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.

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.



TYPES OF TOPOLOGY

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

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

Example of protocols:

Ethernet

• 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
• slow
• popular because they are easy and inexpensive to install and maintain

FDDI


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



ARCHITECTURE

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

ATM 

• 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