n The main components of data communication are sender, receiver, medium and message
n The data to be sent is converted into signals and then transmitted over the network
n Signaling techniques are of two types - broadband and baseband
n Baseband signals transmit data at a single frequency
n Broadband technique can transmit data using more than one frequency
n Network Interface Cards are devices that are used to get connected to different computers on a network
n Some examples of NIC are Ethernet Card and Token Ring Card
n Ethernet cards support transfer rate of 10 or 100 or 1000 Mbps
n MAC address is a hardware address that is embedded onto the NIC
n Lower layers of OSI model identify nodes on the network by their MAC address
n A connection established between two nodes by directly connecting a cable is known as direct cable connection.
n Signals lying on the cable are absorbed by the terminators at the end of the cable to avoid collision.
n Cross over cables can be used for temporary connection between two devices when switch or hub is not present.
n Volt-ohm meters is a cable-testing tool which is used to troubleshoot the network cabling.
n Volt-ohm meter is used to measures voltage and resistance and to check the continuity of a cable.
n Tone generator and probe is another troubleshooting tool which has the ability to identify wires, finding open circuits and short circuits, diagnosing crosstalk and other telecom tasks