You're completely ignoring the existence of the NAT. I know you don't know what that is, but it is true nonetheless.
Don't change the port numbers in the camera's web interface.
Here's an outline of what you should do:
1. Turn off UPnP in the routers at locations A and B. This will prevent things being forwarded without your knowledge.
2. Set up port forwarding rules
in the router at location B. 4 total ports need forwarded. As an example, assuming the public IP address at location A is
8.8.8.8, and camera LAN addresses are
192.168.0.100 and
192.168.0.101, your rules would look something like this:
| Protocol | Source Address | External Port | Internal Port | Internal Address | Description |
|---|
| TCP | 8.8.8.8 | 21101 | 80 | 192.168.0.100 | Cam 1 HTTP |
| TCP | 8.8.8.8 | 21102 | 554 | 192.168.0.100 | Cam 1 RTSP |
| TCP | 8.8.8.8 |
21103 | 80 | 192.168.0.101 |
Cam 2 HTTP |
| TCP | 8.8.8.8 | 21104 | 554 | 192.168.0.101 | Cam 2 RTSP |
I know not all routers have a clean and simple interface for port forwarding like this. But hopefully you can translate to whatever your router has.
Your router might not allow you to specify the source address, in which case you can still do this but you'll be opening up the cameras to the entire internet which will probably get them hacked. I would not recommend port forwarding to a camera if you can't restrict the source address.
For the external ports you can use just about any number you want between 1 and 65535. The ones in my example would be fine, I just pulled them out of my butt. By using high numbered ports like this you will drastically reduce the number of intrusion attempts coming in from the internet and reaching your cameras.
You can omit the HTTP ports if you don't need PTZ control. Or perhaps 2-way audio. Not sure what port that normally uses.
3. In
Blue Iris you enter the public IP address of location B into the host name area, and 21101 for the HTTP port, 21102 for the RTSP port. That would be for the first camera.
