Network Diagram

4 Key excerpts on "Network Diagram"

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  eBook - ePub

  Web Application Design Handbook

  Best Practices for Web-Based Software

  • Susan Fowler, Victor Stanwick(Authors)
  • 2004(Publication Date)
  • Morgan Kaufmann

    (Publisher)

  CHAPTER 12

  Designing Diagrams

  A diagram is a visual method for showing relationships among such things as network elements, employees, and tasks (see Figure 12-1 , for example).

  FIGURE 12-1 Flowchart for an application.1

  This chapter concentrates on designing:

  • diagrams • the software that lets users create diagrams • and the software for showing diagrams

  For information about particular types of diagrams, see Chapter 13 .

  When to Use Diagrams

  Executives and managers use diagrams and charts to communicate difficult concepts. Engineers, technicians, and programmers use them to study problems.

  The importance of diagrams is in how they let users show, talk about, and manipulate relationships. Unlike graphs, the position, size, length, width, fill, or any other characteristic of a line or shape in a diagram has no meaning in itself. The lines and shapes are important only in connection to each other and, ultimately, to the item or idea in the real world with which they are associated.

  Designing Diagram Software

  The word diagram covers a variety of structures: cause-and-effect charts (see Figure 12-2

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  eBook - PDF

  Business Data Communications and Networking

  • Jerry FitzGerald, Alan Dennis, Alexandra Durcikova(Authors)
  • 2020(Publication Date)
  • Wiley

    (Publisher)

  174 Chapter 6 Network Design 6.3.3 Network Design Tools Network modeling and design tools can perform a number of functions to help in the technology design process. With most tools, the first step is to enter a diagram or model of the existing network or proposed network design. Some modeling tools require the user to create the Network Diagram from scratch. That is, the user must enter all of the network components by hand, placing each server, client computer, and circuit on the diagram and defining what each is. Other tools can “discover” the existing network; that is, once installed on the network, they will explore the network to draw a Network Diagram. In this case, the user provides some starting point, and the modeling software explores the network and automatically draws the diagram itself. Once the diagram is complete, the user can then change it to reflect the new network design. Obviously, a tool that can perform network discovery by itself is most helpful when the network being designed is an upgrade to an existing network and when the network is very complex. Once the diagram is complete, the next step is to add information about the expected net- work traffic and see if the network can support the level of traffic that is expected. Simulation, a mathematical technique in which the network comes to life and behaves as it would under real conditions, is used to model the behavior of the communication network. Applications and users generate and respond to messages while the simulator tracks the number of packets in the network and the delays encountered at each point in the network. Simulation models may be tailored to the users’ needs by entering parameter values specific to the network at hand (e.g., this computer will send an average of three 100-byte packets per minute and receive one hundred 1,500-byte packets per minute). Alternatively, the user may prefer to rely primarily on the set of average values provided by the network.

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  eBook - ePub

  Network Analysis, Architecture, and Design

  • James D. McCabe(Author)
  • 2010(Publication Date)
  • Morgan Kaufmann

    (Publisher)

  Logical diagrams show the connectivity and relationships among network devices. Relationships show how devices may interact with one another, how they may work together to provide service and support in the network, and what you might expect from them. For example, you could have a logical diagram showing the routers in your network, or showing just the border routers, or just the interfaces to all external networks. Such diagrams may also include security devices and how they will be connected to the routers, providing insight regarding how the routers and security devices would work together at an external interface.

  Diagrams that focus on logical relationships do so at the expense of accuracy in physical descriptions (i.e., location accuracy). Such diagrams can provide approximate correlations between devices and their physical locations; however, they do not provide an accurate representation of physical space. I refer to such descriptions as logical diagrams and not blueprints, as they do not provide the traditional spatial accuracy and level of detail expected in blueprints. Diagrams showing logical relationships among devices are quite useful as companions to network blueprints, or as early drafts of blueprints. Figure 10.12 is an example of a Network Diagram.

  Figure 10.12 A Logical Diagram of a Communications Closet

  This figure is an example of a communications closet. It shows the types of network devices planned for that closet, and how they are logically connected. For example, from the diagram you can tell that there are multiple firewalls and switches in the communications closet. You can also see the connectivity between devices, to the local networks, and to the Internet. At this stage, however, it does not describe the actual equipment or vendor selections, cable paths or types, or the physical arrangement of the devices in racks or shelves. Diagrams such as these are useful for planning purposes; however, they are not detailed enough to be considered blueprints.

  Another example of a logical diagram is shown in Figure 10.13

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  eBook - PDF

  Network+ Guide to Networks

  • Jill West, Tamara Dean, Jean Andrews, , Jill West, Tamara Dean, Jean Andrews(Authors)
  • 2018(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  Even without a catastrophic event, good documentation makes communication with your coworkers more efficient. It speeds up troubleshooting efforts, and puts information at your fingertips when you face similar problems or challenges in the future. Let’s begin our exploration of network documentation by looking first at the big picture of a network. We’ll then dig into more detailed documentation, and end this chapter with a discussion on how to track changes on a network. Network Diagrams You’ve already learned about the importance of knowledge bases and how to docu- ment problem resolutions in a call tracking system. Recall that a knowledge base is a collection of accumulated insights and solutions to the problems encountered on a net- work. Another critically useful form of documentation is Network Diagrams, which are graphical representations of a network’s devices and connections. These diagrams may show physical layout, logical topology, IP address reserves, names of major network devices, and types of transmission media. In Figure 2-21, you can see an example of a simple Network Diagram showing the physical topology of a small network. Figure 2-22 shows the same network’s logical topology. A Network Diagram is often the product of network mapping, which is the process of discovering and identifying the devices on a network. Several programs are available to assist in detecting, identifying, and monitoring the devices on your network. One of the simpler and most popular tools is Nmap (see Figure 2-23). Nmap was originally designed for Linux as a command-line utility, but has since been expanded for compatibility on sev- eral other OSes. It’s now available in a GUI form called Zenmap (see Figure 2-24). At the end of this chapter, you will install and use Zenmap to discover devices on a network. Network mapping is a fascinating field of study in its own right, and its relevance and importance will only increase as the complexity of today’s networks increases.

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