15-09-2016, 03:20 PM
1454663444-5IntrotoNetworking.ppt (Size: 606 KB / Downloads: 7)
A network consists of 2 or more computers connected together, and they can communicate and share resources (e.g. information)
How many kinds of Networks?
Depending on one’s perspective, we can classify networks in different ways
Based on transmission media: Wired (UTP, coaxial cables, fiber-optic cables) and Wireless
Based on network size: LAN and WAN (and MAN)
Based on management method: Peer-to-peer and Client/Server
Based on topology (connectivity): Bus, Star, Ring …
:
Transmission Media
Two main categories:
Guided ― wires, cables
Unguided ― wireless transmission, e.g. radio, microwave, infrared, sound, sonar
We will concentrate on guided media here:
Twisted-Pair cables:
Unshielded Twisted-Pair (UTP) cables
Shielded Twisted-Pair (STP) cables
Coaxial cables
Fiber-optic cables
Advantages and Disadvantages
Noise resistance ― external light is blocked by outer jacket
Less signal attenuation ― a signal can run for miles without regeneration (currently, the lowest measured loss is about ~4% or 0.16dB per km)
Higher bandwidth ― currently, limits on data rates come from the signal generation/reception technology, not the fiber itself
Cost ― Optical fibers are expensive
Installation/maintenance ― any crack in the core will degrade the signal, and all connections must be perfectly aligned