Instructor Information
          Instructor: Dr. Wenbing Zhao
              Office: SH317
              Email: w.zhao1@csuohio.edu 
              Office hours: W M 4-6pm and by appointment
        09/02/2022                          EEC-484/584: Computer Networks                        Wenbing Zhao
        What is a Computer 
        Network?
     A group of computers inter-connected together
                                       Local Area Network
                        What makes this course so 
                            relevant is the Internet 
        09/02/2022                          EEC-484/584: Computer Networks                        Wenbing Zhao
     Internet: “Nuts and Bolts” 
     View
          PC          Millions of connected                                  Mobile network
           server         computing devices: hosts                                                      Global ISP
                          = end systems 
           wireless         Running network apps
           laptop
            cellular                                                          Home network
            handheld •     Communication links
                                                                                                     Regional ISP
                             – Fiber, copper, radio, 
                                 satellite
                 access      – Transmission rate = 
                 points                                                               Institutional network
                wired            bandwidth
                links
                       •    Routers: forward 
                            packets (chunks of 
          router            data)
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    Internet: “Nuts and Bolts” 
    View
     Protocols control sending,               Mobile network
       receiving of msgs                                      Global ISP
        e.g., TCP, IP, HTTP, Skype,  
          Ethernet
     Internet: “network of networks”          Home network
        loosely hierarchical                               Regional ISP
        public Internet versus private 
          intranet
     Internet standards                           Institutional network
        RFC: Request for comments
        IETF: Internet Engineering 
          Task Force
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     What’s a Protocol?
      Human Protocols:                Network Protocols:
       “what’s the time?”             machines rather than 
       “I have a question”              humans
       introductions                  all communication activity 
                                         in Internet governed by 
                                         protocols
      … specific msgs sent
      … specific actions taken        protocols define format, order of msgs sent 
        when msgs received, or           and received among network entities, 
        other events                    and actions taken on msg transmission, 
                                                     receipt 
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