Network Planning and Design

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Introduction
Computer network technologies have been growing explosively and the study in computer networks is being a challenging task. Network is a complex mix of applications, communications protocols and page link technologies, traffic flows and routing algorithms. It is immensely complex. Network design process is a challenging task, requiring designers to balance user performance expectations with costs and capacities.
Fundamentals of Networking
A network is simply a group of two or more Personal Computers linked together. Many types of networks exist, but the most common types of networks are Local-Area Networks (LANs), and Wide-Area Networks (WANs). In a LAN, computers are connected together within a "local" area (for example, an office or home). In a WAN, computers are further apart and are connected via telephone/communication lines, radio waves or other means of connection.

Categories of a network
Networks are usually classified using three properties: Topology, Protocol and Architecture. Topology specifies the geometric arrangement of the network. Common topologies are a bus, ring and star. You can check out a figure showing the three common types of network topologies here. Protocol specifies a common set of rules and signals the computers on the network use to communicate. Most networks use Ethernet, but some networks may use IBM's Token Ring protocol. We recommend Ethernet for both home and office networking. For more information, please select the Ethernet page link on the left. Architecture refers to one of the two major types of network architecture: Peer-to-peer or client/server. In a Peer-to-Peer networking configuration, there is no server, and computers simply connect with each other in a workgroup to share files, printers and Internet access. This is most commonly found in home configurations and is only practical for workgroups of a dozen or less computers. In a client/server network there is usually an NT Domain Controller, to which all of the computers log on. This server can provide various services, including centrally routed Internet Access, mail (including e-mail), file sharing and printer access, as well as ensuring security across the network. This is most commonly found in corporate configurations, where network security is essential.

Network Topologies
Network topologies can take a bit of time to understand when you're all new to this kind of cool stuff, but it's very important to fully understand them as they are key elements to understanding and troubleshooting networks and will help you decide what actions to take when you're faced with network problems. There are two types of topologies: Physical and Logical. The physical topology of a network refers to the layout of cables, computers and other peripherals. Try to imagine yourself in a room with a small network, you can see network cables coming out of every computer that is part of the network, then those cables plug into a hub or switch. Logical topology is the method used to pass the information between the computers.



The Bus Topology
Bus topology is fairly old news and you probably won't be seeing much of these around in any modern office or home. With the Bus topology, all workstations are connecting directly to the main backbone that carries the data. Traffic generated by any computer will travel across the backbone and be received by all workstations. This works well in a small network of 2-5 computers, but as the numbers of computers increases so will the network traffic and this can greatly decrease the performance and available bandwidth of your network.


The Hybrid Topology
With the hybrid topology, two or more topologies are combined to form a complete network. For example, a hybrid topology could be the combination of a star and bus topology. These are also the most common in use.