Otto

The reason why this does not work is the because the ISP does not allow loop back from inside its own network. In my experience comcast does not allow loop back. Most DSL providers do allow it. If you are on a cell phone testing your external connection. Just turn off your wifi and use your cell phone data service with the mobile app to test. Also a big mistake people forget is to set their gateway to the right ip. If you do not set that correctly you will never get the dvr out on the internet. Also setting an incorrect dns will stop your dvr from connecting to ddns and email notification as well.

Make sure that the twists of the pairs begin inside the connector as close to the split as possible. I see a lot of spaghetti strings going into connectors lately.

You may have crossed your video pairs together. Or somewhere down the line of the cable is damaged and crossing into each other. try moving the positions on the dvr if it shows up on ch 8 put it on ch 1.

You don't need a license to install a DIY or even pro system in your own home if you are asking. You most likely will need a permit depending on the city that you live in. Like others have said the license to install commercially is so that you do not mess up someones house. Even though it is DIY equipment, what happens if the power part of the cable shears off and sparks on something that catches fire in the ceiling. What if you improperly run the cable over a hot or high powered light fixture that causes interference. There are too many things like this and many more that the average DIY installer does not know about. That is why there is a "code", a set of rules that you should follow when running wires. Being licensed is about protecting the consumer from people that do not have the experience to do things the right way.