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

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

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)

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

Networking Applications Standard office applications E-mail, 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

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

Network Classifications

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