week 1 : Introduction to Data Communication

What is Data Communication?
The word Data Communication is come from Telecommunication and Data.
Meaning of Telecommunication is "The Communication at a distance", and the meaning of Data is "Information presented in whatever form is agreed upon by the parties creating and using the data".So, Data communication are the exchange of data between two devices via some form of transmission medium (like wire cable, fiber optics)

In Data Communication, We have mainly have 5 network type (base on scale) which is
1. Local Area network (LAN)
- LANs is a group of PCs that share a circuit. This type of network can be seen in computer room or building.
2. Backbone Networks
- A high speed backbone linking the LANS at various locations.
3. Metropolitan Area Network (MAN)
- This network type is optimized for a larger geographical area than a LAN, ranging from several blocks of buildings to entire cities.
4. Connects LANs and BNs at different locations
5. Wide Area Networks (WANs)
- Same as MAN but more wider scale.

Data Flow
Data flow is a group of traffic, identified by a combination of source address/mask, destination address/mask, IP next protocol field, and source and destination ports, where the protocol and port fields can have the values of any.

General type of Data flow
- Simplex (Data can be sent one way only, from Server to client.)
- Half-Duplex (Data can be sent from sender and receiver but can send only one at the time.)
- Full-Duplex (Data can be sent and received at the same time.)