How do IP cameras work?
Most of the cameras in this archive's later years were IP cameras. This page explains what that means without requiring you to be a networking specialist — because you do not have to be one to use them, and Handykam's whole approach to network cameras was to make sure of that.
What is it?
IP is short for Internet Protocol. When video is captured by an IP camera it is sent to the viewing device as a digital signal on a network, rather than as an analogue video and audio signal carried on a voltage down a dedicated cable. The mechanism of capturing the image is much the same — light, lens, sensor — but the big difference is what happens next: the image can be compressed, and it can be viewed on any device on the same network, and beyond it.
Yes, but what is a protocol?
A protocol is simply a set of rules about how data moves across a network and how it is interpreted at the other end. There are thousands of them. IP, defined in RFC 791 back in 1981, is the principal one: it takes data, splits it up, addresses the pieces, and gets them to the right destination. It is that flexibility of communication which makes moving images around so easy.
Why IP cameras?
The first network camera appeared in 1996. Since then the technology has improved year on year while the cost of producing it has fallen, and the reason it took over is packet switching. Instead of holding open a continuous circuit between camera and screen — which is what an analogue video cable effectively does — the data is broken into packets which travel to the destination independently and are reassembled at the other end. No permanently open circuit has to be maintained, and no signal is lost simply because the link went quiet for a moment.
The practical consequences are the ones people notice: higher resolution than an analogue video signal can carry, far more flexible recording, and viewing from anywhere rather than from the television the cable happens to reach.
IP addresses
Like a house address, every device on a network has a unique number — its IP address. On a home network this is usually a set of four numbers such as 192.168.1.64. When you type a memorable web address into a browser, that name is translated into an IP address behind the scenes, because a name is easier to remember than a string of numbers. IP cameras use exactly the same structure to connect and to move data from camera to viewer.
This is the one piece of networking a nest box camera owner sometimes has to touch. If a camera stops appearing in its app, finding its IP address on the router's list of connected devices and opening that address in a browser is almost always the way back in.
Streams, apps and standards
An IP camera does not simply "send video". It publishes one or more streams, usually over RTSP, which any compatible viewer can subscribe to. Better cameras publish several at once — a high-resolution stream for recording and a lower-resolution one for a phone on a slow connection — which is why a good network camera can look sharp on a monitor and still work over a weak mobile signal.
Most decent cameras also implement ONVIF, an open interface standard. ONVIF is the reason a camera is not permanently married to the app it shipped with: an ONVIF camera can be added to a different viewer, or to a network video recorder from another manufacturer. When buying a network camera, ONVIF support is one of the few specification lines genuinely worth insisting on.
Power over Ethernet
The other quiet advantage. A network cable can carry electrical power as well as data, so a single run from a switch to the camera does both jobs. For a camera at the far end of a garden this collapses the whole wired-or-wireless problem described in Wired or wireless camera? into one cable — which is why, in the end, the most convenient network camera installation is usually a wired one.
What it means in a bird box
In practice, an IP camera in a nest box gives you a sharper picture than an analogue one, recording on a memory card in the camera itself, remote viewing on a phone, and no television involved anywhere. What it costs you is a little configuration and a dependency on your home network. The full walkthrough for the camera Handykam sold is in the WIFI IP camera FAQ, and the trade-off against analogue is weighed up in Digital IP versus analogue CCTV cameras.