CCTV Technical FAQs: NVR, DVR, PoE, Storage & 4K

Clear answers to common CCTV technical questions about NVRs, DVRs, PoE cameras, surveillance storage, 4K video, audio, cabling and remote viewing.

What is the difference between an NVR and a DVR?

An NVR (Network Video Recorder) is normally used with IP cameras that send video over a network connection. A DVR (Digital Video Recorder) is normally used with analogue cameras connected by coaxial cable. For a new IP installation, an NVR is usually the relevant recorder; for an existing analogue installation, a DVR may allow you to keep compatible coaxial cabling.

What does PoE mean in CCTV?

PoE means Power over Ethernet. A compatible PoE camera can receive both data and electrical power through one Ethernet cable, usually Cat5e or Cat6. This can simplify installation because a separate power adaptor is not required at each camera.

Are PoE cameras better than Wi-Fi cameras?

For fixed CCTV installations, PoE is usually more predictable because the camera has a wired data connection rather than depending on Wi-Fi signal strength. Wi-Fi cameras can still be useful where cabling is difficult or the installation is temporary. See our Wi-Fi CCTV vs Wired CCTV guide for a fuller comparison.

Do I need an NVR for PoE cameras?

Not in every possible setup, but an NVR is the normal choice for a multi-camera PoE CCTV system because it provides central recording, playback, camera management and remote access. Some IP cameras also support local microSD storage or other network recording methods.

What size hard drive do I need for CCTV?

Storage depends on camera count, resolution, frame rate, compression, recording mode and how many days of footage you want to retain. Higher resolution and continuous recording use more storage. For 24/7 CCTV recording, use a surveillance-rated hard drive and calculate capacity for the actual system rather than choosing only by camera count.

What is the benefit of a 4K or 8MP CCTV camera?

4K is approximately 8 megapixels and can provide more image detail than lower-resolution video. That extra detail can help when reviewing faces, vehicles or activity, but it also increases bandwidth and storage requirements. The recorder, display and network should all be suitable for the resolution you intend to use.

Why can a 4K NVR show no picture on an older TV or monitor?

A common cause is an output-resolution mismatch. If the NVR is set to a resolution the display cannot accept, the recorder may be working normally while the screen shows no signal. Connecting a compatible display and lowering the NVR output resolution can restore the picture. Lowering the display output does not necessarily mean the cameras must record at the same lower resolution.

Can CCTV cameras record audio?

Some cameras include a built-in microphone, and some models also support two-way audio with a microphone and speaker. Audio support depends on the exact camera and recorder. When recording audio, you should also consider the applicable privacy and data-protection requirements for the installation.

What does IP67 mean on a CCTV camera?

IP67 is an ingress-protection rating indicating a high level of protection against dust and water. It is common on outdoor CCTV cameras, but installation still matters: cable joints, connectors and junction boxes should be properly protected from weather.

Can fibre optic cable be used for CCTV?

Yes. Fibre is useful for long-distance network links, large sites or links between buildings. A common design is a fibre backbone between network switches, with PoE delivered locally from a PoE switch to the cameras. Fibre itself does not provide PoE power to a standard camera.

Can I view an NVR or DVR on my phone?

Many modern recorders support remote viewing through a manufacturer app when the recorder is connected to the network and remote-access settings are configured correctly. For ANNKE equipment, see our ANNKE Vision app setup guide.

Why should CCTV use a surveillance hard drive?

Surveillance drives are designed for continuous video-recording workloads and multi-camera operation. For an NVR or DVR expected to record around the clock, a surveillance-grade drive is generally a more appropriate choice than a normal desktop drive.

Delivery, returns, warranty and support

For non-technical questions about ordering, local delivery, returns, warranty and customer support, see our HawkVision Pro customer FAQ.

If your problem is not covered here, contact HawkVision Pro with the camera or recorder model and a description of the fault.