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Networking Fundamentals © Ed Green Penn State University

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Networking Fundamentals © Ed Green Penn State University

  1. 1. Networking Fundamentals © Ed Green Penn State University All Rights Reserved
  2. 2. Agenda <ul><li>Objectives </li></ul><ul><li>Basic Terms and Concepts </li></ul><ul><li>Network Topologies </li></ul><ul><li>Devices </li></ul><ul><li>Network Architectures </li></ul><ul><li>Messages </li></ul>
  3. 3. Objectives <ul><li>Introduce networks and networking as concepts </li></ul><ul><li>Introduce common network types </li></ul><ul><li>Introduce different types of network devices </li></ul><ul><li>Introduce different types of network architectures </li></ul><ul><li>Introduce messages and message structures </li></ul>
  4. 4. Networks and Networking <ul><li>Network - a group of interconnected computers . Networks may be classified according to a wide variety of characteristics. (Source: www.wikipedia.org ) </li></ul><ul><ul><li>PAN – Personal Area Network </li></ul></ul><ul><ul><li>LAN – Local Area Network </li></ul></ul><ul><ul><li>MAN – Metropolitan Area Network </li></ul></ul><ul><ul><li>WAN – Wide Area Network </li></ul></ul><ul><li>Networking – the set of processes and devices involved in the use of a network </li></ul>
  5. 5. Classifying Networks <ul><li>Network types </li></ul><ul><ul><li>Open Network – a network that exists in the public space </li></ul></ul><ul><ul><ul><li>Based on designs existing in the public domain </li></ul></ul></ul><ul><ul><ul><li>Available to everyone </li></ul></ul></ul><ul><ul><li>Closed Network – a network that exists only in a non-public space </li></ul></ul><ul><ul><ul><li>Proprietary – available to authenticated users </li></ul></ul></ul><ul><ul><ul><li>May or may not be based on designs existing in public domain </li></ul></ul></ul><ul><li>Standards </li></ul><ul><ul><li>TCP/IP </li></ul></ul><ul><ul><li>Ethernet </li></ul></ul>
  6. 6. Classifying Networks - Topology <ul><li>Bus Topology </li></ul><ul><li>Star Topology </li></ul><ul><li>Distinction </li></ul><ul><ul><li>Not representation </li></ul></ul><ul><ul><li>Communications technique </li></ul></ul>
  7. 7. Methods of Communication <ul><li>Bus Topology From source to destination </li></ul><ul><li>Star Topology Through a central computer ( access point) </li></ul>
  8. 8. Protocols <ul><li>Set of rules governing activities on a network </li></ul><ul><li>Purpose – promote compatibility of network applications using products from different vendors. </li></ul><ul><li>Carrier Sense Multiple Access with Collision Detection (CSMA/CD) – bus topology </li></ul><ul><ul><li>Dictates that a message must be broadcast to every other machine on the network </li></ul></ul><ul><ul><li>Process – </li></ul></ul><ul><ul><ul><li>Wait for inactivity on the bus </li></ul></ul></ul><ul><ul><ul><li>Dispatch message </li></ul></ul></ul><ul><li>Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) – star topology </li></ul><ul><ul><li>Encompassed by IEEE 802.11 standards <WiFi> </li></ul></ul><ul><ul><li>Dispatch messages when ready </li></ul></ul><ul><ul><li>Retransmit when collisions occur </li></ul></ul><ul><ul><li>Give advantage to machines in wait </li></ul></ul><ul><ul><ul><li>Finds silent channel; </li></ul></ul></ul><ul><ul><ul><li>Waits for a period of time; </li></ul></ul></ul><ul><ul><ul><li>Then transmits </li></ul></ul></ul>
  9. 9. Networking Devices <ul><li>Repeater – a device that passes signals back and forth between two busses </li></ul><ul><li>Bridge – a device that passes signals back and forth between two busses based on identified destination of messages </li></ul><ul><li>Switch – a bridge with multiple connections that passes signals back and forth among several busses based on identified destination of messages </li></ul><ul><li>Router – a special purpose computer used for forwarding messages </li></ul><ul><li>i nternet – a network of networks; not I nternet </li></ul><ul><li>Forwarding Table – a structure held by the network manager that keeps track of where each message has been forwarded </li></ul><ul><li>Gateway – internet connection point </li></ul>
  10. 10. Inter-process Communications <ul><li>The interchange of information between two processes </li></ul><ul><ul><li>Clearly defined and described interface </li></ul></ul><ul><ul><li>Exchange of data between two processing entities </li></ul></ul><ul><ul><ul><li>Conversation </li></ul></ul></ul><ul><ul><ul><ul><li>Message sent/acknowledged </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Response replied/acknowledged </li></ul></ul></ul></ul>Process 1 Process 2 Initiating Message Acknowledgement Reply Message Acknowledgement
  11. 11. Inter-process Communications Models <ul><li>Client/server </li></ul><ul><ul><li>Client – the process making the request </li></ul></ul><ul><ul><li>Server – the process satisfying the request </li></ul></ul><ul><li>Peer-to-peer </li></ul><ul><ul><li>Processes that receive and satisfy requests for each other </li></ul></ul>Server serves many clients Communicate as equals on a one – to – one basis
  12. 12. Client/Server Considerations Workstation Clients Processing Server Device Servers Printer Files Network
  13. 13. Client/Server Considerations <ul><li>Thin/Thick – refers to the relative amount of processing that occurs on the device </li></ul><ul><ul><li>Thin client – handles I/O operations for HCI and little other processing </li></ul></ul><ul><ul><li>Thick client – handles a significant amount of processing in addition to I/O operations for HCI </li></ul></ul><ul><li>Process Server – emphasizes executing processing instructions </li></ul><ul><li>Print Server – handles all requirements for hard copy output </li></ul><ul><li>File Server – handles all requirements regarding access to stored data </li></ul><ul><li>Network Server – handles all requirements regarding communications services </li></ul>
  14. 14. Distributed Systems <ul><li>Multiple servers </li></ul><ul><li>Applications execute on more than one server </li></ul><ul><li>Perhaps multiple physical locations </li></ul>Mainframe Router Local Servers Router Local Servers With Clients
  15. 15. Network Connectivity – An Enterprise IT Framework Application Integrator . . . . . . User Interface Security Clients Independent Applications Software that provides “common view” capability <ul><li>Authentication </li></ul><ul><li>Authorization </li></ul>WEB Browser <ul><li>Finance </li></ul><ul><li>Manufacturing </li></ul><ul><li>Sales/Marketing </li></ul><ul><li>Personnel </li></ul><ul><li>Engineering </li></ul>
  16. 16. e-World Concept of Operations <ul><li>e-Process begins with a buyer and a seller </li></ul><ul><ul><li>Goods/services wanted and available </li></ul></ul><ul><li>GLOBAL EXCHANGE facilitates the electronic transaction </li></ul><ul><li>Seller’s catalog reviewed by buyer </li></ul><ul><ul><li>Needed items available </li></ul></ul><ul><li>Purchase order prepared and transmitted to global exchange </li></ul><ul><li>Global exchange routes to seller </li></ul><ul><li>Order entry prepared </li></ul><ul><li>Production schedule established or updated </li></ul><ul><li>Inventory checked; replenishment ordered </li></ul><ul><li>Manufacturing resources assigned </li></ul><ul><li>Labor availability checked </li></ul><ul><ul><li>Resources assigned OR HR to staff prepared </li></ul></ul><ul><li>Sub-assemblies and other resources reserved </li></ul><ul><li>Production package prepared </li></ul><ul><ul><li>Bill of materials </li></ul></ul><ul><ul><li>Manufacturing/assembly instructions </li></ul></ul><ul><ul><li>Drawings/blueprints </li></ul></ul>
  17. 17. e-World Concept of Operations (continued) <ul><li>Production process is monitored </li></ul><ul><li>Labor time & attendance is recorded </li></ul><ul><li>Test results and quality analysis recorded </li></ul><ul><li>Shipping is scheduled </li></ul><ul><li>Customer Service is advised </li></ul><ul><li>Billing is notified </li></ul><ul><ul><li>Customer billing is prepared </li></ul></ul><ul><li>Order is shipped </li></ul><ul><li>Order is received </li></ul><ul><li>Receiving inspection conducted; test results recorded </li></ul><ul><li>Bill is received </li></ul><ul><li>Payment is made </li></ul><ul><li>Questions arise </li></ul><ul><li>Supplier customer service is contacted </li></ul><ul><ul><li>Call is recorded </li></ul></ul><ul><ul><li>Question is researched in the product reference materials </li></ul></ul><ul><ul><li>Answer is provided </li></ul></ul>
  18. 18. Enterprise Inter-connectivity Application Integrator . . . . . . User Interface Security Application Integrator . . . . . . User Interface Security Application Integrator . . . . . . User Interface Security Application Integrator . . . . . . User Interface Security Application Integrator . . . . . . User Interface Security
  19. 19. Messages <ul><li>Basic unit of communication on a network </li></ul><ul><li>Defined structure </li></ul>
  20. 20. Message Structure Message Header Includes destination Identifies source Identifies message (type) Message Trailer Indicates end of message Message Contents Must be defined in such a way that it is understood by BOTH sender AND receiver
  21. 21. Messaging Infrastructure – Message Format Abstraction Message Properties Destination Delivery Mode Message ID Timestamp Correlation ID Reply To Redelivered Type Expiration Priority
  22. 22. Network Architecture
  23. 23. Network Architecture – Backbone of the Architecture <ul><li>Explains the communications configuration </li></ul><ul><ul><li>What elements will be used for communication? </li></ul></ul><ul><li>Defines the topology of the architecture </li></ul><ul><ul><li>Where will these communications elements be located? </li></ul></ul><ul><li>Describes the routing </li></ul><ul><ul><li>How will data get from one node to the next? </li></ul></ul><ul><ul><li>Considers alternatives </li></ul></ul><ul><ul><ul><li>Transportation model </li></ul></ul></ul><ul><li>Addresses protocols </li></ul><ul><ul><li>What is the communications mechanism? </li></ul></ul><ul><ul><li>Are multiple protocols used and is translation needed? </li></ul></ul>
  24. 24. Transportation Model <ul><li>“ Import” from Operations Research </li></ul><ul><ul><li>Developed originally to optimize routing of freight hauling vehicles (trains and trucks) </li></ul></ul><ul><ul><li>Represents a realistic algorithm set that directs transports to the path of least obstruction </li></ul></ul><ul><ul><ul><li>Minimum Traffic </li></ul></ul></ul><ul><ul><ul><li>Minimum delays </li></ul></ul></ul><ul><li>Example </li></ul><ul><ul><li>A shipment of Volkswagens arrives at the Port of Baltimore. These cars are to be shipped to various locations across the United States, including Pittsburgh, Fort Wayne, Kansas City, Denver, and Missoula. What is the optimal route? </li></ul></ul><ul><ul><li>At each city, what is the best route to the next stop based on all routing conditions? </li></ul></ul><ul><ul><ul><li>Traffic </li></ul></ul></ul><ul><ul><ul><li>Construction </li></ul></ul></ul><ul><ul><ul><li>Weather </li></ul></ul></ul>
  25. 25. Applying the Transportation Model <ul><li>NORNE , a large energy services company, has business centers located in Baltimore, Pittsburgh, Fort Wayne, Kansas City, Denver, and Missoula. Payroll for the entire company is processed at the Baltimore computer center. Individual time and attendance data is collected for employees at individual locations and then forwarded to Baltimore. Since payroll is a time critical application, time and attendance data must arrive in a timely manner. </li></ul>
  26. 26. Applying the Transportation Model Which route will the data take?
  27. 27. Applying the Transportation Model <ul><li>Route not predictable in advance </li></ul><ul><ul><li>Will vary based on conditions </li></ul></ul><ul><li>Will follow “path of least resistance” </li></ul><ul><ul><li>ALL network managers work to minimize latency and maximize throughput </li></ul></ul><ul><li>Data will depart from a given node with </li></ul><ul><ul><li>Next node identified </li></ul></ul><ul><ul><li>General itinerary </li></ul></ul><ul><li>General itinerary identified upon arrival at each destination </li></ul><ul><ul><li>Routing re-planned should conditions warrant </li></ul></ul>
  28. 28. Components of Network Architectures <ul><li>Routers – a physical or logical device that determines the next network point to which a packet should be forwarded </li></ul><ul><ul><li>Connected to at least two networks </li></ul></ul><ul><ul><li>Decision based on current understanding of network state </li></ul></ul><ul><ul><ul><li>Table of routing alternatives and current conditions </li></ul></ul></ul><ul><ul><li>Located at any gateway </li></ul></ul><ul><li>Gateway – the place where one network or network segment meets another </li></ul><ul><li>Switch – a physical or logical device that redirects a packet from one network segment to another </li></ul>
  29. 29. Components of Network Architecture <ul><li>Bandwidth – the capacity of a network measured in terms of throughput rate </li></ul><ul><ul><li>Gigabits per second </li></ul></ul><ul><li>TCP/IP communications language of the internet </li></ul><ul><li>Packet – the “data unit” that is transported from one node to another </li></ul>
  30. 30. Network Architecture – Showing the Components Mainframe Router Local Servers Router Local Servers With Clients
  31. 31. Network Architecture – Showing the Topology Mainframe Router Local Servers Router Local Servers With Clients
  32. 32. Networks – Discussion Example ISP Local Web Sites Track an Internet search

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