The Evolution of VoIP

I read a blog ( this morning by a noted blogger that discusses VoIP’s evolution. It is an insightful article and highlights that there are two components to the purchasing decision, the phone system and the service. He also acknowledges that for companies with sunk costs in legacy phone systems that are still going strong the ability to IP enable those legacy phones is readily available using “an Analog Telephone Adapter (ATA) or comparable peripheral for each endpoint”. I guess it is time to come up with terminology for “comparable peripheral” so readers attempting to learn about VoIP or update their knowledge base know clearly that there are comparable devices that SIP enable digital and P-Phone handsets as well as analog phones which are clearly handled by ATAs. Any ideas as to the terminology to use. We created the abbreviation TVA to stand for Telephone VoIP Adapter however as that is so closely identified with Citel, I guess that is the reason bloggers are concerned about using that term. What term do you or would you use?