Hey, I had the exact same problem, here is what I did to fix it.
first get your router IP like on mine its 192.168.1.1 then I entered default manufacturer password. then I clicked on "application & gaming" from there I clicked on "Port Range Forwarding" under application, put any name start 8080 to 8090 end select TCP put in the ip of your dvr select enabled then do that on the next line but start 3001 to 3005 end everything else the same. , then still under applications & gaming select "UPnP forwarding" find application HTTP ext port is 80 TCP for INT Port put 80 put in the dvr's IP address select enabled. thats exactly what I did and now it works.