Course Instructor : Sehrish Rafiq
Department Of Computer Science
University Of Peshawar
Data Communications & Networking
Data Communications & Networking 3rd Edition by Behrouz
Data & Computer Communications 6th edition by william stallings
What is Data communication?
Importance of Data communication
Fundamental characteristics of a data communication system
Components of a data Communication system
Networks & distributed processing
What is Data Communication?
The word data refers to facts,concepts and instructions presented in
whatever form is agreed upon by the parties creating and using the
In context of computer information systems data are represented by
binary information units(or bits) produced and consumed in the form of
0’s and 1’s.
Data Communication is the exchange of data (in the form of 0’s and 1’s)
between devices via some form of transmission medium(such as a wire
Local and remote data communication
For data communication to occur the communicating devices must be a
part of a communication system made up of a combination of hardware
Why study data communication?
Education & research
Fundamental characteristics of a data
The effectiveness of a data communication system depends on
three fundamental characteristics:
A network is a set of devices(often referred to as nodes)
connected by media links.
A node can be a computer, printer or any other device capable of
sending and/or receiving data generated by other nodes on the
The links connecting the devices are often called communication
In distributed processing a task is divided among multiple
Instead of a single large machine being responsible for all
aspects of a process,each separate computer handles a subset.
Advantages of distributed processing:
Security/Encapsulation e.g. ATM
Distributed databases e.g. World Wide Web
Faster Problem solving e.g. Encryption Codes
Security through redundancy e.g. space programs
Collaborative processing e.g. Games in a multi-user environment