How each system is wired
An IP system uses Cat6 network cable from each camera to a PoE switch or a PoE NVR. One cable carries video, power and control. An HD analogue system (often sold as AHD, TVI or CVI) uses coaxial cable for video and a separate pair of wires or a combined 'siamese' cable for 12V power from a power supply box.
Image quality and features
Both types are available in 2MP (1080p) to 8MP (4K). IP cameras more often include features such as built-in microphones, smart motion detection that separates people and vehicles from moving trees, and line-crossing alerts.
Distance and cabling limits
A single run of network cable is limited to about 100 metres between devices; longer runs need a switch in between or fibre. Coaxial cable for HD analogue can often run further, which is one reason it remains popular on farms and large compounds.
Storage: how long will recordings last?
Storage depends on resolution, compression and how many hours each camera records. As a rule of thumb, one camera streaming at 4 Mbps continuously uses about 43 GB per day. H.265 compression and motion-only recording can cut that substantially. Tell the installer how many days of footage you want to keep and size the hard drive from that.
Frequently asked questions
Can I mix IP and analogue cameras?
Many hybrid DVRs (often called XVR) accept both HD analogue cameras and a limited number of IP cameras, which is useful when upgrading in stages.
What does PoE mean?
Power over Ethernet: the camera receives its power through the same network cable that carries the video, so no separate power point is needed at the camera.