Welcome Barbara: Here's something to consider. NuVox has started using Sonus for some of their long distance. https://www.sonusnet.com/contents/solutions/apps/apps_longdistance.cfm

They package LD a lot like cell companies lately. NuVox is also offering a VOiP service that works like PRI and connects like PRI. Some of thier techs have lost their jobs over protesting the problems with supporting both Sonus and VOXIP.