Monday, August 31, 2009

Types of network diagrams

Types of network diagrams

There are different types network diagrams:

  • Artificial neural network or "neural network" (NN), is a mathematical model or computational model based on biological neural networks. It consists of an interconnected group of artificial neurons and processes information using a connectionist approach to computation.
  • Computer network diagram is a schematic depicting the nodes and connections amongst nodes in a computer network or, more generally, any telecommunications network.
  • In project management a network diagram is the logical representation of activities, that defines the sequence or the work of a project. It shows the path of a project, lists starting and completion dates , and names the responsibilities for each task. At a glance it explains how the work of the project goes together. A network for a simple project might consist one or two pages, and on a larger project several network diagrams may exist. diagrams here are
    • Project network: a general flow chart depicting the sequence in which a project's terminal elements are to be completed by showing terminal elements and their dependencies.
    • PERT network
  • Neural network diagram: ia a network or circuit of biological neurons or artificial neural networks, which are composed of artificial neurons or nodes.
  • A semantic network is a network or circuit of biological neurons. The modern usage of the term often refers to artificial neural networks, which are composed of artificial neurons or nodes]].
  • A sociogram is a graphic representation of social links that a person has. It is a sociometric chart that plots the structure of interpersonal relations in a group situation.

Saturday, August 29, 2009

WAN


A wide area network (WAN) is a computer network that covers a broad area (i.e. any network whose communications links cross metropolitan, regional, or national boundaries [1]). Less formally, a WAN is a network that uses routers and public communications links Contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs), which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well-known example of a WAN is the Internet. A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer.

local area network

LAN:


A LAN is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport. Current wired LANs are most likely to be based on ETHERNET technology, although new standards like ITUC also provide a way to create a wired LAN using existing home wires (coaxial cables, phone lines and power lines)

VIRTUALIZATION

Promise of Virtualization

Virtualization technologies isolate or unbind one computing resource from others and can be applied from the data center to the desktop. Rather than locking the various layers together—the operating system (OS) to the hardware, the application to the OS, and the user interface to the local machine—virtualization loosens the direct reliance these parts have on each other. This results in many opportunities to create efficiencies. For instance, the OS can be decoupled from the physical hardware it runs on using hardware virtualization (including server and desktop virtualization). Similarly, presentation virtualization allows you to separate an application's user interface from the physical machine the application runs on. This makes it possible to run an application in one location but have it be controlled in another.

Solving Real-World Issues

Separating these layers enables much greater flexibility in every aspect of your IT infrastructure. Hardware and software can be used in more diverse ways, and the separation makes them both easier to change. Systems become more secure as a result of isolating problem areas. Tasks traditionally handled by the IT staff become more simplified, and it can eliminate previously unsolvable problems that plague IT every day. From accelerating application deployments; to ensuring systems, applications, and data are always available; to taking the hassle out of rebuilding and taking down servers and desktops for testing and development; to reducing risk, slashing costs, and improving agility of your entire environment, virtualization has the power to transform your infrastructure.

Presentation Virtualization with Terminal Services

Presentation virtualization, one of the core virtualization technologies available in Windows Server 2008, makes it possible to run an application in one location but have it be controlled in another. With Terminal Services presentation virtualization, you can install and manage applications on centralized servers in the datacenter; screen images are delivered to the users, and the user’s client machine, in turn, sends keystrokes and mouse movements back to the server.

When using Terminal Services, administrators can present users with the individual applications and data they require to complete their task, or the whole remote desktop. From a user perspective, these applications are integrated seamlessly—looking, feeling, and behaving like local applications.

WIN 2008 SERVER

The Business Challenge

In today’s complex business environment, there is more pressure than ever on Information Technology (IT) departments to deliver business value, despite challenges such as shrinking budgets, rapidly changing technologies, and increasing security issues. As companies grow, their IT infrastructures typically grow along with them. More often than not however, the pace of that growth is uneven, driven as much by the conditions under which they operate as the model they aspire to. Most organizations increasingly view IT as a key value generator. The focus is shifting from keeping the business up and running to a critical engine that drives responsiveness and agility across the organization.

Organizations are looking to implement technologies which help them to manage their changing workforce and enhance their customer’s experience, as well as continuing to meet the demands and regulations imposed on them. The key challenge is to strike the right balance between managing the infrastructure and adding business value. Analysts say that each year, more than 70 percent of IT budgets are being spent on maintaining what is already in place, as opposed to a mere 30 percent of IT budgets being spent proactively on new initiatives that add business value and increase productivity.

Microsoft Infrastructure Optimization Model


To help companies address the challenge of balancing maintenance with new, more strategic projects, Microsoft has introduced the Infrastructure Optimization (IO) Model. This model outlines the steps companies can take to analyze their current state, and to plan for and create an IT environment that is well managed, more-secure, and efficient. In the most mature state, IT is incorporated into business strategy and is used as a valuable asset in the growth and success of the company.

As part of the IO Model, Microsoft has delivered a set of virtualization technologies allowing IT organizations to significantly reduce operating costs, drive up server utilization, and achieve better return on investment. As a result of moving IT from a cost center to a strategic asset, organizations can free up resources and budget to allow for deeper investment in value-added activities.

INTRO----

Introduction

The network allows computers to communicate with each other and share resources and information. The Advanced Research Projects Agency (ARPA) designed "Advanced Research Projects Agency Network" (ARPANET) for the United States Department of Defense. It was the first computer network in the world in late 1960s and early 1970s