In the world of the Internet of Things, it’s no surprise you can view your security cameras even when you’re not at home. Your CCTV network, though closed to the rest of the world, has to be accessible to you from wherever you are, so your security installer has to set up your network to allow that. This is done by configuring your Local Area Network to accept Internet traffic through certain authorized ports, and this allows for remote viewing. But how exactly do you open a port without letting everyone into your surveillance system?
An Introduction to IP Addresses
Every device using Internet Protocol has an IP address that routs requests and replies to the right place. IP addresses are similar to a telephone number – a series of digits used to identify which device a transmission is sent to. The most common protocol in use today is IPv4, but a longer version called IPv6 is also available. There are two basic kinds of IP addresses, dependent on what kind of network they’re used on. Small, local networks like your home or business connection based around your router and modem use private IP addresses. The other side of every router has a public IP address, which can be used by others to access a server or website accessible to the public.
Private IP Addresses
Every device on your local network has a unique IP address. These are generally pulled from a pool of numbers and assigned randomly as devices come on and off the network. Your smartphone, for example, might not have the same address as it did when you left the house. Addresses on your Local Area Network are generally in a designated range – a common range is 192.168.0.0 to 192.168.255.255. Your router often appropriates the address 192.168.1.1 for itself, and all your other devices follow. You can assign a device a permanent IP address, which lets you reach that device at any point as long as you remember what that address is.
Public IP Addresses
From outside your network, your router is visible through a different IP address that is assigned by your Internet provider. Small businesses and residential networks have dynamic addresses that change periodically based on power fluctuations and outages, so your public IP address might not be the same as it was yesterday. This is important to note for setting up remote viewing.
This presents a problem if you want to connect to your home network remotely. You can’t check to see your network’s public address unless you’re on it, so you need a way to reference it without having to check it constantly. That reference will effectively be a website name associated with your network, called a dynamic Domain Name System, or DDNS. Once you set up your network for DDNS, the application will push your new public IP address to your service when it changes.
In the security industry, this is important for remote viewing of your security system. After setting up port forwarding and DDNS, you’ll be able to enter a domain name into an Internet browser and log into your NVR or Video Management System just like you would when you’re on the network.
Simply entering your DDNS into a browser won’t necessarily get you to your NVR – you’ll have to tell your router to let certain traffic through the firewall and which device to go to. This is done through port forwarding, which assigns specific ports to specific devices on your network. Any traffic requesting those ports will be let through the firewall and into the device, allowing you to interface with a computer or server on your local network remotely. When you set up DDNS, you’ll generally be routed to port 80 by default, but traffic using the standard http:// Internet protocol will be sent through port 8000.
Once the settings have been configured on your network’s end, your device needs to be configured to allow for remote viewing. If you’re using a web browser, this means simply entering the DDNS name in the address bar. For an app, you’ll have to enter the credentials and port for your NVR before you’re able to view your feeds.