Sunday, 29 April 2012

Week 5 - Cabling

Ok its already our fifth lecture. There are so many things that I learnt before. Today we learnt new thing that is cabling.


What is cabling??

Cable is the device that information usually moves from one network to the other network.

There are 4 types of cable that we had learnt:

UTP cable (unshielded twisted pair)

consists of two unshielded wires twisted around each other
low cost
used extensively for local-area networks (LANs) and telephone connections

STP cable (shielded twisted pair)

each of the two copper wires that are twisted together are coated with an insulating coating that functions as a ground for the wires
extra covering in shielded twisted pair wiring protects the transmission line from electromagnetic interference
often is used in Ethernet networks

Co – axial cable

type of wire that consists of a center wire surrounded by insulation and then a grounded shield of braided wire
shield minimizes electrical and radio frequency interference.
used by the cable television industry and is also widely used for computer networks, such as Ethernet
much less susceptible to interference and can carry much more data

Fibre optic cable

consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves
have a much greater bandwidth than metal cables
less susceptible than metal cables to interference
much thinner and lighter than metal wires

ok thats all for this week..
see you in next post..

Week 4 - Topology, Protocol & Architecture

Today is our 4th lesson. In this class we started learning about topology and others element of network.

What is topology??

Network topology is the study of arrangement of the nodes of networks.

Physical topology is the way that the devices on a network are arranged and how they communicate with each other.

Logical topology is the way that the data passes through the network from one device to the next devices.


Linear bus topology 

All devices are connected to a central cable, called the bus
relatively inexpensive and easy to install for small networks
System that uses linear bus topology is Ethernet.

Ring topology

All devices are connected to one another in the shape of a closed loop.
Relatively expensive and difficult to install.
Offer high bandwidth and can span large distances.

Star topology

All devices are connected to a central hub.
easy to install and manage
Disadvantage - bottlenecks can occur because all data must pass through the hub.

Tree topology

combines characteristics of linear bus and star topologies
consists of groups of star-configured workstations connected to a linear bus backbone cable


Protocol is set of rules that govern communication between the computers in network.

Example of protocols:


use the linear bus topology
supports data transfer rates of 10 Mbps
uses the CSMA/CD access method to handle simultaneous demands

Token ring

use token passing as access method

Local talk

develop by Macintosh computers
popular because they are easy and inexpensive to install and maintain


is Fiber Distributed Data Interface
•      support data rates of up to 100 Mbps
used as backbones for wide-area networks.


Have two categories:

Peer to peer architecture

each workstation has equivalent capabilities and responsibilities
disadvantage - usually do not offer the same performance under heavy loads.

Client server architecture

also known as two-tier architectures
Servers are powerful computers or processes dedicated to managing file servers, print servers, or
        network server


Asynchronous Transfer Mode
network technology based on transferring data in cells or packets of a fixed size
small, constant cell size allows ATM equipment to transmit data over the same network
assure that no single type of data hogs the line