There are call centers which advertise to medical professionals which are not call centers at all. A professional medical call center is a complex business in its own right, and operates a lot of very expensive technology. They have redundant communications systems at their facilities that allow them to stay live in the event of disasters. In the event of a disaster in your area, they can use a multitude of different types of communication to keep your business operating and your patients cared for. If it's time for your business to take this next step, be sure that you hire a professional organization.