Server Vs. Vonage Device

After hours of attempting to host a private server online without any success, we've learned that the only problem was a Vonage VoiP device that was acting as a router: The solution was simply to reconfigure the Vonage device so it is connected from the router rather than directly from the modem and to the router, then we setup quality of service (QoS) on the router for the Vonage device and Voila! Everything else just falls into place... This solution also applies for Remote Desktop Connections

WHY BUILT A DEVICE TO DO A JOB IT WAS NOT INTENDED TO DO?