Friends and I can not connect to my server.

[Rinzler]

Been using vent for a long time now to play games with close friends and family. Then one day we get online and nobody I play with can connect to my server that I am renting. Cant even connect to other severs that my friends use as well. Would like to know how to fix this problem. I also did a server request and it said my server not responding, so perhaps it on Ventrillo's end. Any help would be great as its really annoying to not be able to chat with friends in game. Also like to note that I have reset router and modem multiple times as well and my PC. Also uninstalled Vent twice, and nothing. Every time I hit connect it just says connecting to server and never connects. So yeah that's about where I am now.