A leased line for CCTV and remote monitoring

Why CCTV is hard on an ordinary connection

Most internet use is bursty: people download a page, then read it. Cameras are different. A camera that records to the cloud sends its video up the line continuously, and every extra camera adds another stream. That creates three problems on a typical broadband connection:

• Upload runs out first. Broadband upload is often a fraction of its download, and a few cameras can use most of it.
• Cameras compete with staff. While footage takes the upload, calls, video meetings and file saves slow down.
• Busy periods hit everything. On a shared, contended service, performance can fall at busy times, which can mean dropped frames or gaps, depending on how your system buffers.

A leased line gives you a fixed amount of upload that is not shared with other customers, so you can plan cameras and staff traffic side by side.

What BTnet offers CCTV

• Symmetrical upload. Upload matches download, so a 100Mbps port gives 100Mbps up as well as down. See symmetrical internet speeds.
• Uncontended bandwidth. BT describes BTnet as 100% uncontended and dedicated to your site.
• No fair usage policy. BT's help pages say you can use as much data as you need, which matters for footage that runs around the clock.
• Static IPv4 addresses. Included as standard, which makes secure remote viewing and allow-listing practical. See static IP addresses.
• BT's SLA. An availability service level with service credits under BT's terms. See the BTnet SLA.
• Room to grow. Add cameras later and change speed within your bearer with Bandwidth Flex.

Local recording, cloud recording or both

How much of your CCTV crosses the leased line depends on where footage is recorded. Ask your camera or security supplier which of these you have, or plan to have:

Cloud recording puts the most continuous load on the line, so it gains the most from a leased line. Local recording is lighter on the connection but still benefits from a fixed address and reliable upload when someone needs to see live footage.

Sizing upload for your cameras (illustration)

The method is simple: take the bandwidth of each camera's stream from your camera or video system supplier at the resolution, frame rate and compression you plan to use, multiply by the number of cameras, then add remote viewing and a margin. Settings change bandwidth a great deal, so the supplier's figure for your set-up is the one to use.

The figures below are made up to show the arithmetic. Suppose, for illustration only, your supplier says each camera's recording stream uses 4Mbps at your chosen settings:

That upload runs all day, so it sits on top of everything else the site sends at its busiest hour. Add a margin for overheads, which BT's terms put at typically 5-10% below the port speed, and for growth. Our bandwidth sizing guide shows how to combine cameras with calls, cloud apps and backups.

Remote viewing, static IPs and security

Being able to view cameras from anywhere is useful, and it is also a common route for attackers if it is set up carelessly. Good practice for any CCTV system on a leased line:

• Do not expose recorders openly to the internet. Reach them through a VPN or the supplier's secure remote access, and use your static IP addresses to allow-list who can connect.
• Keep cameras on their own network. A separate network segment stops a compromised camera reaching office systems.
• Change default passwords and keep firmware updated, as your camera supplier recommends.
• Add network protection. With Meraki managed equipment, BTnet Security adds intrusion detection and prevention, content filtering and malware protection. BT's terms say it does not guarantee security against unauthorised access, so treat it as one layer.

Under BT's terms the static IP addresses BT provides stay with the service and end when it ends, so keep a note of where they are configured in case you move. See moving office with a BTnet leased line.

Alarms, building systems and other monitoring

Cameras are rarely the only devices watching a site. Access control, building management, environmental sensors, production equipment and remote support tools all use the connection, often around the clock and often needing a fixed address so they can be reached securely.

A leased line gives these systems steady, symmetrical capacity, but check each one's requirements with its supplier. Monitored intruder and fire alarms in particular may have their own signalling rules, so ask your alarm company what their equipment needs. If alarms or other special lines currently use traditional phone lines, our sister site explains alarm and special lines in the PSTN switch-off.

Questions to ask your camera supplier

Your camera or security supplier holds most of the numbers you need to size the line. Before you ask us for a quote, it is worth getting answers to these:

• Where is footage recorded: on a recorder at the site, in the cloud, or both?
• What does each camera send over the internet at the resolution, frame rate and compression you will use, and does that change at night or when motion is detected?
• How many people view footage remotely at once, and from where?
• What happens during an outage: do cameras or recorders store footage locally and upload it later?
• How is remote access secured, and which addresses or ports need to be allowed through your firewall?
• Do the cameras need power over Ethernet, and how many switch ports and how much power will that take?

With those answers, sizing becomes straightforward arithmetic, and we can match the camera load to a port speed with room to add cameras later.

Keeping footage flowing

If footage matters for safety, insurance or evidence, think about what happens when the line or the power fails:

• A second line. BT offers failover, load-balancing and lower-speed back-up options for BTnet. A back-up sized for the cameras and essentials can be enough. See resilient BTnet.
• Local buffering. Ask your supplier whether cameras or recorders store footage locally during an outage and upload it afterwards.
• Power. Cameras are often powered from network switches. Put the recorder, switches and router on backup power, and remember that BT's terms ask you to provide a secure power supply for BT's equipment.

Contact us with your camera count and recording set-up, and we can help you size the line, the plan and any resilience. If you are fitting cameras at a new site, read about site surveys first, because the line can take longer to arrive than the cameras.