KEY DATA COMMUNICATION TERMINOLOGY

• Link: connects adjacent nodes Wires, Cables, Any thing that physically connects two nodes
  

• Path: end-to-end route within a network

• Circuit: the conduit over which data travels

• Packetzing: dividing messages into fixed-length packets prior to transmission over a network’s communication media
  

• Routing: determining a message’s path from sending to receiving nodes

• The transmission medium may itself be a network, so route needs to be specified

Network
“A NETWORK is a set of devices (Nodes) connected by Communication Links”

• Node: Can be a Computer, Printer or any other device capable of sending or receiving
  

• The links connecting Nodes are called COMMUNICATION CHANNELS Networks- Why we need them?

Networks- Why we need them?
It is often impractical for devices to be directly connected for two major reasons:

• The devices are very far apart. They are expensive to connect just two devices with one in Lahore and other in Islamabad
  

• Large set of devices would need impractical number of connections e .g. Telephone Lines in the world and all the computers owned by a single organization

Solution to the Problem=Networks

• Solution is to connect all devices to a central system known as a NETWORK in which all terminals or computers share the links.
  

• Two Main Classifications of the Networks

• LANS
• WANS

DISTRIBUTED PROCESSING

• Instead of a single large machine being responsible for all aspects of a process ,each separate computer handles a subset of the task
  

• Example – Project Given as a part of the Course
• Example – Office Work

Advantages of Distributed Processing

• Security

A system designer can limit the kind of interaction that a given user can have with
the entire system.

• For example : Bank’s ATM

• Distributed Data bases

No one system need to provide storage capacity for the entire database

• For example WWW gives user access to pages stored anywhere on Internet

• Faster Problem Solving

Multiple computers working on a problem can solve a problem faster than a
computer working alone

• Security through Redundancy

Multiple computers running the same program provide security through redundancy
If one computer's hardware breaks down others cover up

• Collaborative Processing

Both multiple computers and multiple users can interact for a task