What Legitimizes Authority essays

What Legitimizes Authority essays What is authority? In the most basic sense it is the power to command or order. Power is associated with authority. For many, power is the ability to get something done even when there is an opposing force. When asking the question what legitimizes authority it is believed that the consent of the people legitimizes it. When one thinks of authority the government comes into mind. The government holds the authority to execute laws. Jean Jacques Rousseau believes that the government should be based on equality for everyone. Authority can be created through force. Rousseau has established an idea of the General Will. This concept proposes a sort of guideline for communities. Every member of a community has to work to uphold the General Will, so then sovereignty lies within the people of the community and the government. There must be a mutual agreement between authorities and the governed. This means that the governed have agreed to be ruled only so their rulers protect their happiness, property, and rights. Everything must be mutual in society from law to legislator. Rousseau believes that everyone is born free, but all around us are chains. Freedom is a natural condition for human beings. Rousseau explains that our appetites and desires drive us all but at the same time we are also driven to become self- governing and self disciplined people. Authority could be seen as the root of this thought. The philosopher Niccolo Machiavelli believes that it is the seizure of an opportunity that is presented that leads to the position of authority. One must always create a careful and solid plan against his enemy in order to be in authority. In a basic sense one should not hesitate. Authority is created by the powerful. ...

Warm-Up Activities and Fillers for the French Classroom

Warm-Up Activities and Fillers for the French Classroom Most language teachers find that there is a bit of dead time during class. This may occur at the beginning of class, as the students are arriving; at the end of class, as they are thinking about leaving; and right in the middle of class, when transitioning from one lesson to another. During this dead time, the best option is to spend five or ten minutes on a short, interesting activity. Teachers from all over have shared some great ideas for warm-up and filler activities- take a look. Building Sentences Put together the parts of a sentence. Categories List all of the vocabulary in a particular category. Conversations Pair off for short discussions. Meet Your Neighbor Practice greetings and personal details with other students. Music Videos Watch and discuss French music videos. Name Game Learn all of the students names. Quotations Discuss quotations by famous Francophones. Repetitions Have students repeat a list of vocabulary.

Dinosaur bones were placed on this earth by Satan to confuse man Research Paper

Dinosaur bones were placed on this earth by Satan to confuse man regarding the existence of God - Research Paper Example â€Å"Dinosaur bones were placed on this earth by Satan to confuse man regarding the existence of God† According to some Christian sects, dinosaur bones were placed on this earth by Satan to confuse man regarding the existence of God. Jehovah’s Witnesses, Seventh Day Adventists, and Church of Christ’s believers explain their disbelief for the Theory of Evolution and instead believe in the Bible’s account of creation, where God created the world in seven days (Lulu, n.d). They strongly believe this concept of dinosaur bones being placed on earth by Satan because their conceptualization of creation is based on the accounts of the Bible. They point out that the Bible does not make mention of dinosaurs; therefore whatever proof there may be that dinosaurs exist is merely the work of Satan and a test of our faith in God (Warren, 1995). Dinosaur bones are a test of our faith because it leads the people to think that dinosaurs existed a long time ago and that the theory of evolution by Charles Darwin is the accurate account of the birth of our world. Darwin believes that the world was created in stages through his Big Bang Theory where from a single explosion, the world was born (Schwarz, 2002). From such an explosion, the planets and the solar systems came about. With the careful process of time and evolution, more developments in the creation of living things were seen – from the earliest organisms to dinosaurs, then on to mammals and finally to human beings (Schwarz, 2002). These Christian groups however oppose the idea that man evolved from primates and they point out that the missing link has never been discovered (Timmons, 1991). Therefore the idea that man evolved from primates is an inaccurate theory according to these religious groups. Instead, they believe that God created man in seven days. On the first day, God created light. On the second day, he divided the sky and the waters below. On the third day, he gathered the wat ers and the lands together in separate places. On the fourth day, he created the stars and the heavenly planets. On the fifth day, he created the living creatures of the skies and the seas. On the sixth day, he then created the creatures of the lands, including man. And on the seventh day, he rested (Somers and Christmayer, 2004). As can be seen from the account of creation, dinosaurs have not been created by God. Therefore, they do not and have never existed. These dinosaurs are therefore a product of Satan and a test of our faith in God and his creation of our world. In believing the accounts in the Bible, we are therefore led to believe that the accounts in the Bible are a lie and that God does not even exist. Those who believe in this concept of dinosaur bones being the work of Satan, also point out how the different scientific theories contradict their faith (Warren, 1995). One of these theories is that Satan uses such dinosaurs in order to confuse young Christians about their faith and to turn their faith away from God. When these young Christians go to school and learn about these dinosaurs, they also eventually turn away from God and from the teachings of the Bible (Warren, 1995). Some Christians believe that the dinosaurs are not part of God’s creation because man cannot coexist with these creatures. In the end, man would end up being eaten by these dinosaurs. It is therefore difficult to conceptualize the idea of these dinosaurs actually roaming our earth (Trussville, 2008). Their existence has mostly been proven through fossils and not much else. Proof of their existence beyond the realm of such fossils is impossible to place in a firm footing of believability. The best conclusion which can therefore be drawn is to disbelieve the existence of dinosaurs and consider them as works of Satan. For those who have a strong faith in God and the teachings of the Bible, it would be easier for them to believe that dinosaurs never existed even with proof to the contrary (Trussville, 2008). Instead, the crucial belief is for the support in God’

Analyzing the uses of scheduling methods in IT project management Coursework

Analyzing the uses of scheduling methods in IT project management - Coursework Example The data that I will use in this research will be collected from notes and documentation of projects that has been done before. I will particularly make use of planning processes of various projects so that I get to know what is required of a project. I preferred internet databases that would exploit electronic links like; Springer Link, Emerald Management Extra, Sweets Wise Online content and Ulrich. These databases provided a lot of information on applied sciences access to abstracts, full-text versions of articles that have been published in electronic books and project management journals. I found these sources quite intriguing as they enabled wide access of full text reviews, case studies and publications to a greater extent. To obtain information, I logged on the four links mentioned above and absolutely found variety of details on project management. I aimed at reviewing the importance of scheduling in any project undertaking but most exciting was not the relationship between scheduling with traditional engineering and manufacturing projects but relating scheduling concept to the recent IT projects in this instance cloud computing. I therefore found a broad relationship between scheduling and cloud computing, inferring that scheduling is the most preferred mode of ensuring all projects have successful implementation and completion. In a nutshell, the entire search exercise was informative and exciting upon discovering that numerous studies have been made and documented in systematic and logical order in the tune of employing project management tools as Critical Path and Gantt charts. This ordering method enabled me to mark and continue reading the files in phases. My study entailed... This study looks into scheduling is a critical aspect of IT project management in implementation of all level projects. Indeed, the articles and journals highlighted above methods that have been discovered and practically used to achieve and attain project goals. The importance of scheduling is synchronous to the anticipation of IT project managers in effectiveness of information technology. Critically speaking, scheduling and efficiency of IT projects is an practical element in information age. The whole safety boundary that was previously created in to each project is given identity the critical chain optimizing. The total project time period is always reduced when the safety margin is there in every individual activity. But in case of any withdrawal and only one critical activity go beyond the estimated length, the finishing date for the whole project not met. There exist important evidences in this studies that many IT project managers use scheduling and a method to effectively i mplement projects and enable them to run into completion. In a research project done by Dayal, Zachariah & Rajpal the findings indicates that scheduling through network diagrams requires creating a line of balance in development of project plan in which various techniques can be used to implement the planning and control technique for manufacturing and processing that were improvised. This technique is unique in that it identifies and notes the resources needed for each phase and hence the succeeding phase is not affected therefore the goal outcome is attained.

Fundamental Concepts Of Ethernet Technology Information Technology Essay

Fundamental Concepts Of Ethernet Technology Information Technology Essay In this module, we will discuss the fundamental concepts of networking, Ethernet technology, and data transmission in Ethernet networks. Module Objectives At the end of this module, you will be able to: Explain the seven network layers as defined by the Open Systems Interconnection (OSI) Reference model Describe, at a high level, the history of Ethernet List physical layer characteristics of Ethernet Explain the difference between half-duplex and full-duplex transmission in an Ethernet network Describe the structure of an Ethernet frame Explain how networks can be extended and segmented using various Ethernet devices, including hubs and switches Describe how frames are forwarded in an Ethernet network Explain, at a high level, how Virtual Local Area Networks (VLANs) function Network Fundamentals This section provides a brief overview of Local Area Network (LAN) technology. We will discuss LAN architecture from a functional perspective. A network is commonly divided into seven functional layers referred to as the OSI Reference model. In addition, we will briefly discuss the use of addressing in LANs. Instructor Note Point out that this section only touches briefly on LAN concepts, and students may want to explore LAN technology in more depth on their own. Network Layers A complete LAN implementation involves a number of functions that, in combination, enable devices to communicate over a network. To understand how Ethernet fits into this overall set of functions, we can use the OSI Reference model. The OSI Reference model was developed in 1984 by the International Organization for Standardization (ISO). Instructor Note You can introduce the discussion of the OSI Reference model by comparing analysis of the model to peeling an onion. Shown in Figure 1-1, the OSI Reference model defines seven functional layers that process data when data is transmitted over a network. When devices communicate over a network, data travels through some or all of the seven functional layers. The figure shows data being transmitted from Station A, the source, to Station B, the destination. The transmission begins at the Application layer. As data (referred to as the payload) is transmitted by Station A down through the layers, each layer adds its overhead information to the data from the layer above. (The process of packaging layer-specific overhead with the payload is referred to as encapsulation discussed later in this course.) Upon reaching the Physical layer, the data is placed on the physical media for transmission. The receiving device reverses the process, unpackaging the contents layer by layer, thus allowing each layer to effectively communicate with its peer layer. Ethernet operates at Layer 2, the Data Link layer. Using Figure 1-1 as a reference, we will briefly discuss what occurs at each layer. Figure 1-1: The OSI Reference Model Application Layer The Application layer, Layer 7 (L7), is responsible for interacting with the software applications that send data to another device. These interactions are governed by Application layer protocols, such as Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), and Simple Mail Transfer Protocol (SMTP). Presentation Layer The Presentation layer, Layer 6 (L6), performs data translation, compression, and encryption. Data translation is required when two different types of devices are connected to each other, and both use different ways to represent the data. Compression is required to increase the transmission flow of data. Encryption is required to secure data as it moves to the lower layers of the OSI Reference model. Session Layer The Session layer, Layer 5 (L5), is responsible for creating, maintaining, and terminating communication among devices. A session is a logical link created between two software application processes to enable them to transmit data to each other for a period of time. Logical links are discussed later in this course. Transport Layer The Transport layer, Layer 4 (L4), is responsible for reliable arrival of messages and provides error checking mechanisms and data flow controls. The Transport layer also performs multiplexing to ensure that the data from various applications is transported using the same transmission channel. Multiplexing enables data from several applications to be transmitted onto a single physical link, such as a fiber optic cable. The data flow through the Transport layer is governed by transmission protocols, such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), which are beyond the scope of this course. Network Layer The Network layer, Layer 3 (L3), is responsible for moving data across interconnected networks by comparing the L3 source address with the L3 destination address. The Network layer encapsulates the data received by higher layers to create packets. The word packet is commonly used when referring to data in the Network layer. The Network layer is also responsible for fragmentation and reassembly of packets. Data Link Layer The Data Link layer, Layer 2 (L2), responds to requests sent by the Network layer and sends service requests to the Physical layer. The Data Link layer is responsible for defining the physical addressing, establishing logical links among local devices, sequencing of frames, and error detection. The Ethernet frame is a digital data transmission unit on Layer 2. The word frame is commonly used when referring to data in the Data Link layer. The Data Link layer has been subdivided into two sub-layers: Logical Link Control (LLC) and Media Access Control (MAC). LLC, defined in the Institute of Electrical and Electronics Engineers (IEEE) 802.2 specification, manages communications among devices over a link. LLC supports both connection-oriented (physical, ex an Ethernet switch) and connectionless (wireless, ex a wireless router) services. The MAC sub-level manages Ethernet frame assembly and dissembly, failure recovery, as well as access to, and routing for, the physical media. This will be discussed in more detail in this module. Physical Layer The Physical layer, Layer 1 (L1), performs hardware-specific, electrical, and mechanical operations for activating, maintaining, and deactivating the link among communicating network systems. The Physical layer is responsible for transmitting the data as raw bits over the transmission media. Now that we have reviewed the OSI Reference model, lets discuss addressing of network devices. Stations Network devices that operate at the Data Link layer or higher are referred to as stations. Stations are classified as either end stations or intermediate stations. End stations run end-user applications and are the source or final destination of data transmitted over a network. Intermediate stations relay information across the network between end stations. A characteristic of stations is that they are addressable. In the next section, we discuss the specifics of addressing. Addressing Each device in an Ethernet network is assigned an address that is used to connect with other devices in the network. This address is referred to as the MAC address and is typically a permanent address assigned by the device manufacturer. Addressing is used in the network to identify the source station and the destination station or stations of transmitted data. As shown in Figure 1-2, the MAC address consists of 48 bits (6 bytes), typically expressed as colon-separated, hexadecimal pairs. Figure 1-2: MAC Address Structure The MAC address consists of the following: Individual / Group (I/G) Bit: For destination address, if the I/G bit = 0, the destination of the frame is a single station. This is referred to as a unicast address. If the I/G bit = 1, the destination is a group of stations. This is referred to as a multicast address. In source addresses, the I/G bit = 1. Universal / Local (U/L) Bit: The U/L bit identifies whether the MAC address is universally unique (U/L bit = 0) or only unique in the LAN in which it is located. Vendor-assigned MAC addresses are always universally unique. A locally unique MAC address is assigned by the network administrator. Organizationally Unique Identifier (OUI): This typically identifies the network equipment manufacturer. OUIs are assigned to organizations by the IEEE. To locate information on the OUI associated with a manufacturer go to the following website: http://standards.ieee.org/regauth/oui/index.shtml Vendor-Assigned Bits: These bits are assigned by the vendor to uniquely identify a specific device. Following is an example of a MAC address: 00:1B:38:7C:BE:66 Later in this module, we discuss how MAC addresses are used in Ethernet networks. Introduction to Ethernet Ethernet is an internationally-accepted, standardized LAN technology. It is one of the simplest and most cost-effective LAN networking technologies in use today. Ethernet has grown through the development of a set of standards that define how data is transferred among computer networking devices. Although several other networking methods are used to implement LANs, Ethernet remains the most common method in use today. While Ethernet has emerged as the most common LAN technology for a variety of reasons, the primary reasons include the following: Ethernet is less expensive than other networking options. Easy is easy to install and provision the various components. Ethernet is faster and more robust than the other LAN technologies. Ethernet allows for an efficient and flexible network implementation. History of Ethernet Ethernet was invented in 1973 by Bob Metcalfe and David Boggs at the Xerox Palo Alto Research Center (PARC). Ethernet was originally designed as a high-speed LAN technology for connecting Xerox Palo Alto graphical computing systems and high-speed laser printers. In 1979, Xerox ® began work with Digital Equipment Corporation (DEC) and Intel ® to develop a standardized, commercial version of Ethernet. This partnership of DEC, Intel, and Xerox (DIX) developed Ethernet Version 1.0, also known as DIX80. Further refinements resulted in Ethernet Version 2, or DIX82, which is still in use today. Project 802 In 1980, the Institute of Electrical and Electronics Engineers (IEEE) formed Project 802 to create an international standard for LANs. Due to the complexity of the technology and the emergence of competing LAN technologies and physical media, five working groups were initially formed. Each working group developed standards for a particular area of LAN technology. The initial working groups consisted of the following: IEEE 802.1: Overview, Architecture, Internetworking, and Management IEEE 802.2: Logical Link Control IEEE 802.3: Carrier Sense Multiple Access / Collision Detection (CSMA/CD) Media Access Control (MAC) IEEE 802.4: Token Bus MAC and Physical (PHY) IEEE 802.5: Token Ring MAC and PHY Additional working groups have since been added to address other areas of LAN technology. The standards developed by these working groups are discussed as we move through this course. However, lets look at IEEE 802.3, which addresses standards specific to Ethernet. IEEE 802.3 IEEE 802.3 was published in 1985 and is now supported with a series of supplements covering new features and capabilities. Like all IEEE standards, the contents of supplements are added to the standard when it is revised. Now adopted by almost all computer vendors, IEEE 802.3 consists of standards for three basic elements: The physical media (fiber or copper) used to transport Ethernet signals over a network MAC rules that enable devices connected to the same transmission media to share the transmission channel Format of the Ethernet frame, which consists of a standardized set of frame fields We will discuss the transmission media used in Ethernet networks, the MAC rules, and the Ethernet frame later in this module. Instructor Note Tell the class that we will discuss the transmission media used in Ethernet networks, the MAC rules, and the Ethernet frame later in this module. You can briefly explain the differences among LANs, WANs, and MANs to the students. Ethernet Transmission Fundamentals This section covers basic fundamentals of data transmission on Ethernet networks. Specifically, we will cover the following topics: Physical layer characteristics Communication modes Ethernet frames Repeaters and hubs Ethernet bridges and switches Multilayer switches and routers Ethernet Virtual LANs (VLANs) Ethernet beyond the LAN Physical Layer Characteristics Our discussion of physical layer characteristics covers both the physical media over which network communications flow and the rate at which communications occur. In fact, the nomenclature for the various types of Ethernet is based on both of these characteristics. The Ethernet type is referred to in the following format: n-BASE-phy, such as 10BASE-T where: n is the data rate in megabits per second (Mbps). BASE indicates that the media is dedicated to only Ethernet services. phy is a code assigned to a specific type of media. A variety of media and transmission rates are available for Ethernet networks. The major media types used today are: Unshielded Twisted Pair (UTP) copper cable Shielded Twisted Pair (STP) copper cable Fiber optic cables The IEEE 802.3 standard identifies the following types of media for an Ethernet connection: 10BASE2: Defined in IEEE 802.3a, 10BASE2 Ethernet uses thin wire coaxial cable. It allows cable runs of up to 185 meters (607 feet). A maximum of 30 workstations can be supported on a single segment. This Ethernet type is no longer in use for new installations. 10BASE-T: Defined in IEEE 802.3i, 10BASE-T uses UTP copper cable and RJ-45 connectors to connect devices to an Ethernet LAN. The RJ-45 is a very common 8-pin connector. Fast Ethernet: Defined in IEEE 802.3u, Fast Ethernet is used for transmission at a rate of 100 Mbps. It includes 100BASE-TX, which uses UTP copper cable. With this type of cable, each segment can run up to 100 meters (328 feet). Another media option specified in this standard is 100BASE-FX, which uses optical fiber supporting data rates of up to 100 Mbps. Gigabit Ethernet (GbE): Defined in IEEE 802.3z, GbE uses fiber for transmitting Ethernet frames at a rate of 1000 Mbps or 1 Gbps. GbE includes 1000BASE-SX for transmission over Multi-Mode Fiber (MMF), and 1000BASE-LX for transmission over Single-Mode Fiber (SMF). The differences between Multi-Mode and Single-Mode are the physical makeup of the fiber itself and the light source that is normally used multi-mode normally uses an LED while single-mode uses a laser. Multi-mode has limited distance capability when compared to single-mode. 1000BASE-T: Defined in IEEE 802.3ab, 1000BASE-T provides GbE service over twisted pair copper cable. 10 GbE: Defined in IEEE 802.3ae, 10 GbE transmits Ethernet frames at data rates up to 10 Gbps. Communication Modes Ethernet can operate in either of two communication modes, half-duplex or full-duplex. Ethernet MAC establishes procedures that all devices sharing a communication channel must follow. Half-duplex mode is used when devices on a network share a communication channel. Full-duplex mode is used when devices have no contention from other devices on a network connection. Lets discuss each of these modes in more detail. Half-Duplex Mode As shown in Figure 1-3, a device operating in half-duplex mode can send or receive data but cannot do both at the same time. Originally, as specified in the DIX80 standard, Ethernet only supported half-duplex operation. Figure 1-3: Half-Duplex Transmission Half-duplex Ethernet uses the CSMA/CD protocol to control media access in shared media LANs. With CSMA/CD, devices can share media in an orderly way. Devices that contend for shared media on a LAN are members of the same collision domain. In a collision domain, a data collision occurs when two devices on the LAN transmit data at the same time. The CSMA/CD protocol enables recovery from data collisions. With CSMA/CD, a device that has data to transmit performs carrier sense. Carrier sense is the ability of a device to monitor the transmission media for the presence of any data transmission. If the device detects that another device is using the transmission media, the device waits for the transmission to end. When the device detects that the transmission media is not being used, the device starts transmitting data. Figure 1-4 shows how CSMA/CD handles a data collision. When a collision occurs, the transmitting device stops the transmission and sends a jamming signal to all other devices to indicate the collision. After sending the jamming signal, each device waits for a random period of time, with each device generating its own time to wait, and then begins transmitting again. Figure 1-4: CSMA/CD Operation Full-Duplex Mode In the full-duplex communication mode, a device can send and receive data at the same time as shown in Figure 1-5. In this mode, the device must be connected directly to another device using a Point-to-Point (P2P) link that supports independent transmit and receive paths. (P2P is discussed later in this course.) Figure 1-5: Full-Duplex Transmission Full-duplex operation is restricted to links meeting the following criteria: The transmission media must support the simultaneous sending and receiving of data. Twisted pair and fiber cables are capable of supporting full-duplex transmission mode. These include Fast Ethernet, GbE, and 10 GbE transmission media. The connection can be a P2P link connecting only two devices, or multiple devices can be connected to each other through an Ethernet switch. The link between both devices needs to be capable of, and configured for, full-duplex operation. CSMA/CD is not used for full-duplex communications because there is no possibility of a data collision. And, since each device can both send and receive data at the same time, the aggregate throughput of the link is doubled. (Throughput is the amount of data that can be transmitted over a certain period of time.) Ethernet Frames Lets discuss another fundamental aspect of Ethernet transmission the Ethernet frame. The Ethernet frame is used to exchange data between two Data Link layer points via a direct physical or logical link in an Ethernet LAN. The minimum size of an Ethernet frame is 64 bytes. Originally, the maximum size for a standard Ethernet frame was 1518 bytes; however, it is now possible that an Ethernet frame can be as large as 10,000 bytes (referred to as a jumbo frame). As shown in Figure 1-6, an Ethernet frame consists of the following fields: (NOTE: The first two fields are added/stripped at Layer 1 and are not counted as part of the 1518 byte standard frame.) Preamble: This 7-byte field establishes bit synchronization with the sequence of 10101010 in each byte. Start Frame Delimiter: This 1-byte field indicates the start of the frame at the next byte using a bit sequence of 10101011. Destination MAC Address: This field contains the MAC hardware address of the Ethernet frames destination. Source MAC Address: This field contains the MAC hardware address of the device sending the frame. Type / Length: The specific use of this field depends on how the frame was encapsulated. When type-encapsulation is used, the field identifies the nature of the client protocol running above the Ethernet. When using length-encapsulation, this field indicated the number of bytes in the Data field. The IEEE maintains a list of accepted values for this field, the list may be viewed at: http://standards.ieee.org/regauth/ethertype/ Data: This field contains the data or payload that has been sent down from Layer 3 for packaging to Layer 2. Frame Check Sequence (FCS): This 32-bit field is used for checking the Ethernet frame for errors in bit transmission. FCS is also known as Cyclical Redundancy Check (CRC). Figure 1-6: Ethernet Frame Now that we have defined the basic structure of an Ethernet frame, lets see how we can use the destination MAC address to create three different types of Ethernet frames. Unicast Frames An Ethernet frame intended for a single device on the network is a unicast frame. An example is shown in Figure 1-7. In this example, Station A is transmitting an FTP request to a specific FTP server on the network. The destination MAC address in the frames being sent for this request is the MAC address assigned to the FTP server by its manufacturer. Therefore, these frames are unicast frames, only intended specifically for one device on the network, the FTP server. Figure 1-7: Unicast Frame Transmission Multicast Frames Multicast is a mechanism that provides the ability to send frames to a specific group of devices on a network one sender to all who are set to receive. This is done by setting a frames destination MAC address to a multicast address assigned by a higher level protocol or application. However, devices must be enabled to receive frames with this multicast address. An example of multicast frames is shown in Figure 1-8. In this example, the video server is transmitting the same video channel, via an Ethernet switch, to a group of video display devices on the network. The destination MAC address is the multicast address assigned by the video application. The receiving stations are configured to accept Ethernet frames with this multicast address. Figure 1-8: Multicast Frame Transmission Broadcast Frames Broadcasting is a mechanism for sending data in broadcast frames to all the devices in a broadcast domain. A broadcast domain is defined as a set of devices that can communicate with each other at the Data Link layer. Therefore, in a network that does not include higher layer devices, all of the network devices are in the same broadcast domain. In broadcast frames, the hexadecimal destination MAC address is always ff:ff:ff:ff:ff:ff which, in binary notation, is a series of 48 bits, each set to a value of 1. All devices in the broadcast domain recognize and accept frames with this destination MAC address. Instructor Note Be sure that students understand hexadecimal vs. binary notation, but do not take this topic beyond the scope of this course. Since broadcasting reaches all devices within a broadcast domain, Ethernet can use this capability to perform various device setup and control functions. This is a very useful feature, allowing implementation and growth of a LAN with little intervention from a network administrator. Figure 1-9 shows a broadcast transmission in which Station A is transmitting frames with this broadcast destination MAC address. All devices in the same broadcast domain as Station A receive and process the broadcast frames. Figure 1-9: Broadcast Frame Now that we have covered some basic concepts for LANs and Ethernet transmission, lets continue by discussing how devices on Ethernet LANs are connected. Instructor Note Check the existing knowledge of students on the differences among switches, hubs, routers, and gateways. Initiate a discussion around the differences among these devices and their suitability to different applications. Repeaters and Hubs A very simple LAN topology consists of network devices that are all connected directly to a shared medium as shown in Figure 1-10. If we need to connect more devices to the LAN, we are limited by the characteristics of the shared media. Devices such as repeaters and hubs can be used to overcome distance limitations of the media, allowing the reach of the network to be extended. Figure 1-10: Simple LAN Topology Repeaters are Physical layer devices that regenerate a signal, which effectively allows the network segment to extend a greater distance. As shown in Figure 1-11, we can use the additional segment length to add more devices to the LAN. Keep in mind that devices added through implementation of repeaters are still in the same collision domain as the original devices. This results in more contention for access to the shared transmission media. Such devices are in little use today. Figure 1-11: LAN Extended with a Repeater As shown in Figure 1-12, hubs can also be used to extend the distance of a LAN segment. Hubs are Layer 1 (physical) devices. The advantage of a hub versus a repeater is that hubs provide more ports. Increased contention for media access still exists since the additional devices connected to the hub(s) are still in the same collision domain. Figure 1-12: LAN Extended with a Hub Ethernet Bridges and Switches Ethernet bridges and switches are Layer 2 (Data Link) devices that provide another option for extending the distance and broadcast domain of a network. Unlike repeaters and hubs, bridges and switches keep the collision domains of connected LAN segments isolated from each other as shown in Figure 1-13. Therefore, the devices in one segment do not contend with devices in another segment for media access. Figure 1-13: LAN Extended with an Ethernet Switch Frame Forwarding with Ethernet Switches As Layer 2 devices, Ethernet switches make frame-forwarding decisions based on source and destination MAC addresses. One of the processes used in making these decisions is MAC learning. To make efficient use of the data pathways that are dynamically cross connected within an Ethernet switch, the switch keeps track of the location of as many active devices as its design allows. When an Ethernet frame ingresses (enters) a switch, the switch inspects the frames source address to learn the location of the sender and inspects the destination address to learn the location of the recipient. This knowledge is kept in a MAC address table. Figure 1-14 shows an example of a MAC address table. As long as the sender remains connected to the same physical port that their MAC address was learned on, the switch will know which port to forward frames to that are destined for that particular senders address. Figure 1-14: MAC Address Table MAC address information stored in a MAC address table is not retained indefinitely. Each entry is time stamped; and if no activity is sensed for a period of time, referred to as an aging period, the inactive entry is removed. This is done so that only active devices occupy space in the table. This keeps the MAC address table from overloading and facilitates address lookup. The default aging period is typically five minutes. Figure 1-15 shows how an Ethernet switch forwards frames based on entries in the MAC address table. The forwarding process consists of the following steps: Inspect the incoming frames MAC destination address: If the MAC destination address is a broadcast address, flood it out all ports within the broadcast domain. If the MAC destination address is a unicast address, look for it in the MAC address table. If the address is found, forward the frame on the egress (exit) port where the NE knows the device can be reached. If not, flood it. Flooding allows communication even when MAC destination addresses are unknown. Along with multicast, which is actually a large set of special-purpose MAC addresses, network traffic can be directed to any number of devices on a network. Inspect the incoming frames MAC source address: If the MAC source address is already in the MAC address table, update the aging timer. This is an active device on the port through which it is connected. If the MAC source address is not currently in the MAC address table, add it in the list and set the aging timer. This is also an active device. Periodically check for MAC address table entries that have expired. These are no longer active devices on the port on which they were learned, and these table entries are removed. If a device is moved from one port to another, the device becomes active on the new ports MAC table. This is referred to as MAC motion. An Ethernet switch will purposely filter (drop) certain frames. Whether a frame is dropped or forwarded can depend on the switch configuration, but normal switch behavior drops any frame containing a destination address that the switch knows can be reached through the same port where the frame was received. This is done to prevent a device from receiving duplicate frames. Figure 1-15: Frame-Forwarding Process A MAC Learning and Broadcast Domain Analogy Mail Delivery Consider this following analogy to understand the concept of MAC learning and broadcast domain: Consider a situation where your friend wants to send you a birthday party invitation (the invitation represents an Ethernet frame). You and your friend live on the same street (the street represents a broadcast domain). However, there is a problem. Your friend does not know your house address so she writes her return (source) address on the birthday party invitation card and writes the street name as your (destination) address. Your friend drops the envelope in her mail box (your friends mail box represents a LAN) as shown in Figure 1-16. Figure 1-16: Broadcast Analogy, Part 1 When the mail carrier picks up the mail, he notices that the destination address is unknown. The postman goes to a copier and makes enough copies so that he can deliver one copy to each possible destination address on the street. This would mean every house on the street, except for your friends house, will get a copy of the invitation. After the postman has delivered the envelopes to all the houses (this process is analogous to a broadcast transmission), you receive the birthday party invitation and recognize your name on the envelope. So, you open the envelope and read the invitation. Figure 1-17: Broadcast Analogy, Part 2 All of your neighbors receive copies of the same envelope, but they see that the name is not theirs so they simply discard it. After reading the invitation, you send a thank you card back to your friend with your friends address; and you include a return (source) address. The postman sees that this envelope has a specific destination address so it can be delivered without broadcasting. It also has a source address, so the postman now knows your address. It is now possible to exchange mail directly with your friend without broadcasting letters to your neighbors. In other words, you can communicate using unicast transmission. If you and your friend were on different streets (broadcast domains), you would have never received your invitation card; and communication could have never occurred. Multilayer Switches and Routers In this course, our discussion of switching focuses on switching at the Data Link level since Ethernet is a Layer 2 technology. However, switching can also be

History of Soul Music

History of Soul Music Christina Ivery University of Phoenix RES/110 John Thomas February 11, 2010 Soul music was a voice for blacks during a time of war and segregation, aside of leaders like Dr. Martin Luther King, Jr. and Malcolm X.. As stated by a historian Peter Guralnick, â€Å"It was as if the rhythm and blues singer, like the jazz musician and professional athlete before him, were being sent out as an advance scout into hostile territory†. (Santoro,2003). John Ponomarenko says Soul music originated from African Spirituals, â€Å"the first references to spiritual songs sung by black slaves dated as far back as 1828-1850†. Black spirituals were often used as work songs and sometimes contained coded information s form of secret communication, songs such as â€Å"Deep River, Roll Jordan Roll, and Wade in the Water to name a few. Soul Music began in the late 1950’s and the early 1960’s. Many studios developed in inner cities such as Detroit, Chicago, and Memphis and each had a sound of its own. This also encouraged competition and talent from all over the world. Soul music came at a time of the civil rights movement and gave all blacks a voice for their many battles within their neighborhoods and overseas as well. The staggering war on segregation was a major driving force for soul music during that time. The events in the Deep South inspired many musicians, for example; seeing black protestors hosed down in the streets with fire hydrants and beaten repeatedly with clubs as if their voices were lethal weapons. Soul music was originated in the United States primarily by African American musicians starting with the blending of gospel, rhythm, and blues. Gospel sounds and Christianity were far from the sounds of Ray Charles and James Brown singing of love, women, and good times. Piero Scaruffi stated, â€Å"James Brown, known as the King of soul, began a movement all on his own, captivating people with is powerful voice and his electrifying dance moves. â€Å"Say it aloud I’m Black and proud† was blazing from the radio sound in 1968, and said it all in the title. It became the new black national anthem. One of the first to enhance the use of a live band and gave his first choreographed show on Live at the Apollo†. Developed from a merge of gospel, blues, and jazz it came with emotions that could move anyone. Gene Santoro stated, â€Å"soul music was known as â€Å"white crossover music†, it was suddenly a way for blacks to be seen on television and most teen oriented music programs with close to no white stars†. This music was something of their own that was uplifting during a depressing time in history that everyone could dance with. Whites and blacks alike related for once because of the sounds of great soul music. The pioneers of soul music were known for their distinctive voices, voices that could only come from people who felt or was feeling traumatizing emotional pain. Their voices truly matched their ongoing struggle. Soul Music was the epitome of music in the 1960’s; many artists emerged as true musical superstars. Artists like Aretha Franklin from Detroit, who made her first recording as a gospel artist when she was the age of 14 with Columbia records signed by John Hammond. Stated by Richie Unterberger, â€Å"she made history with hit songs such as I never loved a man (the way that I love you), Respect, Chain of Fools, and I Say a Little Prayer. Soul music got people off their seats and clapping their hands, something that people could feel all through your body. Marvin Gaye was another soul singer that paved the way for musicians young and old, while also redefining soul. As stated by (Ankeny, 2008) â€Å"with one of the greatest songs to hit the charts that altered the face of black music â€Å"What’s going On† forged a sophisticated sound and incorporated jazz with classical elements†. What’s Going On also brought the sound of the spiritual believe back to the forefront of soul music. Once again soul was singing of the issues ranging from poverty and discrimination of the environment, drug abuse and political corruption, mainly the conflict in the Vietnam War. Other great hits included Ain’t No Mountain High Enough, You Precious Love and Your all I Need to Get By. Marvin sang of the issues of the times like no one else. I recall the day that Marvin Gaye was pronounced dead. My mother cried terribly as I imagine quite a large part of the world did that day. It was if soul was gone from that moment forth. It was sad moments in history that I myself will hold as a paused moment in time. However, this music brings me strength from the many songs that my ancestors before me sang for freedom or of agony; or the stories that are told through rhythm and blues that tell the history of blacks of sorrow and pain. Many songs can make people cry but it takes a mighty strong people to take that sorrow and turn it into something of their own. These artists left huge footsteps for new artist’s to follow in this time of confusion and free agency and free choice. Throughout all the chaos, soul has the few that are paving the way and would make our past icons proud of the music that these artist’s produce. Artists such as Erika Badu, Leela James, and Mary J. Blige are just a few of the icons today that keep the soul alive. For this reason soul music will not die for years to come. Soul music began with words that tell of history and how to achieve freedom. It tells Americas who we are, were we came from and where we want to go. So sing with me. References Ponomarenko, J. (2005, August) retrieved from ttp://www. localdial. com/users/jsyedu133/Soulreview/Understandingpages/the5. htm Peiro Scaruffi. (2005). A brief history of soul music. Retrieved from http://www. scaruffi. com/history/soul. html Santoro, G. (2003). Sweet Soul Music. Retrieved from  University of Phoenix eBook Collection database. Ponomarenko, J. (2005). The history of Soul. Retrieved from www. localdial. com/users/jsyedu133/soulreview/understandingpages/the5. htm Unterb erger, R. (2010). The Queen of Soul, Aretha Franklin. Retrieved from www. aretha-franklin. com/bio. htm

Similarities Between The Glass Menagerie And A Dolls House

Realism is â€Å"An attempt to reproduce faithfully the surface appearance of life, especially that of ordinary people in everyday situations† (Kennedy 2081). Realism is shown throughout the two following plays. The Glass Menagerie is a play written by Tennessee Williams, and it was published in the year of 1945. The play being compared is A Doll’s House, written by Henrik Ibsen it was published in the year of 1879. In A Glass Menagerie realism is shown through the fact that Tom’s family is struggling with money. Tom can be seen as the protagonist of the story. Similarly, in A Doll’s House Nora’s family was struggling with money up until this year. Nora can be seen as the protagonist in this story. In A Doll’s House the claims given about†¦show more content†¦Nora and her husband have just found money through her husband’s raise at the bank, but Noar is unhappy with her relationship with Herman. â€Å"I mean that I was just passed from Papa’s hands to yours. You arranged everything according to your own taste, and so I had all the same taste’s† (Isben 1606). Nora is not happy with where she is in the relationship. She is just being led like cattle, but she is now leaving so she will not have to deal with it anymore. â€Å"I’m leaving right now† (Ibsen 1606). There are similarities and differences in these aspects between the two plays. Tom in The Glass Menagerie is also sympathized for, but he is not the center of attention until the end of the play. Laura and Jim are the center of attention. This is until the audience finds out Jim and his girlfriend Betty are â€Å"going to be married the second of June† (Williams 1656). The tone in this play can be seen as gloomy. Not one character in this play has found what they want in life. Tom wants happiness, his mother wants a good man, and Laura wants a husband to love her. Tom in The Glass Menagerie wants to better h is career and life, and Nora in A Doll’s house wants to better herself and pay back the debt she owes to Krogstad. In the end they both achieve their goal.In The Glass Menagerie Tom leaves to find a better life for himself, but he is then left with thinking about his sister and how he did her wrong. â€Å"Oh, Laura, Laura, I tried to leave youShow MoreRelatedEssay Prompts4057 Words   |  17 Pageson the Floss The Awakening Moby-Dick Billy Budd Mrs. Dalloway Bleak House Native Son Bless Me,Ultima One Hundred Years of Solitude Catch-22 Othello Crime and Punishment The Scarlet Letter The Crucible Slaughterhouse-Five A Farewell to Arms Song of Solomon Ghosts The Stone Angel The Great Gatsby The Stranger Heart of Darkness A Tale of Two Cities The House of Mirth Their Eyes Were Watching God Jude the Obscure 2003 (Form A): According