I have been using Digital Watchdog cameras and DVRs, so I'll use them as an example. When the DVR and viewing software are set up, it's necessary to name the DVR, then enter that name in the DDNS area of the network setup. The first thing needed is to get an IP address from the router, but in order to view through the DVR, it's necessary to open a port in the router- think of it as a secret handshake. It's also necessary to find the PUBLIC IP address, which is the one seen from the outside world. That's where whatsmyip.com is good for. Each manufacturer's setup is different, but they have many similarities. Once the software on the computer is set up, it may have two different ways to view the cameras- one is on the local network (where the 192.xxx.xxx.xxx address resides) and the other, accessed using a phone or a computer in a different location. That one is actually going to the DDNS server and finding the DVR with the unique name followed by dvrname.ddns.net, dvrname.dynddns.net, or whatever. IC Realtime has people on hand who will assist in setting up the rest of the configuration, as do the other manufacturers.

For info on port forwarding, go to www.portforward.com and look for the router, then the device that needs to be accessed. It will step you through the process.