International Journal of Engineering Trends and Technology (IJETT) – Volume22 Number 7- April 2015 ―A Brief View of Computer Network Topology for Data Communication and Networking‖ Asra Anjum1, Shaik Apsar Pasha2 1Asst.Prof., The Vazir Sultan College of Engineering, Khammam – 507 001, Telangana.(India). 2Asst.Prof., The Vazir Sultan College of Engineering, Khammam – 507 001, Telangana.(India) Abstract- The goal of this paper is to provide a brief view Physical topologies [8-9] and Logical topologies [8- on Computer Network Topologies for Data 9]. Physical Network Topology emphasizes the Communication that may be useful to Computer Network hardware associated with the system including Engineers in understanding to engineer the complex, workstations, remote terminals, servers, and the large and interdisciplinary systems of systems and aiming associated wiring between assets. Conversely, to support the in designing of interconnection systems for data communications. The classification of Network Logical Network Topology emphasizes the topologies by how they are implemented is considered in representation of data flow between nodes. In this detail through several aspects. Each kind of topology is paper a brief description on these topologies are used to achieve a particular task and capture the structure presented. of the system at various levels of detail. In recent days for II. DATA COMMUNICATION computing, distributed computer systems are playing a vital role and popular issue. It delivers high end Data communications have become so much performance at a low cost. Autonomous computers are a part of our lives that we often take them for connected by means of a communication network in a distributed computing environment which is arranged in granted, yet they provide an infrastructure for the a geometrical shape called network topology. In the way that we do so much in the 21st century. For present paper a detailed study and analysis on network businesses, data communications place a vital role to topologies is presented. Definitions of Physical and success in the marketplace, particularly with the Logical Topologies are also provided increasing trend toward globalization. Communications networks allow both individuals Keywords-Data Communication (DC), Bus, Star. and teams to communicate faster and better, obviate the need for many in-person meetings, and even I. INTRODUCTION transfer funds electronically. Through local, Distributed computing systems have become metropolitan, or wide area networks, individual the essential aspect of growing information computers or workstations can be linked together to technology and in computer networking. The enable data sharing and communication. Networks performance of any distributed system is depends on can also be linked with each other to better meet the by the technology, which we adopt in making needs of the organization and the growing demands network interconnections and how data for communication and data in the Information Age. communication takes place. Information transmission is no longer Network topologies [1-2, 8-9] are the limited to what we can place on paper. Large technology for arrangement of various computer computer systems can hold and manipulate quantities elements like links, nodes etc. Basically network of data in ways that just a few decades ago would topology is the topological structure [5] of a have seemed impossible. Not only can these be computer network. In mathematics topology is linked together in a myriad of ways, but can also be concerned with the connectedness of objects which is transmitted nearly instantaneously over the most basic properties of space. In simple way communications networks — sets of locations (or network topology refers to the way in which the nodes) with concomitant hardware, software, and network of computers [5, 6-7] is connected. Each information that are linked together to form a system topology is suited to specific tasks and has its own that transmits and receives information. advantages and disadvantages. A most simple and good example of network topology is LAN [3-4, 8- Data Communication refers to the 9]. Where it LAN has one or more physical links to transmission/exchange of digital data between a other devices in the network. In recent days there are source and a receiver. The physical connection basically two basic categories of network topologies: between networked computing devices is ISSN: 2231-5381 http://www.ijettjournal.org Page 319 International Journal of Engineering Trends and Technology (IJETT) – Volume22 Number 7- April 2015 established using either guided (wired) media or network of computers [5, 6-7] is connected. Till wireless media. The best-known computer network today various types of topologies are existed. Each is the Internet. Data communication is said to be topology is suited to specific tasks and has its own local if communicating devices are in the same pros and cons. The choice of topology is dependent building or a similarly restricted geographical area. upon type and number of equipment being used, planned applications and rate of data transfer A simple data communication system has required, response time, and cost. Topology can also shown in Fig-1. be defined as the geometrically interconnection pattern by which the stations (nodes/computers) are connected using suitable transmission media (which can be point-to-point and broadcast). A most simple and good example of network topology is LAN [3-4, 8-9]. Where it LAN has one or There are three types of data more physical links to other devices in the network. communications networks exist. They are Local area In recent days there are basically two basic categories networks, Metropolitan area and Wide area networks. of network topologies, they are Physical topologies Local area network comprise multiple desktop [8-9] and Logical topologies [8-9]. Physical Network computers that are located near each other and linked Topology emphasizes the hardware associated with into a network that allows the users to share files and peripheral devices such as printers, fax machines, or the system including workstations, remote terminals, storage devices. A second type of network used in servers, and the associated wiring between assets. many businesses is the metropolitan area network. Conversely, Logical Network Topology emphasizes This type of network transmits data and information the representation of data flow between nodes. A citywide (up to 30/40 miles) and at greater speeds brief view of various commonly used topologies are than a local area network. As opposed to local area presented and discussed in this paper. networks, metropolitan area networks are optimized for both voice and data transmissions and can, A. Point-to-Point therefore, carry more forms of data than can be In a point-to-point link, two devices carried over local area networks. These include monopolize a communication medium. Because the combinations of voice, data, image, and video data. medium is not shared, a mechanism is not needed to Metropolitan area networks typically operate over a identify the computers. Therefore, a simple, two- city-wide network of fiber optic cables. The third device point-to-point network has no need for type of network is the wide area network. These addressing. A point to point topology is a direct networks comprise multiple computers that are connection between two devices (nodes), the value of widely dispersed and that are linked into a network. a permanent point-to-point network is unimpeded Wide area networks typically use high speed, long communications between the two endpoints. One distance communications networks or satellites to example of this is a PC connected to a printer. A connect the computers within the network. more common example is a mainframe terminal connected to a mainframe front-end processor. III. TOPOLOGY Point-to-point links can be simplex, half- Topology refers to the way in which the network duplex, or full-duplex. When devices must engage in of computers is connected i.e. how the network is laid bi-directional communication on a half-duplex link, out. Network topologies [1-2, 8-9] are the some turnaround mechanisms must be in place to technology for arrangement of various computer switch the roles of the sending and receiving devices. elements like links, nodes etc. Basically network In Simplex signal flows in ONE direction and only topology is the topological structure [5] of a one station transmit and the other receive, In Half- duplex each station can both transmit and receive but computer network. In mathematics topology is NOT at the same time and where as in Full-duplex concerned with the connectedness of objects which is both stations transmit and receive simultaneously, the most basic properties of space. In simple way Link capacity is shared between the two devices network topology refers to the way in which the either by 2separate transmission path and channel capacity is divided for transmitting and receiving. ISSN: 2231-5381 http://www.ijettjournal.org Page 320 International Journal of Engineering Trends and Technology (IJETT) – Volume22 Number 7- April 2015 By this type topology, if one node goes faulty all nodes may be affected as all nodes share the same cable for the sending and receiving of information. So the main weakness i.e. Drawbacks of bus topologies are Due to Heavy network traffic can slow a bus considerably because any computer can Figure II. Point-to-point. transmit at any time. But networks do not coordinate when information is sent. Computer interrupting each B. Multi-Point other can use a lot of bandwidth. Bus topology have In a Multi-Point link, three or more devices the problem of each connection between two cables together through a single communication medium. weakens the electrical signal and the bus For sharing a common channel, each device needs a configuration can be difficult to find and can cause way to identify itself and the device to which it wants the whole networks to stop functioning.