call forwarding vs telephony

call forwarding and telephony both are nouns.

Word	Noun	Adjective	Verb	Adverb
call forwarding	Yes	No	No	No
telephony	Yes	No	No	No

As nouns, telephony is a hypernym of call forwarding; that is, telephony is a word with a broader meaning than call forwarding:

call forwarding: lets you transfer your incoming calls to any telephone that you can dial direct
telephony: transmitting speech at a distance

Other hypernyms of call forwarding include telephone.

call forwarding (noun)	telephony (noun)
lets you transfer your incoming calls to any telephone that you can dial direct	transmitting speech at a distance