Steps
1. Make sure you are using a computer connected to the same router as the DVR, and the router is connect directly to internet.

2. Determine operating system version and type. Most customers have windows and some have Apple.

3. Discover network scheme. On a Windows PC open a command prompt, type ipconfig this command will tell you what the computers IP address is, the routers IP address is labeled the default gateway.

4. Determine if the default IP address of the DVR is not already being used on the local network. You can do this by leaving the DVR disconnected from network and using the ping command. ping 192.168.1.108 if you get 100% packet loss no other device is using the default IP of the DVR. If you do get a response then something else on your network is already using that IP address and you will need to change the IP address in the DVR by logging in going into network settings.

5.Once an IP address is chosen you will need to check the gateway in the network setting of the DVR. The gateway is the router's IP address typically on small networks it will be 192.168.1.1 or 192.168.1.254. ipconfig will give you this address labeled as default gateway.

6. At the DVR change the gateway to the router's IP address.

7. Change the HTTP port at DVR from 80 to 88. The reason being is that some providers block the port and some services your computer or other devices may already be using this port.

8. With IP address's and ports set reconnect Ethernet cable to DVR and router.

9. On your computer if you are running a 64-bit version of windows open Internet Explorer RUN IN ADMIN MODE.

10. Go to internet options, click on security tab, then click custom level. scroll down about a quarter of the way on the slider and look for DOWNLOAD UNSIGNED ACTIVE-X CONTROLS. Set to prompt. Click OK, then APPLY then OK last time.

11. You should be able to reach the DVR from your computer now. Enter full address in address bar of browser. Typically it will look like
http://192.168.1.108:88 Then click on the compatibility view to install the active -x control to view the it will download windows will ask if you want to install it. You do. Refresh the screen and you should be able to login to the DVR through the web-service.

12. Remember the gateway? You now need that address to gain access to the router. Put that address in the address bar. 99% of routers will need a user name and password.

13. Once in the router you are looking for port-forwarding, pin-holes, virtual servers, or NAT. Sometimes these are separate sometimes they are under firewall settings. It depends on the router.

14. Once you find where to enter the ports generally it will ask you to name the device set it tcp/udp or both. Set to both. Then the device will want external and internal port number. Enter in the same port number for all internal and external. IP address is the address of the DVR. Now look for a apply or save button. click it. The two ports to forward are 88 and 37777. Some routers will let you make one rule with multiple ports. Other routers you have to set up a separate rule for each port. Port changes take a few seconds to a minute take affect. Also some routers need to be restarted after settings are changed.

15. Once ports are saved go open another tab on your browser and go to http://canyouseeme.org
on this site you can enter in your port number click on the button check my port. (have to click on it) if the result is success then you have configured your ports correctly.

If you did not have success check your network settings. It is very easy to miss the gateway setting. Also if the router is connected to another network appliance you will need to bridge the two devices.
It is impossible to make a comprehensive port-forwarding walk-through as the manufactures name options a little differently and the interface almost always looks different.