First of all, we need to differentiate between LAN and WAN . I try to explain in the simplest way possible:
-LAN: (local area network): computers connected together through a router, sucha home network (3 pcs, 1 ip camera, connected torouter).
-Wan: (large network), would all LANs connectedeachvia the Internet. (House 1 with 3 pcs, connected with House 2 5 pcs and camera, etc …).
To identify our network LAN internet, our service provider (Movistar, ONO, etc), we assigned an IP address public which is like our identity card to identify internet. Pictured our public IP would 188.8.131.52
Then within our local network or LAN each device connected via an internal IP router will have to be identified within this network. These usually start IP 192.168.1 . X , being X a version for each connected device.
Typically, the router is configured to allocate IPS automatically by DHCP , and whenever restart can change their IP. You can be assigned manually to better identify each device, which is known as static IPs.
To avoid this problem will disable DHCP and assign one IP fixed to the device you want. In our case in camera, video recorder , etc. (Example, I want my camera is always ip 192.168.1.25 )
Like watching my camera out of my network from the Internet (from anywhere)
In this case, talking about viewing our surveillance cameras or IP cameras from outside of our network, we can do indicating the external IP 184.108.40.206 and our camera IP 192.168.1.25 .
However in practice this computer complicate a little and to refer to a local IP or LAN , we have to make the router to assign a port to each IP local network .
A port is the way for the router to classify the data that come and to send them to one or another local IP. There is a router port 65535 of them are some that we should not use reserved.
Normalente, the first local IP networks, is often the asginada for the router (see photo), ie, it would be 192.168.1.1 , and to access the router just put this address in a browser (Firefox, Chrome, Internet Explorer) takes us to our router.
Ask us to enter and we have to know the username and password of your router (may appear below the router, our internet provider it should give us, and usually normally admin-> admin, 1234-> 1234, Vodafone> vodafone etc …)
Once inside the router to assign a port to an IP let the NAT tab will make the allocation.
Finally for viewing our camera from anywhere via the Internet, a browser add our public IP: port that we have opened. (Example)