Cloud video surveillance: what it is, what it needs and when it makes sense

With cloud video surveillance, camera video is stored on a provider's servers on the internet, and you watch or search it through an app or a web page. It is also sold as video surveillance as a service, or VSaaS.

The name covers different products. Some services record everything from every camera. Some save only short clips when something moves. Some need their own cameras, and some work with ordinary cameras through a small box on your site. So the first job is to ask what actually goes to the cloud.

There are three ways to keep camera video. Most real systems are one of these or a mix.

• Local recording. Cameras send video to a recorder (a DVR or NVR) or to an SD card on your site. The video stays on your own network, and the internet is used when someone watches from outside. You look after the recorder, its disks and who can get to it. If the recorder is stolen, damaged or burnt, the footage goes with it.
• Cloud recording. Video goes over the internet to a provider and is stored there. That gives you an off-site copy. One camera maker's cloud page says the point is to keep your video even if your device is stolen or the memory card breaks. In return you need enough upload speed, and you usually pay a subscription.
• Hybrid. Recording happens on site, and some of it is also copied to the cloud, often only event clips. For example, one camera maker's cloud plan records to the camera's SD card and to the cloud. The word hybrid is used loosely, so ask each provider what exactly goes up, in what quality and for how long.

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Cloud recording sends video out of your building, so the speed that matters is upload speed. Your internet plan lists upload and download speeds separately. The US regulator, the FCC, says that upload speed is the speed of sending information to the web, and that service providers generally do not offer upload speeds as high as download speeds. It also notes that some providers cap the total data you can send or receive.

Next, work out what your cameras send. Each camera stream has a bitrate, shown in the camera's or recorder's settings in megabits per second (Mb/s). One camera maker's white paper lists what changes it: the video codec, the resolution, the frame rate, the compression level and the scene. Motion in the scene can raise the bitrate a lot.

Then do the sums. Multiply the number of cameras by each camera's bitrate. For example, eight cameras at 2 Mb/s each need 16 Mb/s of upload, all day and night. A stream of 1 Mb/s that never stops is about 10.8 GB a day, so those eight cameras send about 173 GB a day, or about 5.2 TB in 30 days. The 2 Mb/s is only an example, so use your own cameras' numbers.

This is why many cloud plans do not record everything. One camera maker's current cloud plan, for example, saves motion event clips and not continuous video, and records up to 2K even from 4K cameras. The camera still records to its own card at full resolution.

Two more points. A cloud-only service has nothing to record to while your internet is down, unless the camera also records to its own card. And on a site with no fixed line, you need a 4G or 5G router and a data plan, where live video from many cameras uses a lot of data and a single still photo uses far less.

Video of people is personal data in many places, so it needs looking after. The UK data protection regulator, the ICO, says footage must be stored securely, with access limited to authorised people, and that encryption can be an effective way to stop unauthorised access. If you use a cloud provider, the ICO says to check that it offers enough security, and whether sending the data to a provider abroad counts as an international transfer.

The ICO also says UK law sets no fixed period for keeping surveillance footage. You keep it for the shortest period you need for your purpose, and not for months just because the system allows it. For comparison, Secured by Design, a UK police initiative, says a system meant to support prosecution should be able to store 31 days of footage.

Rules on recording, signs, sound and notice to staff differ by country, and by state in the US and Australia. Check the rules where your cameras are.

Cloud or not, the basics apply. The UK's National Cyber Security Centre says to change default passwords, keep camera software updated and switch off remote viewing you do not use. It also advises switching off UPnP and port forwarding on home routers, because criminals can exploit them. Questions to ask any cloud provider:

• Where in the world is my video stored?
• Is it encrypted while it travels and while it is stored?
• Who at the provider can see it, and when?
• How long is it kept, and can I choose a shorter time?
• Can I delete it, and can I download it before I leave?
• Does the account offer two-step sign-in?
• What happens to my video if I stop paying? One camera maker's plan says access to cloud recordings stops when the subscription ends, so you download what you want to keep first.

None of these is best for everyone. Here is a fair summary of each.

• Cloud recording suits a few small sites with nobody to look after a recorder, and anyone who wants an off-site copy that survives theft of the equipment. Watch out for upload speed, a subscription for each camera, a limited choice of cameras, and what is actually uploaded.
• Local recording suits many cameras at one site, longer retention and a connection with little upload. Watch out for who looks after the recorder, and for what happens to the video if the recorder is lost.
• Hybrid suits sites that want full video kept on site and a copy of key moments kept off site. Watch out for hybrid as a label rather than a design. Ask what goes up, and how much.

Prices vary too much by country, plan and number of cameras for one figure to help, so we will not make one up. What you can do is know what moves the number, so that quotes can be compared fairly.

• How many cameras. Cloud plans are often priced per camera or per group of cameras at one location. One camera maker, for example, sells a single-camera plan and a multi-camera plan for up to 10 cameras at one location, each monthly or yearly.
• How long video is kept. Longer storage costs more.
• What goes up. Continuous video usually costs more than event clips, and higher resolution usually costs more than lower.
• Your internet. Cloud recording may need a plan with more upload, or a data plan on 4G or 5G.
• Which cameras work. Some services work only with certain cameras. One maker's current plan covers a short list of its camera models and, per its own help page, not yet its recorders.
• Contract terms. Monthly or yearly, the notice to cancel, and what happens to your video afterwards. One maker's help page says returning a device does not cancel the subscription, so cancel it separately.
• Local recording costs too. A recorder, hard disks, replacing the disks, and someone's time to check that it is recording.
• Whether people watch. A service where people watch your video adds a recurring fee on top. Our remote video monitoring guide explains it.

We are not a cloud recording service. We work with the cameras and recorders you already have: Hikvision, Dahua, Axis, Hanwha, Uniview, TVT, and any camera, DVR or NVR that offers RTSP or ONVIF. Our software runs on a Windows PC at your site and installs in 60 seconds.

Detection happens on site. The software watches every camera for smoke and fire, people after hours in zones you mark, and a camera that has been covered. Your recorder keeps recording as usual, so your recordings stay on your recorder.

When something is found, the event photos and clips go to the cloud, where a second, larger model double-checks every event before you are alerted. Then we send you the photo on WhatsApp, Telegram or the Foreman app while it is still happening. Event clips are encrypted and deleted after 30 days. So the heavy video stays on your network, and only the moments that matter go up. There is no all-day upload to plan for.

Here is the limit. We do not keep your full recordings. If you want an off-site copy of all your video, so that it survives a stolen or burnt recorder, you need a cloud recording service or a second recorder somewhere else. We also do not provide guards or a monitoring centre, and where we watch for smoke and fire, we do not replace certified fire alarms or life-safety systems.