Thursday, April 4, 2019

An Overview of Network Topologies

An Overview of Ne devilrk TopologiesA network topology refers to the way in which nodes in a network be connected to champion another. The network structure defines how they communicate. It is the arrangement with which computer systems or network devices are connected to each other. Topologies may define both physical and logical aspect of the network. Both logical and physical topologies could be homogeneous or different in a same network.Point-to-Point TopologyBus TopologyIn this topology, in all devices share single communication line or cable. This primaeval cable is the backbone of the network and is know as Bus. E precise point communicates with the other point through this Bus. This topology may have worry while multiple hosts sending data at the same time. Therefore, Bus topology either uses CSMA/CD technology or recognizes one host as Bus Master to solve the issue. It is one of the childly forms of networking where a failure of a device does not affect the other dev ices. But failure of the shared out communication line can make all other devices stop functioning.Both ends of the shared crease have line terminator. The data is sent in only one direction and as briefly as it reaches the extreme end, the terminator removes the data from the line.A signal from the source is broadcasted and it travels to all workstations connected to cumulation cable. Although the message is broadcasted but only the intended recipient, whose mac address or IP address matches, accepts it. If the MAC /IP address of machine doesnt match with the intended address, machine discards the signal.A terminator is added at ends of the central cable, to prevent bouncing of signals. A barrel connector can be used to extend it. on a lower floor I have given a basic diagram of a bus topology and consequently have discussed advantages and disadvantages of Bus Network TopologyAdvantagesDisadvantagesIt is easy to set-up and extend bus network.If the main cable (Bus) encounters rough problem, whole network breaks down.Cable length required for this topology is the least compared to other networks.Proper result is required to dump signals. Use of terminators is must.Bus topology costs very less.It is not suitable for networks with strained traffic.Linear Bus network is mostly used in small networks. Good for LAN.Security is very low because all the computers receive the sent signal from the source.Table 1Star Topology clique Topology Mesh TopologyTree TopologyHybrid TopologyIP AddressingAn net communications protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions host or network interface identification and location addressing. Two versions of IP technology exist today. Traditional category computer networks use IP version 4 (IPv4), but some other networks, particularly those at educational and research institutions, have adopted the next generation IP version 6 (IPv6).Internet Protocol Version 4 (IPv4)IPv4 is the fourth version in the development of the Internet Protocol (IP) and the scratch line version of the protocol to be widely deployed. IPv4 is described in IETF publication RFC 791 (September 1981), replacing an earlier interpretation (RFC 760, January 1980).IPv4 ClassesClassIP Start RangePurposeA0 127B128 191C192 223D224 239MulticastE240 255ResearchTable 2Class AClass BClass CInternet Protocol Version 6 (IPv6)IPv4 vs IPv6 ComparisonFeatureIPv4IPv6Deployed19811999Size32 bits (4 Bytes)128 bits (16 Bytes)Unit parcelling8 bits X 416 bits X 8No of IPs232 =2128 = 3.4 X 1038UnicastingYesYesMulticastingYesYesBroadcastingYesNoAny castingNoYesAddress FormatDotted Decimal annotation(192.168.1.1)Hexadecimal Notation(3FFEF2000234AB00)Table 3 IPv4 vs IPv6Network ModelsNetwork models define a set of network layers and how they interact. There are sev eral different network models depending on what organization or company started them. The most important two areISO OSI ModelThe International Standards Organization (ISO) has defined a standard called the Open Systems Interconnection (OSI) book of facts model. This is a seven-layer architecture listed in the next section.TCP/IP ModelThis model is sometimes called the defense lawyers model since it was designed for the department of defense It is also called the internet model because TCP/IP is the protocol used on the internet.ISO OSI ModelLayer NoLayer NamePDUDescription7 performance6Presentation5Session4Transport3Network2Data-link1PhysicalVLANSEthernetNetwork StandardsNoTasksWeek 1Week 2Week3Week4123456Table 5 Gantt ChartTutorialsPoint, 2017, DCN Computer Network Topologies. Online. Available at Accessed on 18th February 2017

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