Well, pretty simple straight forward question with a lot jibber jabber answers.
I was brought here via google search for the same question, whats the pinout for the rj45 (ethernet) connector to add new cameras. Luckily I didnt stop last here or I would have never got it done.
Just about any camera will do. make sure it is 12Vdc.
You will need to buy a balun. This changes the BNC 75 ohm signal and matches it for the twisted pair in the cat 5 you will be running (300 ohm)
The samsung unit has the other balun built in so you only need one balun on the camera side.
you can buy video baluns at cctv warehouses or online, they cost about 10 bucks a pair.
Using a standard RJ45 female connector (most probably the punchdown kind found in a wall jack. purchase this at radio shack or home depot.
1. Punch down a one foot section of Cat5 or Cat6 cable into the female rj45 connector. Make sure to follow the color code for the "B" colors. You can use any standard, but the color code pin-out below will be wrong in any other example.
2. Take the Brown and Brown-Stripe wire and wire them into the + and - of the balun.
3. Take the Orange-Stripe and Blue wire and plug them into the positive 12V camera connection
4. Take the Orange, Blue-Stripe, and Green Stripe and plug them into the negative 12V to the camera.
5. Allow the Green to hang free.
Use a short patch cable and plug the camera into the DVR and see if you have picture (Use a standard patch cable, never a crossover cable)
If no video swap the Brown and Brown-stripe around on the video balun and try again.
It really is quite simple. Hope this write up helps someone.