Yes. NHT is well versed in digital systems. We possess a working knowledge of Samsung, NEC, and Nortel systems.
All of the systems we sell and support can use either traditional phone lines or call over the Internet--depending on whether you are in a location that delivers reliable Internet.
We prefer to demonstrate how SIP (otherwise knows as VOIP) based systems offer more options, flexibility, cost less and are more economical to maintain. We only use VOIP in our offices because it didn't make sense to spend a premium on old (1990's) technology that offered fewer options than the newer (circa 2005) technology. And our call quality is great.
Here is a sample of what NHT offers.