VoIP (or Voice over Internet Protocol) is a general term used to describe various transmission technologies, communication protocols, and methodologies that are used to provide voice communication over an internet connection rather than a POTS (Plain Old Telephone Service) copper line. DKS 1830 series PC Programmable (1833, 1834, 1835, 1837) and Access Plus series (1802AP, 1808AP, 1810AP, 1812AP) Telephone Entry Systems can be fitted with a TCP/IP adapter and a VoIP adapter to provide the internet connection for data transfer from the entry system to/from the programming PC and voice communication. The 2334 combines a VoIP and TCP/IP adapter to simplify installation and setup.