Archean Technologies recently released an IP matrix and IP amplifier: the ATVOIP422 and ATBV160DVOIP.
The products do not require a dedicated network as well as providing low latency and an adjustable sampling rate. They work with our without a system server and include an impedance line monitoring card.
The company claims the solution is simple and cost-effective and is targeting all IP markets, particularly transport, shopping centres, hospitals and universities.