Zusammenfassung der Ressource
Networks
- Overview
- Network card
interface (NIC)
is inside every
computer
- networks let
computers
share resources
- Some connected
by wires or by
telephone lines
- file server = shares programs
and data files on backing storage
- Print server = share a printer
- database server = stores larger
database
- mail server = manages email
traffic
- Advantages
- Hardwarecan be shared (less cost)
- Software can be shared
- Data cab be shared
- Computers can communicate
- Controlled by network manager
- Easier to make scheduled back ups
- Disadvantages
- Cables cost
- Networks can be attacked by hackers
- Files can be compramised
- Network crash caused havoc hard/soft ware and data cannot be shared
- Types of network
- Peer-to-peer = all computer are
equal
- Client-server = one
high powered
computer is the server
- LAN = Local area network (in one area)
- WAN = Wide area network (international)
- Topologies
- Bus = next to each other,
one computer crash
doesn't matter, slow
- Star = connected to central
HUB, 1 crash doesn't matter
but is HUB crashes all are down
- Ring = data is sent in a loop, one
crash stops flow so all crash
- intranet is the internet but in
one organisation (restricted)
- extranet is part of the
intranet that can be
accessed by
authorised members
- Network security
- Passwords
- Access rights
to certain
members
- Encryption
- Back ups
- Firewall
- Virus protection
- Data transmission
- Cable = metal copper or fibre optic
- Wireless (microwave, infrared, radio)
- Satellite
- Bluetooth = connects to PDAs
eliminated the need for cables
- Packet switching = packs of
data stored in binary code
- Components
- Switch = filters data
packets and forwards
them between
network segements
- Gateway = allows a LAN
to connect to a WAN
- Router = forwards data packets
along a network. normally at
gateways and configure with other
routers to find the best route
- Bridge = connects LAN to another LAN