Data Communication Prepared By: MIHE IT Department
DEFINITION of DATA COMMUNICATION“Data Communication is the exchange of Information from one entity to the other using a Transmission Medium”
LOCAL and REMOTE Communication LOCAL – Communicating devices are present in the same building or a similarly restricted geographical area. – When the source and destination are in the same network
Data Communication Definition (Modified)“Data Communication is the exchange of data (in the form of 0’s and 1’s) between two devices (computers) via some form of the transmission medium.”
LOCAL and REMOTE Communication REMOTE – Communicating devices are present farther apart. – When the source and destination are in the different network.
Data Communication System For Data Communication to occur, communicating devices must be a part of a system made up of some specific kind of hardware and software. This system is known as “DATA COMMUNICATION SYSTEM”
Effectiveness of Data Comm. System Delivery (the data you send and it is received to the destination) Accuracy (what you send the same is received and there is no error) Timeliness (the data reach to the destination in good time).
Components of a Simple Data Communication System
Components of a Data Communication System∗ A Data communication system is made up of 5 components: ∗ Message ∗ Sender ∗ Receiver ∗ Medium ∗ Protocol
Components of a DataCommunication System Message: It is the data which the source send to destination∗ Sender: a device which sends the data.∗ Receiver: a device which receive the data.∗ Medium: the path through which the data is traveling from sender to receiver.∗ Protocol: Set of rules that govern communication or set of rules that makes the communication both possible and efficient.
Transmission media Guided media unguided media Twisted pair cable optical fiber water, air, vacuum coaxial cableShielded twisted pair Thick net Single modeUnshielded twisted pair Thin net Multimode
Transmission Media Medium Speed Cost Twisted Wire 100bps-1000Mbps Low Coaxial Cable 56Kbps-200Mbps LowFiber Optic Cable 500Kbps-10Gbps High
Wire Based MediaTwisted-pair cable ∗ Most common LAN cable Called Cat5 or 100BaseT ∗ Four pairs of copper cable twisted ∗ May be shielded from interference (polyester/aluminum) ∗ Speeds range from 1 Mbps to 1000 Mbps ∗ Twisted to remove the cross talk ∗ UTP and STP are types of twisted pair
Wire Based MediaCoaxial cable ∗ Also called coax ∗ Similar to cable TV wire ∗ One wire runs through cable ∗ Shielded from interference ∗ Speeds up to 200 Mbps ∗ Nearly obsolete ∗ Expensive than Twisted pair
Wire Based MediaFiber-optic cable ∗ Data is transmitted with light pulses (signals) ∗ Glass strand instead of cable ∗ Protected to interference ∗ Very secure ∗ Hard to work with ∗ Speeds up to 10 Gbps
Source A device which generate data Transmitter Is a device which takes data from source and convert it into a form that is transmutable over transmission media Transmission system Is the path available between source and destination and through which the data can travel. Receiver Is a device that takes data from transmission system and convert it into a form that is understandable by computer. Destination It is the final point of communication.
Key Data Communication Terminology∗ Network: interconnected group of computers and communication devices. ∗ Can share the resources ∗ Can share the data∗ Node: a network-attached device that can send and receive the data. E.g. Computer, router, Switch.
Key Data Communication Terminology∗ Link: links are the path that connects adjacent nodes∗ Path: end-to-end route within a network∗ Circuit: the conduct over which data travels. Circuit is the path for current flow. Circuit can be open or close. Open circuit means that there is a break in the wire and current can not pass. A close circuit means that circuit is complete and current can pass
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∗ Router: router is the device that perform the function of routing and switching