Networks

  A bus structure that links a set of interconnecting nodes with protocols 
    to create a real or virtual temporary or permanent point to point 
    connection between 2 nodes on the network with the possibility of 
    redundant paths.

    # Reason why you pay by minute for phone.
      Original phone system used switches to connect lines to create a physical
       dedicated connection between caller and called for duration of call 
       irrelevant of how much was actually said. Leased by minute.

Three views
  Originally developed in relation to telephones.
   And expanded by D.A.R.P.A.
 
  Local area network (LAN) - linking systems close together.

    Tends toward one type of technology. 
    * back end of wireless access usually switches to copper Ethernet. 

    Throughput reasonably fast but in a limited range.  
 
    Individual nodes are recognized by their hardware id.

    Relatively small area coverage (room, building, or small complex).

    General connectivity - Broadcast communication.
      Often implemented through simple, economical wiring.
      Or short distance radio - WiFi.
 
  Wide area network (wan)
    Aggregation of many local area networks.

    Highly variable technology.

    Point to Point communication via gateways between special routing nodes.
      Highly variable throughput depending on link's technology.
      But some links offer extremely high throughput.


    But also designed for redundant paths in case routing node unavailable.

    End points given a symbolic address supported by public universal protocol.

  Internet - a heterogeneous network of local networks and routing points.
    Because the "Internet" grew and inter-connected randomly over several
    years, the quality and speed of links in the network can vary greatly.

  Internet2 - a very high speed backbone/node interconnection created by a 
    consortium of universities, research institutes, and computer and 
    communication leaders.

    Conceived/established of in 1996 (EDUCOM/EDUCAUSE). 

    Originally designed for research, now also used for commercial as
      long as user is connected by very high speed/capacity technology.

  Commodity Internet - a term for a network section that can be leased 
    by independent companies/individuals. 

  See 'BITNET' on wikipedia for a mid-1990s alternative.

  World wide web - virtual interface that sits on top of the Internet
    and used URLs, uniform resource locators, and hypertext links to 
    provide user friendly access to resources on the Internet.