Introduction to Computer Networks — Question 30

(i) Modem — Modem converts digital signals to audio frequency tones which are in the frequency range that the telephone lines can transmit and it can also convert transmitted tones back to digital information.

(ii) Switch — A switch is responsible for filtering i.e., transforming data in a specific way and for forwarding packets between LAN segments. To insulate the transmission from the other ports, the switch establishes a temporary connection between source and destination and then terminates the connection once the conversation is done.