Star topology
Star topology is a popular network configuration in which each device, such as a computer or printer, connects individually to a central hub or switch. This design resembles a star, with cables radiating from the hub, allowing for efficient communication and management of network traffic. Star topology is widely used in homes, offices, and schools due to its reliability and the ease with which devices can be added or removed without disrupting the entire network. One major advantage is that it simplifies troubleshooting, as each device operates independently, making it easier to identify and fix issues. However, the system does have drawbacks, including the need for more cabling and the reliance on a central hub—should this hub fail, the entire network becomes inoperative.
Organizations may also implement variations of star topology, such as compound star networks, which connect multiple star systems, or dual-star systems that enhance reliability by connecting devices to two hubs. Hybrid systems that combine star topology with other configurations can be tailored to specific needs, such as improved security or redundancy. Overall, star topology is a fundamental concept in networking that balances simplicity with security, making it a favored choice for many different settings.
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Star topology
Star topology is one of the most commonly used computer network formations for offices, schools, and homes. Each component of the system, such as a computer or a printer, individually connects to a central hub. This central point may be a computer hub, a concentrator, or a switch, and multiple computers or other components may be controlled by it. The system is called a star topology because the cables connecting each component radiate from the central hub like the points of a star. The star system is very popular for home and commercial installations because it offers high reliability and allows for good security control. A star system can be costly to install, however, and a failure of the main hub prevents any of the computers or other components in the system from working.
Background
The common name for a group of several computers that are connected to one another is a local area network, or LAN. A network is a system of devices connected in a way that enables communication between them and, potentially, beyond the system. Systems with multiple computers and devices are set up in network configurations called topologies. The word topology is derived from the Greek word topos, which means "place." The word refers to how the parts of a system are arranged.
Computer systems are generally set up in one of five configurations or topologies. These include bus, ring, tree, mesh, and star. In bus topology, components connect to a single cable called a backbone. Bus topology works best with smaller systems. Ring topology is used mostly in offices or schools. Ring topology connects each computer to two others. In mesh topology, computers and other components are connected to one another via multiple routes. Tree topology is sometimes called expanded star topology because it joins multiple star systems together on a bus; this compensates for the shortfalls of both systems. For example, a star topology may include more computers than a bus topology, but bus topologies are limited by the number of connection points on the hub. Connecting a series of star systems along a cable like the one used in a bus system allows for the connection of more devices.
Overview
In systems that use star topology, every device connected to the system sends information to the hub, or central device, before it goes anywhere else. This allows the central device to serve as a control point for every device on the system. Star topology is very common for home computer installations that connect more than one computer. The ability to add multiple components and the fact that multiple star systems can be connected, however, make star topology very useful in systems that need to connect many computers. The most common kind of cable used to connect computers and peripherals such as printers is an unshielded twisted pair (UTP) Ethernet cable.
Star topology systems offer many advantages over other types of topologies. Star topology is a relatively simple system that does not require complicated connections. Finding problems on a system that uses start topology is easier because each computer and peripheral remains separate. The system limits the amount of computer nodes—or individual devices on the network—through which data pass. This protects data integrity and increases the speed with which data travel. This limited contact protects the devices and makes security easier, since all data go into and out of the central hub. The separateness of the components makes it possible to repair or replace individual computers, printers, scanners, and so on without disabling the entire system.
The star system does have some disadvantages, however. It requires additional cables to run a separate line for each device. The system requires a central hub or switch. These two factors add to the cost of setting up the system. The fact that everything is connected to one device means that if that device fails, the entire system will fail. The size of the system is limited by the capacity of the central hub. The size issue can be overcome by converting the star system to a tree system and connecting it to another system, but this adds to the cost of installing and maintaining the system.
As computer use and technology continue to expand, new ways of connecting computer networks have been devised. These are usually derivations or variations of the five main types mentioned previously. One of these variations is known as a compound star network. This type of network connects several star networks directly from one hub to another. This differs slightly from tree topology. A tree configuration has all the stars connecting to one central "trunk" hub, whereas the hubs in a compound star network can be connected to one another in a chain-like formation.
In some cases, star networks are set up with two hubs. In this case, each computer or peripheral is connected to each of the hubs. The hubs are also connected. This type of system, called a dual-star system, provides some redundancy that protects against system failure. In some cases, two of these systems are paired to form a dual-dual star system. Two dual-star systems are connected by having the peripherals connect to all four hubs; however, the two paired sets of hubs are not connected to each other. Star systems can be combined with other systems to meet special needs for security, redundancy, and so on. These are called hybrid systems.
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