Network Management

COMP4690, by Dr Xiaowen Chu, HKBU1Network ManagementChapter 1Networking Components1COMP4690, by Dr Xiaowen Chu, HKBU2OutlineData CommunicationsNetworkingOSI Reference ModelTCP/IP Protocol ArchitectureNetworking Components

2COMP4690, by Dr Xiaowen Chu, HKBU3Data CommunicationsData communications deals with the transmission of signals in a reliable and efficient manner. Topics covered include signal transmission, transmission media, signal encoding, interfacing, data link control, and multiplexing.3COMP4690, by Dr Xiaowen Chu, HKBU4A Communications ModelPurpose of Communications Exchange of data (information) between entitiesKey elementsSourceGenerates data to be transmittedTransmitterConverts data into transmittable signalsTransmission SystemCarries dataReceiverConverts received signal into dataDestinationTakes incoming data4COMP4690, by Dr Xiaowen Chu, HKBU5A Communications Model

5COMP4690, by Dr Xiaowen Chu, HKBU6NetworkingPoint to point communication is not usually practicalDevices are too far apartLarge set of devices would need impractical number of connectionsSolution is a communications networkLocal Area Network (LAN)Metropolitan Area Network (MAN)Wide Area Network (WAN)6COMP4690, by Dr Xiaowen Chu, HKBU7Local Area NetworksSmaller scopeOffice, Building, CampusUsually owned by same organization as attached devicesData rates are highEthernet dominates the marketEthernet vs. Token RingEthernet vs. ATMWireless LAN is now very popular7COMP4690, by Dr Xiaowen Chu, HKBU8Metropolitan Area NetworksLarge areaMiddle ground between LAN and WANPrivate or public networkHigh speed8COMP4690, by Dr Xiaowen Chu, HKBU9Wide Area NetworksCover a large geographical areaConsists of a set of interconnected switching nodesAlternative technologiesCircuit switchingTelephone networkPacket switchingX.25Frame relayAsynchronous Transfer Mode (ATM)Internet9COMP4690, by Dr Xiaowen Chu, HKBU10Digital NetworkFive Important ComponentsTransmission (electrical, optical, wireless)Routing and SwitchingCircuit switching (telephone network)Packet switchingVirtual-circuit (X.25, Frame Relay, ATM)Datagram (Internet)SignalingAccessxDSL, Cable Modem, WiFi/WiMax, LANNetwork Management

10COMP4690, by Dr Xiaowen Chu, HKBU11Digital Network

11COMP4690, by Dr Xiaowen Chu, HKBU12Protocol ArchitectureA protocol architecture is the layered structure of hardware and software that supports the exchange of data between systems and supports distributed applications, such as electronic mail and file transfer.At each layer of a protocol architecture, one or more common protocols are implemented in communicating systems. Each protocol provides a set of rules for the exchange of data between systems.12COMP4690, by Dr Xiaowen Chu, HKBU13OSI Reference ModelOSI: Open System InterconnectionA 7-layer modelEach layer performs a subset of the required communication functionsEach layer relies on the next lower layer to perform more primitive functionsEach layer provides services to the next higher layerChanges in one layer should not require changes in other layers13COMP4690, by Dr Xiaowen Chu, HKBU14OSI Reference ModelApplication: supporting network applications - FTP, SMTP, HTTP, etc.Presentation: handle different data representations (e.g., encryption)Session: connections between appsTransport: host-host - TCP, UDPNetwork: routing of datagrams from source to dest - IP, routing protocolsLink: data transfer between adjacent network elements - PPP, EthernetPhysical: bits on the wireApplication (7)Presentation (6)Session (5)Transport (4)Network (3)Data link (2)Physical (1)14COMP4690, by Dr Xiaowen Chu, HKBU15OSI LayersPhysicalPhysical interface between devicesMechanicalElectricalFunctionalProceduralData LinkMeans of activating, maintaining and deactivating a reliable linkError detection and controlHigher layers may assume error free transmission15COMP4690, by Dr Xiaowen Chu, HKBU16OSI LayersNetworkTransport of informationHigher layers do not need to know about underlying technologyNot needed on direct linksTransportExchange of data between end systemsError freeIn sequenceNo lossesNo duplicatesQuality of service16COMP4690, by Dr Xiaowen Chu, HKBU17OSI LayersSessionControl of dialogues between applicationsDialogue disciplineGroupingRecoveryPresentationData formats and codingData compressionEncryptionApplicationMeans for applications to access OSI environment17COMP4690, by Dr Xiaowen Chu, HKBU18TCP/IP Protocol ArchitectureDeveloped by the US Defense Advanced Research Project Agency (DARPA) for its packet switched network (ARPANET)Used by the global InternetNo official model but a working one.Application layerTransport layerInternet layer (or Network Layer)Network access layer (or Link Layer)Physical layer18COMP4690, by Dr Xiaowen Chu, HKBU19TCP/IP Protocol Architecture

19COMP4690, by Dr Xiaowen Chu, HKBU20Physical LayerPhysical interface between data transmission device (e.g. computer) and transmission medium or networkCharacteristics of transmission mediumSignal levelsData ratesetc.20COMP4690, by Dr Xiaowen Chu, HKBU21Network Access LayerExchange of data between end system and networkDestination address provisionInvoking services like priority

21COMP4690, by Dr Xiaowen Chu, HKBU22Internet LayerSystems may be attached to different networksRouting functions across multiple networksImplemented in end systems and routers

22COMP4690, by Dr Xiaowen Chu, HKBU23Transport LayerUsually there is a requirement of reliable delivery of data:Error-free (Packets could be lost in the network!)Ordering of deliveryTCP is mainly designed for this purpose.Another transport layer protocol in TCP/IP protocol architecture is UDP.

23COMP4690, by Dr Xiaowen Chu, HKBU24Application LayerSupport for user applicationse.g. FTP, TELNET, SMTP, HTTP, SNMP

24COMP4690, by Dr Xiaowen Chu, HKBU25TCP/IP Protocols

25COMP4690, by Dr Xiaowen Chu, HKBU26OSI vs. TCP/IP

26COMP4690, by Dr Xiaowen Chu, HKBU27Network Components

27COMP4690, by Dr Xiaowen Chu, HKBU28Repeater HubRepeater is a physical layer deviceAmplifies the signalCan extend the length of the LANHub is a repeater with multiple I/O portsA physical layer deviceDemo network has a hub in subnet 2Sometimes called repeater hubRepeaters and Hubs work at Physical layer.The bandwidth is shared by all attached devices.28COMP4690, by Dr Xiaowen Chu, HKBU29Repeater Hub: topology

29COMP4690, by Dr Xiaowen Chu, HKBU30Repeater Hub: schematic

30COMP4690, by Dr Xiaowen Chu, HKBU31Bridge and SwitchBridge is a Link layer deviceOnly forwards frame onto appropriate link(s)Transparent since self-learningSometimes called bridge hubA switch is a multiport bridgeSo a switch is a layer 2 deviceIn switched Ethernet, can have simultaneous comm. between hosts on LAN without collisionsSometimes called switch hub31COMP4690, by Dr Xiaowen Chu, HKBU32Bridge Hub

32COMP4690, by Dr Xiaowen Chu, HKBU33Multiport Bridge Hub

33COMP4690, by Dr Xiaowen Chu, HKBU34Cisco Catalyst 2950 Series Switches

34COMP4690, by Dr Xiaowen Chu, HKBU35PerformanceSome main performance metrics:Backplane bandwidth: measured in bps (bits per second)Forwarding capability: measured in pps (packets per second)Number of MAC address

13.6 Gbps switching fabric Cisco Catalyst 2955T-12: 6.4 Gbps maximum forwarding bandwidth Cisco Catalyst 2955C-12: 2.8 Gbps maximum forwarding bandwidth

(Forwarding rates based on 64-byte packets)Cisco Catalyst 2955T-12: 4.8 Mpps wire speed forwarding rate Cisco Catalyst 2955C-12: 2.0 Mpps wire speed forwarding rate

Configurable up to 8000 MAC addresses

35COMP4690, by Dr Xiaowen Chu, HKBU36Cisco Catalyst 6500 Series Switches

36COMP4690, by Dr Xiaowen Chu, HKBU37PerformanceBackplane Bandwidth32-Gbps shared bus256-Gbps switch fabric720-Gbps switch fabricLayer 3 Forwarding PerformanceCisco Catalyst 6500 Supervisor Engine 1A Multilayer Switch Feature Card (MSFC2): 15 MppsCatalyst 6500 Supervisor Engine 2 MSFC2: up to 210 MppsCatalyst 6500 Supervisor Engine 32 MSFC2a: 15 MppsCatalyst 6500 Supervisor Engine 720: up to 400 Mpps37COMP4690, by Dr Xiaowen Chu, HKBU38IP RouterRoutersLayer 3 devicesLike bridges/switches, routers isolate collision domainsRouters also isolate broadcast domainsRouting tables use IP addressFor small network, static table is OKFor larger network, use RIP, OSPF, etc.38COMP4690, by Dr Xiaowen Chu, HKBU39Router: Framework

39COMP4690, by Dr Xiaowen Chu, HKBU40Bus-based Router

40COMP4690, by Dr Xiaowen Chu, HKBU41Switch-based Router

41COMP4690, by Dr Xiaowen Chu, HKBU42Cisco 7600 Series Routers

42COMP4690, by Dr Xiaowen Chu, HKBU43PerformanceModel7603 7606 7609 7613 Slots36913ForwardingPerformance15 Mpps30 Mpps30 Mpps30 MppsBackplane Capacity240 Gbps480 Gbps720 Gbps720 Gbps43COMP4690, by Dr Xiaowen Chu, HKBU44Cisco 12000 Series Routers

44COMP4690, by Dr Xiaowen Chu, HKBU45PerformanceModleSwitching Capacity 12816 1.28 Tbps12810 800 Gbps12416 320 Gbps12410 200 Gbps12406 120 Gbps12404 80 Gbps12016 80 Gbps12010 50 Gbps12006 30 Gbps45COMP4690, by Dr Xiaowen Chu, HKBU46Junipers RouterPlatformThroughputMax Forwarding RateT320320 Gbps385 MppsT640640Gbps

770 Mpps46COMP4690, by Dr Xiaowen Chu, HKBU47ProbesProbesGather information and pass it to management stationManagement station analyzes the network trafficProbe is also called remote monitorIn demo network, Probe 1 can monitor two segments simultaneously because it has two monitor ports.Also there are software-based probes47COMP4690, by Dr Xiaowen Chu, HKBU48ReferencesJ. Richard Durke, Network Management, Concepts and Practice: A Hands-on Approach, Prentice Hall, 2004.William Stallings, Data and Computer Communications, 7th Edition, Prentice Hall, 2004.J. F. Kurose and K. W. Ross, Computer Networking: A Top-Down Approach Featuring the Internet, 3nd Edition, Prentice Hall, 2005.Fred Halsall, Computer Networking and the Internet, 5th Edition, Addison Wesley, 2005.http://www.cisco.comhttp://www.juniper.net

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PSTN

Probe = Remote Monitor

WS = Workstation

PSTN = Public Switched Telephone

Network

NMS = Network Management System

= network links

= management links

Router

10BASE2 Segment

WS 1

NMS

LAN

SUBNET 1

SUBNET 2

SWITCH 2

SWITCH 1

PROBE 1

SERVER

WS 2

PROBE 2

HUB

WAN

ROUTER