1. The external IP address of your camera.
2. The port that your camera is on (http and maybe also rtsp).
3. The make/model of your camera … or the “Snapshot URL” of your camera.
To get around this, one needs to create a rule on your router that will direct someone from a specific port on your router to the IP of your camera. This is called Port Forwarding, or sometimes NAT or Network Address Traversal. Some routers have other names too, it can be confusing. There is a website www.portforward.com that goes into this in more detail.
Your task is to create port forwarding rule for both the HTTP port (usually 80) and the RTSP port (usually 554) on your camera to the outside world.
For Evercam’s purposes, these are the only 2 ports you need. In fact, just the HTTP port is usually enough.
Where it get’s tricky is when you need to setup “Port Forwarding” (see above). This effectively maps your camera’s local port (80?) to a different port on your router (usually not port 80, but some number between 10 and 60000). You will only know this number if you have the details of the port forwarding configuration.
It can be tricky to know if your ports have been correctly forwarded from the perspective of someone who is not on your network. A tool for doing this is: http://www.canyouseeme.org/