plex media sever public ports open?

I don't want a list of blocked ports or directions for port forwarding. I had no problems with xfinity but cox is blocking every port number I have manually put in for my plex server to be accessible to me via the internet when I am not home. Can cox look up or even dedicate a port for such things as peoples private media servers. this should not be an issue for so many people out there. just a port number that is confirmed to work for plex,on cox internet thats all I ask.......