Mam Sobia Lectures Lecturer BS IT in Education University

1. Recap of Lecture 1
Data Communication
Brief History of Communication
Data Communication System

2. Key Data Communication
Terminology
Networks and their need
Distributed Processing
Network Criteria
Network Applications
Today ‘s Topics

3. Key Data Communication
Terminology
Session:
communication dialog between network users
or applications
Network:
interconnected group of computers and
communication devices
Node:
a network-attached device

4. Key Data Communication
Terminology
Link:
connects adjacent nodes
Path:
end-to-end route within a network
Circuit:
the conduit over which data travels

5. Key Data Communication
Terminology
Packetizing:
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

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

7. Networks- And their need:
Point to point communication
not usually practical
Devices are too far apart
Large set of devices would
need impractical number of
connections

8. Solution is to connect all devices
to a central system known as a
NETWORK
Two Main Classes of Networks
Local Area Networks (LANs)
Wide Area Network (WANs)
Networks- And their need:

9. 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”

10. Advantages of Distributed Processing
Security
Distributed Data bases
Faster Problem Solving
Security through Redundancy
Collaborative Processing

11. Network Criteria
Data
Communication
Network Criteria
Performance Reliability Security

12. Network Criteria
Performance
Number of Users
Type of Transmission Medium
Hardware
Software

13. Network Criteria
Reliability
Recovery Time after Failure
Catastrophe
Frequency of failure

14. Network Criteria
Security
Viruses
Unauthorized Access

15. Network Applications
Marketing and Sales
Financial Services
Manufacturing
Electronic Messaging
Teleconferencing
Cable Television

16. Summary
Key Data Communication
Terminology
Networks and Why we need
Them?
Distributed Processing
Network Criteria
Network Applications