Internetworking Basics Doc. Wiki. From Doc. Wiki. This article along with the next six articles acts as a foundation for the technology discussions that follow. In this article, some fundamental concepts and terms used in the evolving language of internetworking are addressed. List Of Hotmail Email Addresses Download Adobe. In the same way that this book provides a foundation for understanding modern networking, this article summarizes some common themes presented throughout the remainder of this book. Topics include flow control, error checking, and multiplexing, but this article focuses mainly on mapping the Open System Interconnection OSI model to networkinginternetworking functions, and also summarizing the general nature of addressing schemes within the context of the OSI model. Transmit 4 Serial Number Mac' title='Transmit 4 Serial Number Mac' />The OSI model represents the building blocks for internetworks. Understanding the conceptual model helps you understand the complex pieces that make up an internetwork. What Is an Internetwork An internetwork is a collection of individual networks, connected by intermediate networking devices, that functions as a single large network. Internetworking refers to the industry, products, and procedures that meet the challenge of creating and administering internetworks. Figure Different Network Technologies Can Be Connected to Create an Internetwork illustrates some different kinds of network technologies that can be interconnected by routers and other networking devices to create an internetwork. Transmit 4 Serial Number Mac' title='Transmit 4 Serial Number Mac' />Figure Different Network Technologies Can Be Connected to Create an Internetwork History of Internetworking The first networks were time sharing networks that used mainframes and attached terminals. Such environments were implemented by both IBMs Systems Network Architecture SNA and Digitals network architecture. Local area networks LANs evolved around the PC revolution. LANs enabled multiple users in a relatively small geographical area to exchange files and messages, as well as access shared resources such as file servers and printers. Wide area networks WANs interconnect LANs with geographically dispersed users to create connectivity. Some of the technologies used for connecting LANs include T1, T3, ATM, ISDN, ADSL, Frame Relay, radio links, and others. New methods of connecting dispersed LANs are appearing every day. Today, high speed LANs and switched internetworks are becoming widely used, largely because they operate at very high speeds and support such high bandwidth applications as multimedia and videoconferencing. Internetworking evolved as a solution to three key problems isolated LANs, duplication of resources, and a lack of network management. Isolated LANs made electronic communication between different offices or departments impossible. Duplication of resources meant that the same hardware and software had to be supplied to each office or department, as did separate support staff. This lack of network management meant that no centralized method of managing and troubleshooting networks existed. Internetworking Challenges Implementing a functional internetwork is no simple task. Many challenges must be faced, especially in the areas of connectivity, reliability, network management, and flexibility. Each area is key in establishing an efficient and effective internetwork. The challenge when connecting various systems is to support communication among disparate technologies. Different sites, for example, may use different types of media operating at varying speeds, or may even include different types of systems that need to communicate. Transmit 4 Serial Number Mac' title='Transmit 4 Serial Number Mac' />Because companies rely heavily on data communication, internetworks must provide a certain level of reliability. This is an unpredictable world, so many large internetworks include redundancy to allow for communication even when problems occur. Furthermore, network management must provide centralized support and troubleshooting capabilities in an internetwork. Configuration, security, performance, and other issues must be adequately addressed for the internetwork to function smoothly. Security within an internetwork is essential. Many people think of network security from the perspective of protecting the private network from outside attacks. However, it is just as important to protect the network from internal attacks, especially because most security breaches come from inside. Networks must also be secured so that the internal network cannot be used as a tool to attack other external sites. Early in the year 2. DDOS attacks. These attacks were possible because a great number of private networks currently connected with the Internet were not properly secured. These private networks were used as tools for the attackers. Because nothing in this world is stagnant, internetworks must be flexible enough to change with new demands. Open Systems Interconnection Reference Model The Open Systems Interconnection OSI reference model describes how information from a software application in one computer moves through a network medium to a software application in another computer. The OSI reference model is a conceptual model composed of seven layers, each specifying particular network functions. The model was developed by the International Organization for Standardization ISO in 1. The OSI model divides the tasks involved with moving information between networked computers into seven smaller, more manageable task groups. A task or group of tasks is then assigned to each of the seven OSI layers. Each layer is reasonably self contained so that the tasks assigned to each layer can be implemented independently. This enables the solutions offered by one layer to be updated without adversely affecting the other layers. The following list details the seven layers of the Open Systems Interconnection OSI reference model. Layer 7 Application. The Settlers 7 Offline Crack Machine'>The Settlers 7 Offline Crack Machine. Layer 6 Presentation. Layer 5 Session. Layer 4 Transport. Layer 3 Network. Layer 2 Data link. Layer 1 Physical. All Application layer. People Presentation layer. Seem Session layer. To Transport layer. Need Network layer. Data Data link layer. Processing Physical layer. Figure The OSI Reference Model Contains Seven Independent Layers illustrates the seven layer OSI reference model. Figure The OSI Reference Model Contains Seven Independent Layers Characteristics of the OSI Layers The seven layers of the OSI reference model can be divided into two categories upper layers and lower layers. The upper layers of the OSI model deal with application issues and generally are implemented only in software. The highest layer, the application layer, is closest to the end user. PowerMacG4. com how to upgrade your Apple Power Mac G4. Overclock your G4. Links to purchase PowerMac G4 systems. Install a Pioneer SuperDrive. G4 PowerMac Resources. The Blutronium Serial Bluetooth Adapter is a user friendly adapter with several advanced features. Use it to communicate with any serial RS232 device. Both users and application layer processes interact with software applications that contain a communications component. The term upper layer is sometimes used to refer to any layer above another layer in the OSI model. The lower layers of the OSI model handle data transport issues. The physical layer and the data link layer are implemented in hardware and software. The lowest layer, the physical layer, is closest to the physical network medium the network cabling, for example and is responsible for actually placing information on the medium. Figure Two Sets of Layers Make Up the OSI Layers illustrates the division between the upper and lower OSI layers. Figure Two Sets of Layers Make Up the OSI Layers Protocols The OSI model provides a conceptual framework for communication between computers, but the model itself is not a method of communication. Actual communication is made possible by using communication protocols. Getting Started On Electric Guitar With Keith Wyatt Games there.