tool, known also as nodes, relating to media liaison. Node may consist of a computer, printer or other device to send and receive data generated by other nodes, nodes in the network. Media Liaison, also known as communication media. On this day, there are various types of networks, including local area network (LAN) and wide area network (WAN). The largest network in the world is the Internet. Edit Development. Network started with a small building, the connection about ten computers and a printer. The technology that exists at the time the computer is connected to limit the number and length of communications cable that can be allowed on the network. In the early nineties the communication cable can be pulled so far about 600 feet to the extension of approximately 30 computers only. This network is suitable for a small organization known as local area network (LAN). LANs typically connect devices in a building or a building. A LAN can be built only with two computers and a printer or can be extended only in one building to include audio and video software. LAN size is limited to a distance of several kilometers only. LAN with data rates from 4 Mbps to 100 Mbps. Network connections from different countries has established the development of LAN to the wide area network (WAN). WAN can be sending data, audio and video at distances up to cover a country or continent or around the world. QUESTION 2 Briefly explain at least four (4) topologies of networks and suggest how we implement these topologies in networking. MAIN BODY Network can be of any of the following three types: Local Area Network: Figure: 2.1 Local Area Network Local Area Network (LAN) is a limited range of geographical barriers such as a laboratory, a school or building. In a typical LAN configuration, one of the computers used as file server file server that functions to keep all the software that controls the network. All computers are connected to the server file known as a workstation. Computer workstation comprising a desktop computer specifications less than the server and also may have software on the disk severity. Cable used to connect the LAN via network card installed on each computer. Metropolitan Area Network: Figure : 2.2 Metropolitan Area Network Town Area Network (MAN) covers a wider geographical area as a region or city. Widespread area network connecting a number of Local Area Network in a place to enable sharing of information carried. Universities and government agencies Wide spread Area Network to communicate with the other communities and private industries. One example is the MAN MIND Network, located in Pasco County, Florida which enables communication between the Central Pasco Media Center Main Frame using a telephone line, coaxial cable, and wireless communication providers. Wide Area Network: Figure : 2.3 Wide Area Network Widespread Area Network (WAN) covers a wider area as a state, nation and world. To create a WAN requires systems across the sea or the use of microwave or satellite. Use WAN enables communication between the states can be implemented quickly. Configuring the WAN is complex and requires a hardware multiplexing multiplexer for LAN and MAN links for access to a comprehensive communications network such as the Internet. Network Topology: Figure : 3.1 Network Topology à ¯Ã‚ ¿Ã‚ ½A computer network system using communication line that connects computers to each otherà ¯Ã‚ ¿Ã‚ ½.[5] There are various methods that can be used for the communication and is known as topology. Topology can be considered as a virtual shape or structure of a network. This shape actually does not correspond to the actual physical design of the devices on the computer network. The computers on the home network can be arranged in a circle shape but it does not necessarily mean that it presents a ring topology. There are few types of topologies for computer networks, namely: Star Network Topology Figure :3.1.1 Star Network Topology Star topology is a network where all computers or other devices connected to the central distribution system, known as the Hub or Switch. Hub or Switch is responsible for managing the computer network. All messages or data that is sent to a central control hub for avoid collisions from occurring. There are two operations that used by the hub or switch that is operating broadcast and the operations of the transition switching. à ¯Ã‚ ¿Ã‚ ½Distribution operations, hub or switch will make the delivery of data received from one station to all the routes connecting them. In transition operations, the hub or switch will save the data received and sends the data through a receiving stationà ¯Ã‚ ¿Ã‚ ½.[3] Each node can be connected to the network and can be removed at any time without affecting the whole system of directly by. Furthermore, if one node does not work, it will not affect other computer networks. Any damage to the connection between the hub nodes will not affect the system as a whole, but if the damage occurred on the hub, the entire system will also be affected. The main weakness of this topology is that it requires a fairly high cost in view of all systems connected to it computers, scanners, printers, etc. requires its own cable. Ring Network Topology Figure :3.1.2 Ring Network Topology In local area networks where the ring topology is used, each computer is connected to the network in a closed loop or ring. The Messages or data to be transferred in order according to the same path in the same ring. Network technology was first used by IBM systems with Type I in the category of cable shielded Twisted Pair STP. Each data node will be checked by delivery location. If not the same node strike, it will be submitted to the next node and this will continue until the delivery address the same node strike. à ¯Ã‚ ¿Ã‚ ½As the data is transferred by the same route as the sequence of the potential for violations of data that appears to be similar to the network and can be removed at any time without affecting the whole system of directly byà ¯Ã‚ ¿Ã‚ ½.[6] However, one problem that arises is if a node fails, the entire network will probably also be affected. Arrangement of nodes in this topology is almost the same physically as star topology; only a logical was a ring. The attachment is required in this topology is called Multi Station Access Unit (MSAU). MSAU is installed in a ring-shaped network where it is more than one unit. If only one unit only used the physical topology is similar to the star connection. Bus Network Topology Figure :3.1.3 Bus Network Topology Bus topology, are also known as the Ethernet using a line length where each node in relation to him. Data will be sent by each node in the hope that it does not collide with data transmitted from other nodes. If it happens, the node will try again until successful. Weakness of the bus topology is in terms of maintenance. It is quite difficult to maintain in view of the connection is in the form of a series. In the event of damage to any line at any node, it will cause the entire system will not work. In addition to accurately locate points or nodes those are damaged. Each node can be connected to the network and can be removed at any time without affecting the whole system directly. Furthermore, if one node does not work nor does it affect other computer networks. The other advantage is there in this topology is that it uses a single cable and requires no additional hardware to build the network. But it does not require a very high cost for maintenance purposes. Tree Network Topology Figure :3.1.4 Tree Network Topology The tree topology is essentially a hybrid of the bus and star layouts. It is also known as a hierarchical topology and has a central root node that is connected to one or more nodes of a lower hierarchy. à ¯Ã‚ ¿Ã‚ ½In a symmetrical hierarchy, each node in the network has a specific fixed number of nodes connected to those at a lower levelà ¯Ã‚ ¿Ã‚ ½.[3] Apart from these basic types of network topologies, there are hybrid network topologies, which are composed of a combination of two or more basic topologies. These network mappings aim at harnessing the advantages of each of the basic topologies used in them. Network topologies are the physical arrangements of network nodes and wires. What is interesting is that the inanimate nodes and wires turn live for the transmission of information. Mesh Network Topology Figure :3.1.5 Mesh Network Topology In a full mesh network, each network node is connected to every other node in the network. Due to this arrangement of nodes, it becomes possible for a simultaneous transmission of signals from one node to several other nodes. In a partially connected mesh network, only some of the network nodes are connected to more than one node. à ¯Ã‚ ¿Ã‚ ½This is beneficial over a fully connected mesh in terms of redundancy caused by the point-to-point links between all the nodesà ¯Ã‚ ¿Ã‚ ½.[5] The nodes of a mesh network require possessing some kind of routing logic so that the signals and the data traveling over the network take the shortest path during each of the transmissions. CONCLUSION Topologies are essence of computer networks design. Efficient networks can only be built based on the complete knowledge and understanding of above mentioned topologies. Knowledge of every communication device is of equal importance to help you find the best option for your network requirements. Optimum networks can be built with complete knowledge and understanding of computer network devices and how they are designed, any mistake in choosing inappropriate techniques, device etc can only be the waste of time, resources and efforts. APPENDIX Figure 1.1. OSI Reference Model Application Application Overlay Presentation Session Transport Data Transport Undercoat Network Data Link Physical Table 1.2 Separation of top layer and bottom layer of the OSI model Figure1 .3 Examples of how the OSI model used Figure: 2.1 Local Area Network Figure : 2.2 Metropolitan Area Network Figure : 2.3 Wide Area Network Figure : 3.1 Network Topology Figure :3.1.1 Star Network Topology Figure :3.1.2 Ring Network Topology Figure :3.1.3 Bus Network Topology Figure :3.1.4 Tree Network Topology

Downside of the Excellent American Education System

In the book why they excel, we can see that American education system is good by looking from the result of the progress of technology and economic in this country but why Asian students is better than American students in United states, is it because of our system education is lower than their system education or from the quality of the people?. We can answer this by looking our system education from the success and failure and my experience in here. We all know that American education system is good, as a result we can see it from the invention of many things for example like internet technology or computing system. The success from this education, we can see from the quality of the education, we know that United States is very popular in education, for example so many people from United States can work in out of this country easily after finishing their school. The system of education here is very good, in which studying in this country is very nice because we can study what we want without taking so many general educations. For example when we want to study business Computer information system, we can finish it by 3 years. But other country like Indonesia, we cannot graduate just by 3 years only because so many general educations we have to take there. So it is not efficient to take many General educations because it is not important, anyway we will forget it after we finish school. On the other hand American education has some disadvantages, for example like Asian students can do better than American students, it is really crazy things, because Asian students have to study the language first before they study here. But in fact Asian students are better. We can see why Asian students are better because of 2 sides, in which it is intern side and extern side. Intern side is for example like the motivation of their parents, and Confucianism. And extern side is the quality of their high school in Asian. So that is why Asian Students do not feel difficulties in studying here. For example like in Singapore in which the standard of the high school there is the highest in this world for math, so the students from Singapore who want to continue their study here they will not feel any difficulties because the level of difficulties in almost all subject is lower than in Singapore. In my experience, I can decide that American education is very good, because we just take like 3 years to take bachelor, and after that we can work to look for money, and it is really good thing, but American system has failure also, for example in my math class, all Asian students can get A, we can see it how bad the quality of high school here, because almost all students have to study new things in university, but in fact all Asian students have already studied that thing in their high school in Asia. Therefore my idea about the success and failure from our experience in studying here is that we have to change the system of the American high school here, because the quality is reallylow, for example like we have to give more subject to all high school students so they can be more competitive with Asian students.

The Golden Lily Chapter 16

I WASTED NO TIME in getting the group together. This was big. I still didn't know the level of danger we were facing, but I refused to take any chances. I chose Clarence's house as a meeting spot, seeing as the hunters didn't know about it yet. It still made me nervous. I would've been nervous even if we'd been meeting in an Alchemist bunker. And apparently, â€Å"hunters† wasn't even the right term. According to their low-quality pamphlet, they called themselves â€Å"The Warriors of Light.† I wasn't sure they deserved that fancy title, especially since in their mission statement, they spelled â€Å"abyss† as â€Å"abiss.† The pamphlet was really very sparse, simply stating that there was an evil walking among humanity and that the Warriors were the force there to destroy it. They urged their fellow humans to be ready and stay pure. None of the vampires were mentioned by name, for which I was glad. The pamphlet also didn't mention much about any of the shared history they claimed to have with the Alchemists. Before we went to Clarence's, Eddie scoured Latte for any sort of tracking device. The very idea creeped me out, the same way being watched at Adrian's did. There was a feeling of violation to it all. It was only my lack of faith in their technology that made me feel somewhat better. â€Å"It seems unlikely they'd be that advanced,† I told Eddie, as he wiggled under the car. â€Å"I mean, that pamphlet looked like it had been made on a 1980s copy machine. I don't know if that's because they've had the pamphlets sitting around that long or if that's the actual machine they still use†¦ but regardless, they don't scream high tech to me.† â€Å"Maybe,† he agreed, voice slightly muffled. â€Å"But we can't take any chances. We don't know what they're capable of. And for all we know, they're trying to hook up with the Alchemists to score technology.† Chills ran through me. It was an outrageous thought: that the Alchemists and this violent fringe group could be related. It had been crazy when Adrian and I had speculated about it and was hard to accept even in the face of mounting evidence. At least now I had enough information to take to my superiors without being ridiculed. Even though I'd never heard of hunters like this, it seemed plausible that somewhere, at some point, they'd tried to connect with my organization. Hopefully someone in the Alchemists could help. Eddie scooted out from under Latte. â€Å"You're clean. Let's head out.† Jill and Angeline were waiting nearby, both tense and anxious. Jill gave Eddie an admiring smile. â€Å"I didn't know you knew how to do any of this. I never would have even thought about it.† He wiped sweat off his forehead. â€Å"You thought guardian training was all about hitting and kicking?† She flushed. â€Å"Pretty much, yeah.† â€Å"Can you tell me about some of this stuff sometime?† asked Angeline. â€Å"Seems like I should know it.† â€Å"Sure,† said Eddie, sounding like he meant it. She beamed. He'd been much easier around her ever since her attitude had become more serious and restrained. I think some of that good behavior had played a role in me getting permission for her to join us tonight. She was still technically on suspension, but I'd managed to get a special exemption on the grounds of our family's so-called religion. I'd used a similar excuse when Jill had been suspended last month, in order to take her to feedings. Even still, we were on very strict orders with Angeline tonight. She couldn't be out for more than two hours, and the price was adding an extra day of suspension to her sentence. We took an abnormal route to Clarence's, and Eddie watched behind us carefully, looking for any signs of pursuit. He tried to explain some of the things I needed to watch for when I was on my own. I was so nervous, I hardly heard. After a tense ride, we made it safely to Clarence's. There, we found Adrian already waiting for us. Dimitri had apparently been downtown earlier and picked Adrian up – no doubt taking all the same precautions Eddie had for travel. I'd given Eddie and Dimitri some of the info on the hunters, but everyone else required a more thorough explanation. We gathered in our usual spot, the formal living room, and Dimitri paced around the room, bracing for an attack at any moment. Clarence looked on from his chair with that typical distracted gaze. When I held up the pamphlet, however, he came to life. â€Å"That's them!† he cried. I thought he might actually spring up from the chair and rip the pamphlet from my hands. â€Å"Those are their symbols!† Most of the same alchemical symbols that had been on the sword were strewn across the pamphlet's front. â€Å"That circle. I remember that circle.† â€Å"The gold symbol,† I confirmed. â€Å"Or, I guess in their case, the sun symbol since they're so obsessed with light and dark.† Clarence looked around frantically. â€Å"They're back! We have to get out of here. I came to this city to escape them, but they've found me. We have no time. Where's Dorothy? Where's Lee? I must pack!† â€Å"Mr. Donahue,† I said, in as a gentle a tone as I could manage, â€Å"they don't know you're here. You're safe.† I didn't know if I believed that and hoped I was convincing. â€Å"She's right,† said Dimitri. â€Å"And even if they did, you know I wouldn't let them hurt you.† There was such confidence and strength in the way Dimitri spoke that I had a feeling that we'd believe him even if a group of Strigoi were invading, and he said, â€Å"It's fine, you're safe.† â€Å"If what you're saying is true,† said Sonya, â€Å"I'm the one that's in danger.† She seemed much calmer than I would be in that situation. â€Å"They're not going to hurt you either,† said Dimitri sharply. â€Å"Especially if you don't leave this house.† â€Å"The research – † she began. † – is nothing compared to your safety,† he finished. There was a look in his eyes that said he would tolerate no arguments. â€Å"You need to get back to Court. You were planning on it anyway. Just make the trip early.† Sonya didn't look happy about that. â€Å"So I leave the rest of you in danger?† â€Å"Maybe we aren't,† said Eddie, though the tension in his body said otherwise. â€Å"From what Sydney said – and their mini-manifesto – their focus seems to be Strigoi, not Moroi.† He glanced over at Jill. â€Å"Not that we can let our guard down. If they've mistaken Sonya for a Strigoi, who knows what other craziness they might do? Don't worry. I won't let them near you.† Jill looked ready to swoon. â€Å"That's a good idea,† I said. â€Å"They still think the Moroi are a threat but not as much as the Strigoi.† â€Å"Kind of like the Alchemists,† said Adrian. He was sitting in a corner armchair and had been quiet this whole time. I hadn't seen him since the night of the dance or had any communication with him, which was odd. Even when he wasn't sending me pathetic e-mails about the experiments, he almost always had some witty quip to pass along. â€Å"True,† I admitted, with a smile. â€Å"But we're not trying to kill any of you. Not even Strigoi.† â€Å"And there's the problem,† said Dimitri. â€Å"These warriors are convinced Sonya used to be a Strigoi and is using some trick to disguise herself.† â€Å"Maybe they have some tracking or inventory system,† Sonya mused. â€Å"They keep tabs on various Strigoi in the country and then try to hunt them down.† â€Å"And yet they didn't know about you,† I pointed out to Dimitri. His face stayed neutral, but I knew it was hard for him to be reminded of his Strigoi days. â€Å"And from what I know†¦ you were much more of a, um, notable figure than Sonya.† He'd essentially been a Strigoi mobster. â€Å"So, if you're off their radar, they probably don't have an international presence – or at least not a Russian one.† Angeline leaned forward, hands clasped, and regarded Clarence with a smile sweet enough to justify her name. â€Å"How do you know about them? How did you first run into them?† At first, he looked too terrified to answer, but I think her kindly attitude soothed him. â€Å"Well, they killed my niece, of course.† We all knew Lee had killed Clarence's niece, but the old man didn't believe this any more than he believed Lee was dead. â€Å"Did you see them when they did it?† asked Angeline. â€Å"Did you ever see them at all?† â€Å"Not when Tamara died, no,† he admitted. His eyes got a faraway look, as though he were staring straight into the past. â€Å"But I knew what signs to look for. I'd run into them before that, you see. Back when I was living in Santa Cruz. They like California, you know. And the Southwest. Goes back to their sun fixation.† â€Å"What happened in Santa Cruz?† asked Dimitri. â€Å"A group of their young ones began stalking me. Trying to kill me.† The rest of us exchanged glances. â€Å"So they do go after Moroi,† said Eddie. He actually moved closer to Jill. Clarence shook his head. â€Å"Not usually. From what Marcus told me, they prefer Strigoi. These were young, undisciplined members of their order going off on their own, without the knowledge of their superiors. I assume it was the same type who killed Tamara.† â€Å"Who's Marcus?† I asked. â€Å"Marcus Finch. He saved me from them a few years ago. Fended them off during an attack and later got in touch with their order to keep those ruffians away from me.† Clarence shivered at the memory. â€Å"Not that I stayed around after that. I took Lee and left. That was when we moved to Los Angeles for a while.† â€Å"This Marcus,† I said. â€Å"Was he a guardian?† â€Å"A human. He was about your age then. He knew all about the hunters.† â€Å"I suppose he would if he got in touch with them,† Dimitri speculated. â€Å"But he must be friendly to Moroi if he helped you?† â€Å"Oh, yes,† said Clarence. â€Å"Very much so.† Dimitri looked over at me. â€Å"Do you think – â€Å" â€Å"Yes,† I said, guessing his question. â€Å"I'll see if we can find this Marcus guy. It'd be nice to get a source of info that's not one of these crazy warriors. I'm also going to report on all of this, actually.† â€Å"Me too,† said Dimitri. Although Clarence wasn't the expert on the hunters that this mysterious Marcus was, the old Moroi still had a surprising amount of info to share – info none of us had wanted to hear before. He verified what we'd already deduced, about the hunters' â€Å"devotion to the light.† The group's focus was Strigoi (for now), and all of their hunts were carefully planned and organized. They had a ritualized set of behaviors, particularly in regard to their younger members – which was why the rogue group harassing Clarence had been stopped. From what Clarence had gathered, the group was quite tough on their new recruits, emphasizing discipline and excellence. With the clock ticking down on Angeline's reprieve, we needed to wrap things up shortly thereafter. I was also in charge of taking Adrian home, since we figured it'd be best to eliminate any chance of Dimitri being followed back to Clarence's. Besides, I could tell Dimitri was anxious to begin putting certain things in motion. He wanted to finalize Sonya's departure and also confer with the guardians – in case Jill needed to be removed. Her face reflected what I felt about that possible outcome. We'd both become attached to Amberwood. While he was giving some last-minute instructions to Eddie, I pulled Sonya aside for a quiet word. â€Å"I†¦ I've been thinking about something,† I told her. She studied me carefully, probably reading my aura and other body language. â€Å"What is it?† she asked. â€Å"If you want†¦ if you really want it, you can have some of my blood.† It was a huge, huge admission. Was it something I wanted to do? No. Absolutely not. I still had the same instinctive fears about giving my blood to Moroi, even for scientific purposes. And yet, yesterday's events – and even the alley attack – had begun making me re-analyze my worldview. Vampires weren't the only monsters out there. They were hardly monsters at all, especially next to these vampire hunters. How could I judge the enemy on race? I was being reminded more and more that humans were just as capable as vampires of evil – and that vampires were capable of good. It was actions that mattered, and Sonya and Dimitri's were noble ones. They were fighting to destroy the ultimate evil of all, and as squeamish as I felt about giving my blood, I knew the right thing was to help them. Sonya knew what a sacrifice this was for me. Her face stayed calm – no whoops of joy – and she nodded solemnly. â€Å"I have my collection kit here. I can take a sample before you leave, if you're sure.† So soon? Well, why not. It was best to get it over with – especially if Sonya would be leaving town soon anyway. We did it in the kitchen, which seemed slightly more sanitary than the living room. Sonya was no doctor, but whatever training she'd had, it was right in line with what I'd observed when getting physicals. Antiseptic, gloves, a new syringe. All the right procedures were followed, and after a quick poke of the needle, she had my blood sample. â€Å"Thank you, Sydney,† she said, handing me a plastic bandage. â€Å"I know how difficult this must have been for you. Believe me, this could really help us.† â€Å"I want to help,† I told her. â€Å"I really do.† She smiled. â€Å"I know. And we need all the help we can get. After being one of them†¦Ã¢â‚¬  Her smile faded. â€Å"Well, I believe more than ever that their evil needs to be stopped. You might be the key.† For one second, her words inspired me – that I might somehow play a greater role in the fight against evil and possibly even stop it. Immediately, that thought was replaced by my old panic. No. No. I wasn't special. I didn't want to be. I would make a good faith effort to help, but surely nothing would come of it. I returned to fetch the others. Adrian and Jill were having some earnest conversation in the corner. Eddie and Angeline were also talking, and I overheard her say, â€Å"I'll stay with Jill more at school, just to be safe. We can't have her be part of some accident or mistaken identity.† Eddie nodded and looked impressed that she'd suggested it. â€Å"Agreed.† Amazing, I thought. I left soon with my carpool and swung by downtown to drop Adrian off. As I pulled up in front of his building, I saw something that made my jaw drop. Awe and disbelief rolled through me. In what was probably the most ungraceful parking job I'd ever done in my life, I brought Latte to an abrupt stop and was out of the car the second I pulled my keys from the ignition. The others followed moments later. â€Å"What,† I breathed. â€Å"Is that?† â€Å"Oh,† said Adrian casually. â€Å"That's my new car.† I took a few steps forward and then stopped, afraid to approach it in the same way someone hesitated before royalty. â€Å"It's a 1967 Ford Mustang convertible,† I said, knowing my eyes were probably bugging out of my face. I began walking around it. â€Å"The year they did a major overhaul and increased the size to keep up with other high-powered competition. See? It's the first model with the concave tail lights but the last to have the Ford block lettering up front until 1974.† â€Å"What in the world is that color?† asked Eddie, not sounding impressed at all. â€Å"Springtime Yellow,† Adrian and I said in unison. â€Å"I would've guessed Lemon Chiffon,† said Eddie. â€Å"Maybe you can get it repainted.† â€Å"No!† I exclaimed. I tossed my purse over onto the grass and carefully touched the car's side. Brayden's beautiful new Mustang suddenly seemed so ordinary. â€Å"It's been touched up, obviously, but this is a classic color. Which engine code is this? C, right?† â€Å"Um†¦ not sure,† said Adrian. â€Å"I know it's got a V-8 engine.† â€Å"Of course it does,† I said. It was hard not to roll my eyes. â€Å"A 289. I want to know what the horsepower is.† â€Å"It's probably in the paperwork,† Adrian said lamely. It was at that moment that I really processed Adrian's earlier words. I looked up at him, knowing my face must be filled with disbelief. â€Å"This is really your car?† â€Å"Yup,† he said. â€Å"I told you. The old man spotted me the money for one.† â€Å"And you got this one?† I peered in through the window. â€Å"Nice. Black interior, manual transmission.† â€Å"Yeah,† said Adrian, a note of unease in his voice. â€Å"That's the problem.† I glanced back. â€Å"What is? The black is great. And the leather's condition is fantastic. So is the rest of the car.† â€Å"No, not the interior. The transmission. I can't drive a stick.† I froze. â€Å"You can't drive a stick?† â€Å"Neither can I,† said Jill. â€Å"You don't have a license,† I reminded her. Although, my mother had taught me to drive before I had a license – both automatic and manual transmission. I knew I shouldn't be surprised the stick was a lost art, as savage as such a lack seemed to me. That paled, of course, in comparison to the other obvious problem. â€Å"Why on earth would you buy a car like this if you can't drive a stick? There are dozens of cars – new cars – that have automatic transmission. It'd be a million times easier.† Adrian shrugged. â€Å"I like the color. It matches my living room.† Eddie snorted. â€Å"But you can't drive it,† I pointed out. â€Å"I figure it can't be that hard.† Adrian sounded remarkably unconcerned about what I found blasphemous. â€Å"I'll just practice taking it around the block a few times and figure it out.† I couldn't believe what I was hearing. â€Å"What? Are you out of your mind? You'll ruin it if you don't know what you're doing!† â€Å"What else am I supposed to do?† he asked. â€Å"Are you going to teach me?† I turned back to the beautiful Mustang. â€Å"Yes,† I said adamantly. â€Å"If that's what it takes to save it from you.† â€Å"I can show you too,† said Eddie. Adrian ignored him and focused on me. â€Å"When we can start?† I ran through my school schedule, knowing I'd have to make talking to the Alchemists about the Warriors of Light my top priority. Then, the obvious hit me. â€Å"Oh. When we see Wolfe this week. We'll take this out there.† â€Å"Is that really to help me?† asked Adrian. â€Å"Or do you just want to drive the car?† â€Å"Both,† I said, not embarrassed to admit it. Angeline's clock at school was ticking, so the rest of us had to leave. I'd driven three blocks away when I realized I'd left my purse on the grass. With a groan, I looped around and returned to his building. My purse was there, but the Mustang was gone. â€Å"Where's the car?† I asked, panicked. â€Å"No one could have stolen it that fast.† â€Å"Oh,† said Jill from the backseat, sounding slightly nervous. â€Å"I saw through the bond. He, um, moved it.† It was handy having the bond as a source of information, but her words made me panic more than if the car actually had been stolen. â€Å"He what?† â€Å"Not far,† she said quickly. â€Å"Just behind the building. This street's got weird overnight parking rules.† I grimaced. â€Å"Well, I'm glad it won't get towed, but he should've had me move it! Even if it's not far, he could ruin the transmission.† â€Å"I'm sure it's fine,† said Jill. There was a strange note to her voice. I didn't respond. Jill was no car expert. None of them were. â€Å"It's like letting a toddler loose in a room full of china,† I muttered. â€Å"What was he thinking? About any of this?† No one had an answer for that. I got us back to Amberwood in time for Angeline's curfew and retreated to the sanity and calm of my room. As soon as I was satisfied my friends were safe and secure for the night, I e-mailed Donna Stanton – a high-up Alchemist whom I'd inexplicably developed a good relationship with – about the hunters and what we'd learned. I even took pictures of the pamphlet and e-mailed those as well. Once that was done, I sat back and tried to think if there was anything else at all I could provide her with that might help. It was only when I'd exhausted all options (and refreshed my inbox a few times to see if she'd responded already) that I finally moved on to homework. As usual, I was pretty much caught up on every assignment – save one. Ms. Terwilliger's. That stupid book was on my desk, staring back at me, daring me to open it. I still had a number of days before her spell was due, time during which I could continue to procrastinate. I was beginning to accept, however, that this assignment wasn't going to go away. Considering how long some of the prep on these took, maybe it'd be best to bite the bullet and get it out of the way. Resolved, I brought the book over to my bed and opened it to the table of contents, scanning some of the spells she'd gone over with me. My stomach twisted at most of them, every instinct telling me how wrong it was to even be attempting these. Magic is for vampires, not humans. I still believed that to be true, but the analytical part of my mind couldn't help but apply some of the defensive spells to various situations. Much like my decision to give blood, recent events had made me look at the world differently. Was magic wrong? Yes. But that blindness spell would have certainly been useful in the alley. Another spell, one that temporarily immobilized people, could've been used if I'd wanted to flee from the hunters at the cafe. Sure, it only lasted thirty seconds, but that was more than enough time for me to have escaped. On and on, I went down the list. They were all so wrong and yet†¦ so useful. If I hadn't seen the fire charm I'd made ignite a Strigoi, I wouldn't have believed any of these were possible. But by all accounts, they were. So much power†¦ the ability to protect myself†¦ Immediately, I rebuked myself for such a thought. I had no need for power. That kind of thinking was what led freaks like Liam to want to be Strigoi. Although†¦ was it really the same? I didn't want immortality. I didn't want to hurt others. I just wanted to protect myself and those I cared about. Wolfe had a lot to teach me, but his preventative techniques wouldn't help if determined vampire hunters cornered Sonya and me again. As time went on, it was becoming clear that the hunters were very determined. I returned to the table of contents, finding several that would be useful and well within my capabilities to make. According to Ms. Terwilliger, someone like me had excellent potential for magic because of inborn talent (which I didn't entirely believe) and the rigorous Alchemist training in measurement and attention to detail. It wasn't difficult to figure out how long it would take me to produce any of these likely candidates. The question was which spell did I make? Which did I have time to make? The answer was eerily simple. I had time to make all of them.

Ricci v. DeStefano a Case of Reverse Discrimination

The  U.S. Supreme Court  case Ricci v. DeStefano made headlines in 2009 because it addressed the controversial issue of  reverse discrimination. The case involved a group of white firefighters who  argued that the city of New Haven, Conn., discriminated against them in 2003 by throwing out a test that they passed at a 50 percent greater rate than their black colleagues. Because performance on the test was the basis for promotion, none of the blacks in the department would have advanced had the city accepted the results. To avoid discriminating against black firefighters, New Haven discarded the test. By making that move, however, the city prevented the white firefighters eligible for promotion from advancing to captain and lieutenant rank. Fast Facts: Ricci v. DeStefano Case Argued: April 22, 2009Decision Issued:  June 2009Petitioner:  Frank Ricci, et alRespondent:  John DeStefano, et alKey Questions: Can a municipality reject results from an otherwise valid civil service exam when the results unintentionally prevent the promotion of minority candidates?Majority Decision: Justices Roberts, Scalia, Kennedy, Thomas, and AlitoDissenting: Justices Souter, Stevens, Ginsburg, and BreyerRuling:  The potential for future litigation does not justify an employer’s reliance on race to the detriment of candidates who have passed the examinations and qualified for promotions. The Case in Favor of the Firefighters Were the white firefighters subjects of racial discrimination? It’s easy to see why one would think so. Take white firefighter Frank Ricci, for example. He scored the sixth highest on the exam out of the 118 test-takers. Seeking advancement to lieutenant, Ricci not only stopped working a second job, he also made flashcards, took practice tests, worked with a study group and participated in mock interviews to pass the oral and written exam, according to the New York Times. A dyslexic, Ricci even paid $1,000 to have someone read textbooks onto audiotapes, the Times reported. Why were Ricci and the other top scorers denied the chance to promote simply because their black and Hispanic colleagues failed to do well on the test? The city of New Haven cites Title VII of the Civil Rights Act of 1964 which prohibits employers from using tests that have a â€Å"disparate impact,† or disproportionately exclude applicants of certain races. If a test does have such an effect, the employer must show that the assessment directly relates to job performance. Counsel for the firefighters argued before the Supreme Court that New Haven could have proven that the test directly related to work duties; instead, the city prematurely declared the exam unfit. During the hearing, Chief Justice John Roberts doubted that New Haven would have chosen to discard the test had the outcomes by race been reversed. â€Å"So, can you assure me that†¦if†¦black applicants†¦scored highest on this test in disproportionate numbers, and the city said†¦we think there should be more whites on the fire department, and so we’re going to throw the test out? The government of the United States would adopt the same position?† Roberts asked. But the New Haven attorney failed to give a direct and coherent response to Roberts’ question, prompting the judge to remark that the city would not have discarded the test had blacks scored well and whites not. If New Haven only did away with the test because it disapproved of the racial makeup of those who excelled on it, the white firefighters in question were no doubt victims of discrimination. Title VII not only prohibits â€Å"disparate impact† but also discrimination based on race in any aspect of employment, including promotion. The Case in Favor of New Haven The city of New Haven asserts that it had no choice but to discard the firefighting test because the exam discriminated against minority applicants. While counsel for the firefighters argues that the test administered was valid, the city’s lawyers say that an analysis of the exam found the test scores had no scientific basis and critical design steps were omitted during its development. Moreover, some of the qualities assessed on the test, such as rote memorization, didn’t directly tie into firefighting in New Haven. So by discarding the test, New Haven didn’t seek to discriminate against whites but to give minority firefighters a test that would not have a disparate impact on them. Why did the city emphasize its efforts to protect black firefighters from discrimination? As Associate Justice Ruth Bader Ginsburg pointed out, traditionally in the U.S, â€Å"fire departments were among the most notorious excluders on the basis of race.† New Haven itself had to pay $500,000 to two black firefighters in 2005 for unfairly promoting their white counterparts over them in the past. Knowing this makes it difficult to accept the white firefighters’ claim that the city prefers minority firefighters to Caucasians. To boot, New Haven substituted the controversial test given in 2003 with other exams that did not have a disparate impact on minority firefighters. The Supreme Courts Ruling What did the court decide? In a 5-4 ruling, it rejected New Haven’s reasoning, arguing that, â€Å"Fear of litigation alone cannot justify an employer’s reliance on race to the detriment of individuals who passed the examinations and qualified for promotions.† Legal analysts predict that the decision could generate a bevy of â€Å"disparate impact† lawsuits, as the court’s ruling makes it harder for employers to discard tests that adversely affect protected groups such as women and minorities. To prevent such lawsuits, employers will have to consider the impact a test may have on protected groups as it is being developed rather than after it has been administered.