Welcome to Cisco Support Community. We would love to have your feedback.
For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.
Let me know the router model and your exact requirement. Also post the current router configuration by removing all sensitive information.
What is the router you have to work with? Have you managed to log in to the port forwarding configuration page at all?
If you have what address are you forwarding the ports to as this should be the I.P address of the DVR.
video on how to open the router port for DVR 37777, 37778 :-