1. Chapter 3: Introduction to Data Communications and Networking
information (knowledge or intelligence) that is stored in digital form
Data Communication Circuit
 equipment to transfer digital information from one place to another
Data Communication Network
set of devices interconnected by media link

2. Data Communication Network Architecture
current
legacy
legendary
Data
frames, blocks or packets
Data Communication Network
broadcast ( messages for all subscribers on the network )
point-to-point
multicast ( messages for a specific group of subscribers )
Protocol
procedures that the systems involved in the communications process will use

3. Data Communications Circuits
Utilize electronic communications equipment and facilities to interconnect digital computer equipment. There are
Source
Transmitter ( convert data to different and appropriate form )
Transmission medium
Receiver (convert the encoded signals to the original form )
Destination
Serial and Parallel Data Transmission
parallel by bit ( for short distance data line )
serial by bit (for long distance)

4. Data Communication Circuit Arrangements
Two-point
involve only two locations or stations
Multi-point
involve a host (such as mainframe computer) to many PCs
Transmission Modes
Simplex
data can be sent only one direction
Half duplex
data can be sent in both direction but not the same time
Full duplex
Full/full duplex
data transmission can be sent in both direction at the same time but not between the same stations

5. Networking Applications
Standard office applications
, file transfers and printing
High-end office applications
Video imaging, CAD, software development
Manufacturing automation
Process and numerical control
Mainframe connectivity
PC, workstations, terminal support
Multimedia application
Live interactive video

6. Network Components, Functions, and Features
-Servers (computers that hold shared files, programs and the network operating systems)
-Clients
-Transmission media
-Shared data
-Shared printers and other peripherals
-Network interface card
-Local operating system
-Network operating system

7. Network Classifications

8. LAN MAN WAN GAN 10 to 40 computers
bit rates in the range of 10Mbps to 100Mbps
MAN
Similar to LAN but include larger area
Operate at speeds of 1.5 Mbps to 10 Mbps
Generally use one or two cables
Could be a single network such as a cable television network
Large companies often use their MAN to connect their LAN
WAN
GAN
the internet is a good example of GAN