Network Topologies
What is a Topology?
A Local Area Networks’ physical layout of its resources is called a topology. The connection of a topology always involves two or more computers. A network's topology affects its capabilities. The type of topology used will determine the network growth, the capabilities of the equipment, the type of equipment needed and the network management.
Physical Topology
A physical topology is the physical layout of devices on a network. Every LAN has a topology, or the way that the devices on a network are arranged and how they communicate with each other. The way that the workstations are connected to the network and the physical structure of the network is called the physical topology.
A network's logical topology is not necessarily the same as its physical topology. For example, twisted pair Ethernet is a logical bus topology in a physical star topology layout.
Logical Topology
The logical topology, in contrast, is the way that the signals act on the network media, or the way that the data passes through the network from one device to the next without regard to the physical interconnection of the devices.
Logical topologies are bound to the network protocols that direct how the data moves across a network. For example, IBM's Token Ring is a logical ring topology, but it is physically set up in a star topology.
Standard Topologies
In the Bus Topology, all devices are connected to a central cable called the backbone. These networks are inexpensive and east to install on small networks. When a sending machine transmits its data, it is transmitted to all devices on that segment. Due to the nature of transmission on a bus network, both ends of the cable or segment must be terminated. Terminators absorb all signals that reach the segment ends. Only one computer at a time can send information on the bus topology. “Because of this limitation, the number of computers attached to a bus network can affect network performance” (p. 51 Tomsho). If a break in the connection occurs, both ends of the network must be sealed with a terminator in order to avoid signal bounce. If cable failure occurs, then the computers can still act as standalones, but “no network communications are possible” (p. 51 Tomsho). Ethernet systems use the bus topology.
These rules are also known as bus protocols. The design of a bus system contains several pro’s and con’s related to the size of the data bus, data transfer size, bus protocols, and clocking. Bus systems are categorized as asynchronous and synchronous buses depending on whether the bus communications are controlled by a clock. There are parallel and serial buses depending on whether the data bits are sent on parallel wires or multiplexed onto one single wire.
“Network topology is the arrangement of the various network elements such as node, link, of computer network. Basically, it is topological structure of a network which ether be physically or logically.”
... access to what and in which sequence. The router connects the LAN to other networks, which could be the Internet or another corporate network so that the LAN can exchange information with networks external to it. The most common LAN operating systems are Windows, Linux, and Novell. Each of these network operating systems supports TCP/IP as their default networking protocol. Ethernet is the dominant LAN standard at the physical network level, specifying the physical medium to carry signals between computers, access control rules, and a standardized set of bits used to carry data over the system. Originally, Ethernet supported a data transfer rate of 10 megabits per second (Mbps). Newer versions, such as Fast Ethernet and Gigabit Ethernet, support data transfer rates of 100 Mbps and 1 gigabits per second (Gbps), respectively, and are used in network backbones.
Wireless networks – While the term wireless network may technically be used to refer to any type of network that is wireless, the term is most commonly used to refer to a telecommunications network whose interconnection between nodes is implemented without the use of wires, such as a computer network. Wireless telecommunication networks are generally implemented with some type of remote information transmission system that uses electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes place at the physical level or “layer” network.
To attempt to define a network in a few sentences would be a fool’s errand. A network could be seen as simply a grid of interconnecting connections between multiple bodies. However when this vision is applied to real-world systems, they all start to differ. There is not anything that exists in the universe that is not part of a network. A network is the result of different parts or members which have similarities in parts of their identity. This similarity that they have in common, they will also have with other bodies forming a network between them. Most of these factors of identity are different from those of most others. As a result, each factor will be in common with different other members of different networks. Each factor includes this body in a multitude of networks. This means that no one thing is in one and only one network, but is included in many.
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Network topology can be defined in many ways since there are many different types of network that depending on the certain amount of user, ability, and purpose. For example, in Multimedia University (MMU) all networks inside our campus are connected through Local Area Network (LAN) to access MMLS for example. While when connected to outside through internet, we call it Wide Area Network (WAN). We are connected to the world via various network topologies, such as Point-to-point, Bus, Star, Ring, Mesh, Tree, Hybrid, and last but not least Daisy chain. Our interest regarding this Final Year Project is Wireless Mesh Network build based on Mesh Topology.
In conclusion, a local area network is made up of computers and a myriad of devices, such as routers, servers, switches, and firewalls. In order for it to connect to the Internet, a router must be installed. Servers provide special functions such as printing, file sharing, etc. Switches connect the computers together from different parts of the network. Firewalls prevent unauthorized access. There are a host of other devices that may be used as well. These devices are hubs, gateways, repeaters, wireless access points,
It just doesn't get much simpler than the physical bus topology when it comes to connecting nodes on a Local Area Network (LAN). The most common implementation of a linear bus topology is IEEE 802.3 Ethernet. All devices in a bus topology are connected to a single cable called the bus, backbone, or ether. The transmission medium has a physical beginning and an end. All connections must be terminated with a resistor to keep data transmissions from being mistaken as network traffic. The terminating resistor must match the impedance of the cable.
Network diagrams and wiring schematics are essential for reference and troubleshooting. A network diagram shows a logical or physical layout and includes switches, firewalls, routers, WAN links, and IP addresses (TestOut, 2014a). A wiring schematic is a drawing that shows all cables including connections to switches, patch panels, and devices and includes locations and cable numbers.
Local Area Networks also called LANs have been a major player in industrialization of computers. In the past 20 or so years the worlds industry has be invaded with new computer technology. It has made such an impact on the way we do business that it has become essential with an ever-growing need for improvement. LANs give an employer the ability to share information between computers with a simple relatively inexpensive system of network cards and software. It also lets the user or users share hardware such as Printers and scanners. The speed of access between the computers is lighting fast because the data has a short distance to cover. In most cases a LAN only occupies one or a group of buildings located next to each other. For larger area need there are several other types of networks such as the Internet.
Laid out in a line – Has a single cable connecting all of nodes. If one node breaks down the whole network breaks down
This report will describe the two forms of data communications in terms of the physical interfaces and modes of operation. It will describe the features of data communications equipment in relation to synchronous and asynchronous communication including modems, network terminating units and sending and receiving equipment.
The logic used to explain miracles of everyday life, thinking logically helps man to question the functioning of everything around us, the logic used to argue and is somehow a thought an idea that influences us for an action we do in our daily lives.
The term Topology refers to the physical or logical shape or layout of a network. Communication between different nodes within a network is determined by its topology. Mesh, Bus, Ring and Star are four of the most common network topologies, each with advantages and disadvantages in relation to each other.