dvrsecuritylab

you said that "it went down" so does it mean that it was working in the beginning? if it was working before, then it shouldn't be the problem with port forwarding, unless your router settings were somehow reset.

I thought this is about a stand alone DVR. This is an interesting question, I should try it on my dvr here.

We sell this DVR at our store, unfortunately I don't think such option is available.

I agree with rory, You probably just have to replace it.

I would recommend cameras that have 420 or more TV Lines (best 480 or more, but that might go over your budget). Since you are using it outdoor make sure the ones you get are weatherproofed (or place the cameras in outdoor housings). Although you want to use them at night, but since the locations already have lights, I would suggest something WITHOUT IR leds (instead get cameras with better sensors). To be discreet, you can go with a bullet camera. if you can accept bigger cameras, then a box type camera placed in housings might be a better choice. Box type cameras tend to have better specs at the same price range compare to bullet cameras.