networking topology | My Assignment Tutor

25/09/20171• Understand networking topology and explorethe size of a required network.• Investigate logical topology (e.g. Ethernet,Token Ring).• Investigate physical topology (e.g. star, ring,bus, mesh, tree, ring).• Explain the impact of network topology,communication and bandwidthrequirements.• Analyse system types looking at real worldscenario and networking types.• Study the system types of peer based, clientserver, cloud, cluster, centralised,virtualised.• Discuss and study different system typesObjectivesOBJECTIVESLO1 Examine networking principles and their protocols25/09/20172In Bus topology, networks use a single backbone cable toconnect all devices in the network.TopologyNetworking 3AdvantagesEasy to connect a computer or peripheral to a linear bus.Requires less cable length than a star topologyDisadvantagesEntire network shuts down if there is a break in the main cableTerminators are required at both ends of the backbone cableDifficult to identify the problem if the entire network shuts downNot meant to be used as a stand-alone solution in a large buildingNetworking 425/09/20173 In Star topology, networks use a Hub or switches todistribute data across the networkTopologyNetworking 5AdvantagesEasy to connect a computer or peripheral to the networkNo disruptions to the network when connecting or removingdevicesEasy to detect faults and to remove partsDisadvantagesRequires more cable length than a bus topology.Entire network shuts down if the (Hubs/Switch) device failsMore expensive topologies because of the cost of the hubs, etc.Networking 625/09/20174In Ring topology, each computer and device areconnected to each other forming a large circle. Eachworkstation is connected to two other components oneither side.TopologyNetworking 7 Advantages Very organised as each node gets to send the data when it receivesan empty token. This helps to reduces chances of collision There is no need for network server to control the connectivitybetween workstations Additional components do not affect the performance of network Each computer has equal access to resources Disadvantages Each packet of data must pass through all the computers betweensource and destination. This makes it slower than Star topology If one workstation or port goes down, the entire network getsaffected Network is highly dependent on the wire which connects differentcomponents MAU’s and network cards are expensive as compared to Ethernetcards and hubsNetworking 825/09/20175Partially and fully meshed topologiesNetworking 9 BodyAreaExamplesITUTelecommunicationsG.992, ADSLH.264, MPEG4IEEECommunications802.3, Ethernet802.11, WiFiIETFInternetRFC 2616, HTTP/1.1RFC 1034/1035, DNSW3CWebHTML5 standardCSS standard Standards define what is needed for interoperabilitySome of the many standards bodies:Interoperability is the ability for an information system to share information with otherinformation systems within an enterpriseNetworking 1025/09/20176 The term bandwidth in two contexts. The bandwidth in hertz, refers to the range of frequencies in acomposite signal or the range of frequencies that a channel can pass. The bandwidth in bits per second, refers to the speed of bittransmission in a channel or link. Often referred to as Capacity. Example The bandwidth of a normal telephone line is 4 kHz. Yet the bandwidthof this line can be up to 56,000 bps.Networking 11 Defines how efficiently channel is being used. A network with bandwidth of 10 Mbps can pass only an average of12,000 frames per minute with each frame carrying an average of10,000 bits. What is the throughput of this network? Solution We can calculate the throughput as The throughput is almost one-fifth of the bandwidth in this case.Networking 1225/09/20177 A typical network involves having users sit at workstations, runningapplications such as word processors or spreadsheet programs. The workstation also is known as a client, which is just a basic computerrunning a client operating system (Windows or Linux). users typically store their files on a central server servers are a special computer that contains more disk space andmemory. Server has special software installed that allows it to functionas a server which provideo file and print services (to allow sharing of files and printers)o web pages to clientso e-mail functionality to the company The term host refers to any computer or device that is connected toa network and sends or receives information on that network. A host can be a server, a workstation, a printer with its own networkcard, or a device such as a router.Networking 1425/09/20178 In a Peer-to-peer NOS users can share resources and files locatedon their computers and access shared resources from others. Thissystem is not based on centralised management of resources. Foreg.: Windows for Workgroup, AppleshareNetworking 15 In a peer-to-peer network, computers function as both clients andservers.Networking 1625/09/20179 In a peer-to-peer network networked computers act as equal partners, or peers individual users control their own resources A peer-to-peer network has no dedicated servers; (a number ofworkstations are connected together for the purpose of sharinginformation or devices),o The Microsoft term for a peer-to-peer network is a workgroup. Be aware thatpeer-to-peer networks typically consist of fewer than 10 systems. Peer-to-peer networks are relatively easy to install and operate A peer-to-peer network works well with 10 or fewer computers peer-to-peer networks do not scale well, their efficiency decreases rapidlyas the number of computers on the network increases Security is difficult to maintainNetworking 17 A peer-to-peer network has no dedicated servers; (a number ofworkstations are connected together for the purpose of sharinginformation or devices), The Microsoft term for a peer-to-peer network is a workgroup. Be awarethat peer-to-peer networks typically consist of fewer than 10 systems. Advantages Low cost– Low cost Easy to set up and install No dedicated administrator required Have control on their own resources and manage their own security May have duplication in resources Disadvantages Limited growth No central organisation Weak security Addition load on computers acting as clients and serversNetworking 1825/09/201710 Client/server NOS allow the network to centralise functions and applications in oneor more dedicated servers. The server is the centre of the network system and allowsaccess to resources and institutes security. The NOS provides the mechanism tointegrate all the components of a network and allows multiple users access theresources simultaneously, regardless of physical location (Ziff, 2011). For eg: NovellNetware, Windows Server, Linux Server (Ubuntu), Unix Server, Mac OS X ServerNetworking 19 A client/server network is built around one or more dedicatedservers. Clients connect to the dedicated servers through thenetworkNetworking 2025/09/201711 In a client/server arrangement, network services are located on adedicated computer called a server The server is a central computer that is continuously available to respondto requests from clients for file, print, and application services Servers are designed to handle requests from many clients simultaneously The aggregation of resources on server systems brings greater security,simpler access and coordinated control, the server introduces a singlepoint of failure One of the most known disadvantage of peer-to-peer is that you can notadminister the network in one single place. data files are stored throughout all the systems user accounts typically are created on all the systemsNetworking 21 One of the most known disadvantage of peer-to-peer is that youcan not administer the network in one single place. user accounts typically are created on all the systems data files are stored throughout all the systems Advantages The data files are stored on the one server. Providing a central point ofadministration All users and permissions stored on server Centralised management of a large numbers of users Strong security that is centralised Capability to grow Capability to create redundant system Disadvantage Expensive Difficult to set up Single point of failure Usually require a network administrator to manageNetworking 2225/09/201712Virtualisation uses special software running on a computerto create a complete guest environmentFunctions as if installed on its own computerThe guest environment is called a virtual machine (VM) Virtualisation is a technology that enables the single physicalinfrastructure to function as a multiple logical infrastructure orresources. Virtualisation is not only limited to the hardware, it cantake many forms such as memory, processor, I/O, network, OS, data,and application. The different forms of Virtualisation will bediscussed in the next section. Before Virtualisation, the single physical infrastructure was used torun a single OS and its applications, which results inunderutilization of resources.Networking 2425/09/201713 Before Virtualisation  After VirtualisationNetworking 25 Industries adopt virtualisation in their organisation because of thefollowing benefits: Better resource utilisation A single hypervisor on a single system can run as many virtual machines as itsRAM, CPU, and drive space allow RAM is almost always the limiting factor A virtual machine that has been shut down is little more than a file sitting on ahard drive Increases ROI Dynamic data centre Supports green IT Eases administration Improves disaster recovery While Virtualisation offers many benefits, it also has some drawbacks: Single point of failure Demands high-end and powerful infrastructure May lead to lower performance Requires specialized skill setNetworking 2625/09/201714 Extra layer of sophisticated programming Manages complex interactions within the host Handles every input and output the OS requests Schedules tasks Allots time and resources A VMware Workstation hypervisor has functions of adding andremoving: Virtual hard drives Virtual network cards Virtual RAM Virtualisation provides virtualized BIOS and System Setup for everyvirtual machineNetworking 27Networking 2825/09/201715 Virtualisation segments host hardware into individual virtualmachines A virtual machine acts like a host system (example: a host Intel systemand a virtual machine that acts like the host Intel system) Emulation converts commands to and from the host into an entirelydifferent platformNetworking 29 Virtualisation example VMware workstation on a Windows system Create a virtual machine running Ubuntu Linux Steps Obtain a copy of VMware Player or Virtual box (free) Select Create a New Virtual Machine Install the operating system; every VM requires a separate, legal copyof WindowsNetworking 3025/09/201716The term used to describe new class of network basedstorage mainly over the InternetPlatform is a collection of integrated networkedhardwareMainly using the internet for communicationAll platforms used via underlying infrastructure andprovides services using API (Applications ProgrammingInterface) and hence hide the complexity The main characteristic of cloud computing Remotely hosted: Services or data are hosted on remote infrastructure. Ubiquitous: Services or data are available from anywhereNetworking 3225/09/201717Software as a Service, Storage as a Service(SaaS): Provider runs own applications oncloud infrastructure.Platform as a service– or PaaS– is a provenmodel for running applications without thehassle of maintaining the hardware andsoftware infrastructure at your company.Infrastructure(laaS): Provides customersaccess to processing, storage, networks orother fundamental resourcesNetworking 33Networking 3425/09/201718Networking 35Networking 3625/09/201719Networking 37This would cost $200/month. This would cost $200/month.NIST Visual Model of Cloud Computing Definition National Institute ofStandards and Technology,Networking 3825/09/201720Networking 39Cloud Deployment Models Private Cloud: Dedicated to one organisation Community Cloud: Several organisations with shared concerns sharecomputer facilities Public Cloud: Available to the public or a large industry group Hybrid Cloud: Two or more clouds (private, community or publicclouds) remain distinct but are bound together by standardized orproprietary technologyMajor Areas of Security Concerns Multi-tenancy: Your app is on same server with other organizations. Need: segmentation, isolation, policy Service Level Agreement (SLA): Defines performance, securitypolicy, availability, backup, location, compliance, audit issues Your Coverage: Total security = your portion + provider portion Responsibility varies for IAAS vs. PAAS vs. SAAS You can transfer security responsibility but not accountabilityNetworking 4025/09/201721Networking 41Challenges: Agility, Green, and Smart GrowthNetworking 4225/09/201722Burgess, M., 2003. Principles of Network and System Administration. 2nd ed.Chichester: John Wiley and Sons Ltd.Hallberg, B., 2005. Networking: A Beginner’s Guide. 4th ed. Osborne: Mcgraw-Hill.Limoncelli, T. & Hogan, C., 2001. The Practice Of System and NetworkAdministration. London: Addison-Wesley.Lowe, D., 2005. Networking All-In-One Desk Reference For Dummies. 2nd ed. NewYork: Hungry Minds Inc..Olifer, N. & Olifer, V., 2005. Computer Networks: Principles, Technologies AndProtocols For Network Design. Chichester: John Wiley And Sons Ltd.Stallings, W., 2003. Data And Computer Communications. 7th ed. New York:Prentice Hall.Subramanian, M., (2000). Network Management: An Introduction to Principles andPractice. Chichester: Addison-Wesley.Tanenbaum, A., 2002. Computer Networks. London: Prentice Hall Ptr.JournalsThe Institute of Engineering and TechnologyNetworking 43


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