Chapter 1: Networks

1
Chapter 1 Networks

• Sections 1.1 1.4

2
Networks

• Network is a combination of software and
  hardware that allows computers to exchange and
  share software and devices, such as printers.
• Allows users to reliably share and exchange data
• Can reduce costs by sharing devices such as
  printers
• Can be set up to allow users access to only
  specific files
• Simplifies the process of creating backup copies
  of files
• Allows users to communicate with e-mail
• Networks are classified by their size,
  architecture, and topology.
• LAN (Local-Area Network) is a network used to
  connect devices within a small area such as a
  building or a campus
• Requires a network interface card (NIC) to
  connect to an Ethernet cable
• WAN (Wide-Area Network) is used to connect
  devices over a large geographical distances.

3
Software, Networks, Topology

• Operating System is software that allows the
  user to communicate with the computer.
• Examples Windows, Mac OSX, Lennox
• Network architecture is the structure of a
  network, which determines how network resources
  are handled
• Two common models are client/server and
  peer-to-peer.
• Client/server network consists of several
  client computers hooked into one server.
• Peer-to-peer network does not have a server
• Network topology is the arrangement of the
  network and how the network hardware communicate
• Physical topology refers to the arrangement of
  the nodes on a network
• Logical topology refers to the way that data is
  passed between the nodes on a network.

4
Network topology

• Bus topology is a physical LAN topology that
  uses a single central cable, called the bus or
  backbone to attach each node directly.
• Star topology each node is attached to a hub,
  which is a device that joins communication lines
  at a central location on the network. (What the
  school uses)
• Ring topology each node is connected to form a
  closed loop.
• Transmission Media is what joins the nodes on a
  network to enable communication.
• Bandwidth is the amount of data and the speed
  at which the data can travel over the
  transmission media.
• Twisted-pair wiring telephone cord
• Coaxial cable (copper wire center) old cable TV
  cord
• Fiber optic cable (glass/plastic wire center)
  new cable TV cord
• Wireless networks radio waves transmit the
  data. WI-FI

5
Network Protocols

• Specific standards or protocols are used for
  Local Area Networks.
• The main protocol used today is Ethernet
• Ethernet was developed in 1976 by Bob Metcalfe
  who worked for Xerox at the time, Digital
  Equipment corporation and Intel corporation
• Ethernet protocol can use phone cord, coaxial
  cable, or fiber optic cable.
• Speeds varying from 10 mbps, 100 mbps, and new
  gigabit Ethernet which operates at 1 gbps.