Port forwarding help!

I have a situation with 4 outside security cameras connected to a digital recorder which in turn is wired to my modem.  I also have a phone app that allows me to access my live cameras when I am not home.  About 2 weeks ago, a tech checked and seen that the ports were closed. Now that they are open, I'm still unable to remotely connect to my home cameras remotely. A Comcast tech was at the house 6 months ago and was able to make the remote connection, why can't it work now? I called Comcast and spend 5 hours on the phone in 2 days with no results. I'd love to know who that "magical" Comcast tech was so I can find out how to fix this!