Telephony n. : The art or process of reproducing sounds at a distance, as with the telephone.

Example:
What does the acronym ACD stand for in IP Telephony and how does it work?

Taxonomy
Telephony, telephones, free encyclopedia, exchanges, equipment, cable, wire center, the network, CTI, digital telephony, telephone calls, search, Unsourced, free dictionary, teh, LEH, fuh, nee.

Defination from the web:
telephony in Wiktionary, the free dictionary. In telecommunication, telephony (pronounced /təˈlɛfəni/ or teh-LEH-fuh-nee) ... A new generation of applications (middleware) is being developed as a result of standardization and availability of low cost computer telephony links. ...