networking fundamentals © ed green penn state university
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Networking Networking FundamentalsFundamentals
© Ed Green© Ed Green Penn State UniversityPenn State University All Rights ReservedAll Rights Reserved
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AgendaAgenda ObjectivesObjectives Basic Terms and ConceptsBasic Terms and Concepts Network TopologiesNetwork Topologies DevicesDevices Network ArchitecturesNetwork Architectures MessagesMessages
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ObjectivesObjectives Introduce Introduce networks networks and and networkingnetworking
as conceptsas concepts Introduce common network typesIntroduce common network types Introduce different types of network Introduce different types of network
devicesdevices Introduce different types of network Introduce different types of network
architecturesarchitectures Introduce messages and message Introduce messages and message
structuresstructures
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Networks and Networks and NetworkingNetworking NetworkNetwork - a group of interconnected - a group of interconnected
computerscomputers. Networks may be . Networks may be classified according to a wide variety classified according to a wide variety of characteristics. of characteristics. (Source: (Source: www.wikipedia.orgwww.wikipedia.org ) )
PAN – Personal Area NetworkPAN – Personal Area Network LAN – Local Area NetworkLAN – Local Area Network MAN – Metropolitan Area NetworkMAN – Metropolitan Area Network WAN – Wide Area NetworkWAN – Wide Area Network
NetworkingNetworking – the set of processes and – the set of processes and devices involved in the use of a devices involved in the use of a networknetwork
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Classifying NetworksClassifying Networks Network typesNetwork types
OpenOpen Network – a network that exists in the public Network – a network that exists in the public space space
Based on designs existing in the public domainBased on designs existing in the public domain Available to everyoneAvailable to everyone
ClosedClosed Network – a network that exists Network – a network that exists onlyonly in a in a non-public spacenon-public space
Proprietary – available to authenticated usersProprietary – available to authenticated users May or may not be based on designs existing in May or may not be based on designs existing in
public domainpublic domain StandardsStandards
TCP/IPTCP/IP EthernetEthernet
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Classifying Networks - Classifying Networks - TopologyTopology Bus TopologyBus Topology Star TopologyStar Topology
Distinction Distinction Not representationNot representation Communications techniqueCommunications technique
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Methods of Methods of CommunicationCommunication Bus TopologyBus Topology
From source to From source to destinationdestination
Star TopologyStar Topology
Through a central Through a central computer (computer (access point)access point)
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ProtocolsProtocols Set of rules governing activities on a networkSet of rules governing activities on a network Purpose – promote compatibility of network applications Purpose – promote compatibility of network applications
using products from different vendors.using products from different vendors. Carrier Sense Multiple Access with Collision Detection Carrier Sense Multiple Access with Collision Detection
(CSMA/CD) – bus topology(CSMA/CD) – bus topology Dictates that a message Dictates that a message must bemust be broadcast to every other broadcast to every other
machine on the networkmachine on the network Process –Process –
Wait for inactivity on the busWait for inactivity on the bus Dispatch messageDispatch message
Carrier Sense Multiple Access with Collision Avoidance Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) – star topology(CSMA/CA) – star topology Encompassed by IEEE 802.11 standards <WiFi>Encompassed by IEEE 802.11 standards <WiFi> Dispatch messages when readyDispatch messages when ready Retransmit when collisions occurRetransmit when collisions occur Give advantage to machines in waitGive advantage to machines in wait
Finds silent channel; Finds silent channel; Waits for a period of time; Waits for a period of time; Then transmitsThen transmits
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Networking DevicesNetworking Devices Repeater – a device that passes signals back and Repeater – a device that passes signals back and
forth between two bussesforth between two busses Bridge – a device that passes signals back and forth Bridge – a device that passes signals back and forth
between two busses based on identified destination between two busses based on identified destination of messagesof messages
Switch – a bridge with multiple connections that Switch – a bridge with multiple connections that passes signals back and forth among several busses passes signals back and forth among several busses based on identified destination of messagesbased on identified destination of messages
Router – a special purpose computer used for Router – a special purpose computer used for forwarding messagesforwarding messages
iinternet – a network of networks; not nternet – a network of networks; not IInternetnternet Forwarding Table – a structure held by the network Forwarding Table – a structure held by the network
manager that keeps track of where each message manager that keeps track of where each message has been forwardedhas been forwarded
Gateway – internet connection pointGateway – internet connection point
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Inter-process Inter-process CommunicationsCommunications The interchange of information The interchange of information
between two processesbetween two processes Clearly defined and described interfaceClearly defined and described interface Exchange of data between two processing Exchange of data between two processing
entitiesentities ConversationConversation
Message sent/acknowledgedMessage sent/acknowledged Response replied/acknowledgedResponse replied/acknowledged
Process 1Process 1 Process 2Process 2
Initiating MessageInitiating Message
Acknowledgement Acknowledgement
Reply MessageReply Message
Acknowledgement Acknowledgement
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Inter-process Inter-process Communications ModelsCommunications Models Client/serverClient/server
Client – the process making the requestClient – the process making the request Server – the process satisfying the requestServer – the process satisfying the request
Peer-to-peerPeer-to-peer Processes that receive and satisfy requests for Processes that receive and satisfy requests for
each othereach other
Server Server serves many serves many clientsclients
Communicate as equals on a one – to – one basisCommunicate as equals on a one – to – one basis
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Client/Server Client/Server ConsiderationsConsiderations
WorkstationWorkstationClientsClients
ProcessingProcessingServerServer
DeviceDeviceServersServers
PrinterPrinter
FilesFiles
NetworkNetwork
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Client/Server Client/Server ConsiderationsConsiderations Thin/Thick – refers to the relative amount of Thin/Thick – refers to the relative amount of
processing that occurs on the deviceprocessing that occurs on the device Thin client – handles I/O operations for HCI and Thin client – handles I/O operations for HCI and
little other processinglittle other processing Thick client – handles a significant amount of Thick client – handles a significant amount of
processing in addition to I/O operations for HCIprocessing in addition to I/O operations for HCI Process Server – emphasizes executing Process Server – emphasizes executing
processing instructionsprocessing instructions Print Server – handles all requirements for Print Server – handles all requirements for
hard copy outputhard copy output File Server – handles all requirements File Server – handles all requirements
regarding access to stored dataregarding access to stored data Network Server – handles all requirements Network Server – handles all requirements
regarding communications servicesregarding communications services
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Distributed SystemsDistributed Systems Multiple serversMultiple servers Applications execute on more than one serverApplications execute on more than one server Perhaps multiple physical locationsPerhaps multiple physical locations
Mainframe Router
LocalServers
Router
Local ServersWith Clients
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Network Connectivity – An Network Connectivity – An Enterprise IT FrameworkEnterprise IT Framework
Application Integrator
. . .. . .
. . .. . .
User Interface
SecuritySecurity
ClientsClients
IndependentIndependentApplicationsApplications
Software thatSoftware thatprovides “commonprovides “commonview” capabilityview” capability
•AuthenticationAuthentication•AuthorizationAuthorization
WEB BrowserWEB Browser
•FinanceFinance•ManufacturingManufacturing•Sales/MarketingSales/Marketing•PersonnelPersonnel•EngineeringEngineering
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e-World Concept of e-World Concept of OperationsOperations e-Process begins with a e-Process begins with a
buyer and a sellerbuyer and a seller Goods/services wanted Goods/services wanted
and availableand available GLOBAL EXCHANGE GLOBAL EXCHANGE
facilitates the electronic facilitates the electronic transactiontransaction
Seller’s catalog reviewed Seller’s catalog reviewed by buyerby buyer Needed items availableNeeded items available
Purchase order prepared Purchase order prepared and transmitted to and transmitted to global exchangeglobal exchange
Global exchange routes Global exchange routes to sellerto seller
Order entry preparedOrder entry prepared
Production schedule Production schedule established or updatedestablished or updated
Inventory checked; Inventory checked; replenishment orderedreplenishment ordered
Manufacturing resources Manufacturing resources assignedassigned
Labor availability checkedLabor availability checked Resources assignedResources assigned
OR ORHR to staff preparedHR to staff prepared
Sub-assemblies and other Sub-assemblies and other resources reservedresources reserved
Production package Production package preparedprepared Bill of materialsBill of materials Manufacturing/assembly Manufacturing/assembly
instructionsinstructions Drawings/blueprintsDrawings/blueprints
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e-World Concept of e-World Concept of OperationsOperations (continued) (continued)
Production process is Production process is monitoredmonitored
Labor time & attendance Labor time & attendance is recordedis recorded
Test results and quality Test results and quality analysis recordedanalysis recorded
Shipping is scheduledShipping is scheduled Customer Service is Customer Service is
advisedadvised Billing is notifiedBilling is notified
Customer billing is Customer billing is preparedprepared
Order is shippedOrder is shipped
Order is receivedOrder is received Receiving inspection Receiving inspection
conducted; test results conducted; test results recordedrecorded
Bill is receivedBill is received Payment is madePayment is made Questions ariseQuestions arise Supplier customer Supplier customer
service is contactedservice is contacted Call is recordedCall is recorded Question is researched Question is researched
in the product reference in the product reference materialsmaterials
Answer is providedAnswer is provided
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Enterprise Inter-Enterprise Inter-connectivityconnectivity
Application Integrator
. . .. . .
. . .. . .User Interface
SecuritySecurity
Application Integrator
. . .. . .
. . .. . .User Interface
SecuritySecurity
Application Integrator
. . .. . .
. . .. . .User Interface
SecuritySecurity
Application Integrator
. . .. . .
. . .. . .User Interface
SecuritySecurityApplication Integrator
. . .. . .
. . .. . .User Interface
SecuritySecurity
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MessagesMessages Basic unit of communication on a Basic unit of communication on a
networknetwork Defined structureDefined structure
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Message StructureMessage Structure
Message HeaderMessage Header Includes destinationIncludes destination Identifies sourceIdentifies source Identifies message (type)Identifies message (type)
Message TrailerMessage Trailer Indicates end of messageIndicates end of message
Message ContentsMessage Contents Must be defined in such a way that Must be defined in such a way that it is understood by it is understood by BOTHBOTH sender sender ANDAND receiver receiver
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Messaging Infrastructure – Messaging Infrastructure – Message Format Message Format
AbstractionAbstractionDestination
Delivery Mode
Message ID
Timestamp
Correlation ID
Reply To
Redelivered
Type
Expiration
Priority
Message Properties
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Network ArchitectureNetwork Architecture
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Network Architecture – Network Architecture – Backbone of the Backbone of the
ArchitectureArchitecture Explains the communications configurationExplains the communications configuration
What elements will be used for communication?What elements will be used for communication? Defines the topology of the architectureDefines the topology of the architecture
Where will these communications elements be Where will these communications elements be located?located?
Describes the routingDescribes the routing How will data get from one node to the next?How will data get from one node to the next? Considers alternativesConsiders alternatives
Transportation modelTransportation model Addresses protocolsAddresses protocols
What is the communications mechanism?What is the communications mechanism? Are multiple protocols used and is translation Are multiple protocols used and is translation
needed?needed?
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Transportation ModelTransportation Model ““Import” from Operations ResearchImport” from Operations Research
Developed originally to optimize routing of freight Developed originally to optimize routing of freight hauling vehicles (trains and trucks)hauling vehicles (trains and trucks)
Represents a realistic algorithm set that directs Represents a realistic algorithm set that directs transports to the path of least obstructiontransports to the path of least obstruction
Minimum TrafficMinimum Traffic Minimum delaysMinimum delays
ExampleExample A shipment of Volkswagens arrives at the Port of A shipment of Volkswagens arrives at the Port of
Baltimore. These cars are to be shipped to various Baltimore. These cars are to be shipped to various locations across the United States, including locations across the United States, including Pittsburgh, Fort Wayne, Kansas City, Denver, and Pittsburgh, Fort Wayne, Kansas City, Denver, and Missoula. What is the optimal route?Missoula. What is the optimal route?
At each city, what is the best route to the next stop At each city, what is the best route to the next stop based on all routing conditions? based on all routing conditions?
TrafficTraffic ConstructionConstruction WeatherWeather
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Applying the Applying the Transportation ModelTransportation Model
NORNENORNE, a large energy services company, , a large energy services company, has business centers located in Baltimore, has business centers located in Baltimore, Pittsburgh, Fort Wayne, Kansas City, Pittsburgh, Fort Wayne, Kansas City, Denver, and Missoula. Payroll for the Denver, and Missoula. Payroll for the entire company is processed at the entire company is processed at the Baltimore computer center. Individual Baltimore computer center. Individual time and attendance data is collected for time and attendance data is collected for employees at individual locations and then employees at individual locations and then forwarded to Baltimore. Since payroll is a forwarded to Baltimore. Since payroll is a time critical application, time and time critical application, time and attendance data must arrive in a timely attendance data must arrive in a timely manner.manner.
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Applying the Applying the Transportation ModelTransportation Model
Which route will the data take?
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Applying the Applying the Transportation ModelTransportation Model
Route not predictable in advance Route not predictable in advance Will vary based on conditionsWill vary based on conditions
Will follow “path of least resistance”Will follow “path of least resistance” ALLALL network managers work to minimize network managers work to minimize
latency and maximize throughputlatency and maximize throughput Data will depart from a given node Data will depart from a given node withwith
Next node identifiedNext node identified General itineraryGeneral itinerary
General itinerary identified upon arrival at General itinerary identified upon arrival at each destinationeach destination Routing re-planned should conditions warrantRouting re-planned should conditions warrant
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Components of Network Components of Network ArchitecturesArchitectures
Routers – a physical or logical device that Routers – a physical or logical device that determines the next network point to which determines the next network point to which a packet should be forwardeda packet should be forwarded Connected to at least two networksConnected to at least two networks Decision based on current understanding of Decision based on current understanding of
network statenetwork state Table of routing alternatives and current Table of routing alternatives and current
conditionsconditions Located at any gatewayLocated at any gateway
Gateway – the place where one network or Gateway – the place where one network or network segment meets anothernetwork segment meets another
Switch – a physical or logical device that Switch – a physical or logical device that redirects a packet from one network redirects a packet from one network segment to anothersegment to another
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Components of Network Components of Network ArchitectureArchitecture
Bandwidth – the capacity of a network Bandwidth – the capacity of a network measured in terms of throughput ratemeasured in terms of throughput rate Gigabits per Gigabits per secondsecond
TCP/IP communications language of TCP/IP communications language of the internetthe internet
Packet – the “data unit” that is Packet – the “data unit” that is transported from one node to anothertransported from one node to another
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Network Architecture – Network Architecture – Showing the ComponentsShowing the Components
Mainframe Router
LocalServers
Router
Local ServersWith Clients
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Network Architecture – Network Architecture – Showing the TopologyShowing the Topology
Mainframe Router
LocalServers
Router Local Servers
With Clients
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Networks – Discussion Networks – Discussion ExampleExample
ISPISP
Local W
eb
Sit
es
Local W
eb
Sit
es
Track an Internet searchTrack an Internet search