VITEK EH16 CAN'T VIEW EXTERNALLY

Hi. I have a Vitek VT-EH16 DVR that I am trying to remotely view on iPhone 6 with

Vitek apple app. I can get viewing locally on local IP and have opened up all the ports I can think of on Verizon DSL router. I don't want to spend $60.00/yr to get a DYNDNS account unless I am sure it will open up the port and let me view remotely.

Any help will be appreciated.

Thanks