Web Media Overview

Outline of Computer Communications Topics

• Terminology
  • Ports
    • hardware
    • software/virtual
  • Connection media
  • Data Rates
  • Protocols
• Point-to-point connections
  • Hardwired serial line
  • Dial-up
    • BBS (Bulletin Board Systems)
• Networks
  • Local-area (LAN)
    • connection hardware
      • dial-in access
      • LocalTalk
      • Ethernet
        • Thick, Thin coax
        • Twisted-pair (10 base T)
        • Fast Ethernet (100 base T)
        • Megabit Ethernet
      • Token-ring
      • FDDI (Fiber Distributed Data Interconnect)
      • ATM (Asynchronous Transfer Mode)
    • software protocols
      • AppleTalk
        • LocalTalk, EtherTalk, TokenTalk, ARA (Apple Remote Access Protocol)
      • IPX (Novell Netware)
      • TCP/IP (Transmission Control Protocol/Internet Protocol)
        • These two protocols are the foundation of UNIX LAN communications, as well as communications over the Internet.
        • Respective purpose: parcel out data into "packets", and route the packets in the most efficient manner to their destination.
        • UDP (User Datagram Protocol)
          • Faster, less reliable replacement for TCP--used in real-time applications such as streaming video.
  • Wide-area (WAN)
    • LAN hardware routed to long-distance links
    • LAN protocols scaled up to large decentralized networks
    • the Internet
      • Overview
        • Loosely-organized group of interconnected computers, spanning the globe
        • Store-and-forward
        • Redundant routes
      • Addressing
        • IP numbers
        • domain names
        • URL (Universal Resource Locator)
      • Access
        • Physical connection
          • Part-time connection
            • Symmetrical (same bandwidth incoming and outgoing)
              • POTS (Plain-old Telephone System)
                • Modem (Modulator-Demodulator)
              • ISDN (Integrated Services Digital Network)
              • symmetrical versions of xDSL (Digital Subscriber Line)
            • Asymmetrical
              • Cable modems
              • ADSL (Asymmetrical DSL)
          • Full-time connection
            • ISDN "nailed up"
            • xDSL ?
            • Frame relay
              • 56K
              • T1
              • T3
        • Account type
          • Mail-only
          • Shell
          • SLIP (Serial Line IP) or PPP (Point-to-Point Protocol)
            • MLP (Multilink PPP)--ISDN with multiple B channels
      • Services
        • Mail
          • outgoing--SMTP (Simple Mail Transfer Protocol)
          • incoming--POP (Post Office Protocol)
          • list servers
        • FTP (File Transfer Protocol)
        • Telnet
        • WWW (World-Wide Web)
          • Vannevar Bush, Memex
          • Ted Nelson, Xanadu Project, coins the term "hyperText"
          • Tim Berners-Lee, HTTP (HyperText Transfer Protocol), HTML (HyperText Markup Language). Initially at CERN, now head of W3 Consortium.
          • NCSA, Mosaic. Marc Andreessen leaves to found Netscape with Jim Clark.
        • NNTP (Net News Transfer Protocol)--Newsgroups
        • Finger
        • Gopher
        • WAIS (Wide-Area Information Server)
        • Directory services
          • X.500 (individual users)
          • Archie (FTP-accessible files)
          • Veronica (Gopher-accessible files)
      • Security
        • Authentication
        • Encryption