NVR or DVR? What you need for an Ajax camera system
An Ajax camera system needs an NVR, not a DVR. A DVR (digital video recorder) records analogue or HD-over-coax cameras. An NVR (network video recorder) records IP cameras over network cable. Ajax makes only IP cameras and NVRs, so its TurretCam, BulletCam and DomeCam Mini cannot plug into a DVR's coax inputs, and coax cameras will not work on an Ajax NVR. Below: which Ajax NVR to choose, what else to buy and when to keep your DVR.
Our CCTV buying guide and our article on analogue vs IP CCTV compare the two in general. This post covers the Ajax questions.
How does an NVR differ from a DVR in practice?
With a DVR, the camera sends an analogue signal down the coax and the recorder encodes it. With an NVR, the camera does that work and sends a compressed stream over the network. That explains the differences:
- Power: an IP camera can take power and data on one network cable (Power over Ethernet, or PoE). Coax cameras usually need a separate supply unless the kit supports power over coax.
- Sound: Ajax's wired cameras have a built-in microphone, and the audio travels on the same cable.
- Detection: Ajax's wired cameras recognise people, pets, vehicles and line crossing inside the camera.
Why does Ajax make only NVRs?
Every recorder in Ajax's video catalogue is an NVR, and it has no coax cameras. Its cameras are network devices from the start: Ajax's specifications list an encrypted connection (mTLS), Secure Boot and signed firmware updates. They also follow ONVIF, the standard that lets different makers' cameras and recorders work together:
- Profile S (announced by Ajax on 31 March 2025): live video and audio streaming, for the NVR, wired cameras, IndoorCam and DoorBell.
- Profile G (announced on 31 July 2026): another ONVIF recorder or video management software can search and play back footage stored on Ajax wired cameras and NVRs. It needs camera firmware 2.901 and NVR firmware 2.751 or later. DoorBell and IndoorCam are not covered.
Ajax says H.265 and its motion and AI events work over ONVIF but outside conformance, so test them with the other system.
Which Ajax NVR do you need?
We list five Ajax recorders. Each takes one SATA hard drive of up to 16 TB (2.5 or 3.5 inch), sold separately.
| Recorder | Cameras | Screen output | Power | Price inc VAT |
|---|---|---|---|---|
| Ajax NVR, 8 channels | 8 | None: view in the Ajax app | Mains | £199.22 |
| Ajax NVR, 16 channels | 16 | None: view in the Ajax app | Mains | £252.25 |
| Ajax NVR DC, 8 channels | 8 | None | Low-voltage DC | £199.22 |
| Ajax NVR HAC, 8 channels | 8 | HDMI, up to 1080p | Mains | £230.26 |
| Ajax NVR HAC, 16 channels | 16 | HDMI, up to 1080p | Mains | £289.77 |
Prices include VAT, delivery is extra, and prices can change.
- The HAC, from Ajax's NVR H series, adds HDMI for a monitor and two USB ports for a mouse, keyboard or memory stick. Ajax says on-site viewing works without internet, provided the cameras reach Ajax Cloud at least once every 30 days.
- The standard NVR suits viewing in the Ajax app only.
- The NVR DC runs from an 8 to 16 V DC supply.
What else does an Ajax camera system need?
- A PoE switch: none of these NVRs has PoE ports, so power the cameras from a switch (802.3af/at) or a 12 V supply. Compare the cameras' total draw with its PoE budget: eight BulletCam HL 5MP cameras draw up to 7.3 W each, about 58 W in all. See our PoE switches.
- Network cable: a Cat5e or Cat6 run from each camera to the switch.
- A hard drive: size it with our CCTV storage calculator, then choose one of our surveillance hard drives.
- An Ajax hub, only if you want the alarm linked: with an Ajax wireless alarm, its detectors can make chosen cameras record and send the clip to the app.
Will 16 high-resolution cameras fit on one NVR?
Check bandwidth as well as channels. Ajax rates the standard NVR at up to 100 Mbps of incoming video and the NVR HAC at 80 Mbps. Our worked example uses our storage calculator's starting bitrates for H.265 at 25 frames per second: about 4.6 Mbps for 5MP and about 8 Mbps for 8MP.
| Cameras | Total bitrate | Standard NVR (100 Mbps) | NVR HAC (80 Mbps) |
|---|---|---|---|
| 8 × 8MP | about 64 Mbps | Fits | Fits |
| 16 × 5MP | about 74 Mbps | Fits | Fits, near the limit |
| 16 × 8MP | about 128 Mbps | Over | Over |
If you are over, lower the bitrates, use 5MP models in some positions or split the cameras across two recorders. Busy scenes such as roads and trees need more, so leave room.
Can you keep your existing DVR?
Yes, though not as the recorder for Ajax cameras:
- Keep it alongside: leave the coax cameras on the DVR and put new positions on Ajax cameras and an NVR. Ajax says a third-party recorder can join a system with an Ajax hub as one device, with each camera's stream in the app. Ajax names only some makes and does not mention playback, so treat this as live viewing and check your DVR is supported.
- Replace it: run network cable to each camera position and move fully to IP.
Keep the DVR if the coax is in place, the pictures are good enough and you do not need cameras linked to an alarm. Move to Ajax if you are recabling anyway, the recorder is failing, or you want in-camera detection, sound and alarm-triggered clips in one app.
Is an IP recorder safe on your network?
The UK rules and guidance:
- Product law: since 29 April 2024 the UK's PSTI regime has banned guessable default passwords on connectable consumer products and made makers publish how long security updates will last. Ajax lists PSTI UK compliance on its NVR specifications.
- Set-up: the National Cyber Security Centre (NCSC) advises changing default passwords, keeping firmware updated, turning off remote viewing you do not need and considering disabling UPnP and port forwarding on the router. Ajax adds that streams shared through ONVIF or RTSP need strong, private passwords.
- Sound: the ICO says audio is more intrusive than video and should be off by default unless justified. Ajax's wired cameras have microphones, so decide at set-up.
- Coverage: for homes, the ICO says data protection law applies once cameras capture anything beyond your boundary.
Our take
With Ajax cameras, the natural recorder is an Ajax NVR. The real decision is the standard NVR for app-only viewing or the NVR HAC for a monitor on site, then a check of PoE budget and bandwidth. A working DVR need not go on day one: it can keep its coax cameras while new positions go on Ajax.
Zenith Security Co. has supplied security equipment since 2012. We supply Ajax cameras and recorders rather than fit them, and we can recommend a qualified installer depending on the job and area. Browse all Ajax cameras and NVRs or everything we stock from Ajax.
Want a parts list checked? Call 01902 902251, contact us online or visit our Wolverhampton trade counter. We ship nationally to England, Scotland and Wales.
NVR or DVR: quick questions
Can I plug Ajax cameras into my DVR?
Not into its coax inputs. Ajax cameras are IP cameras: they record to an Ajax NVR, another ONVIF recorder or their own microSD card.
Does the Ajax NVR power the cameras?
No. The models we list have no PoE ports; use a PoE switch.
Can I watch Ajax cameras on a TV or monitor?
Yes, with the NVR HAC and its HDMI output of up to 1080p. With the standard NVR you view in the Ajax app.
Do I need an Ajax alarm to use Ajax cameras?
No. Ajax says spaces with only cameras and NVRs work without a hub. You need a hub and Ajax detectors only if you want the alarm to trigger recordings.
Source: Ajax Systems blog: NVR vs DVR, with Ajax's NVR H page, its NVR, NVR HAC and BulletCam HL specifications, its ONVIF Profile S and Profile G announcements, its camera connection FAQ and its video without a hub article; GOV.UK's PSTI product security regime, the NCSC's smart security cameras guidance and the ICO's home CCTV and video surveillance guidance. Device figures are Ajax's own.
