Security cameras use your internet in two ways: when someone views them remotely, and when they record to the cloud. Both use upload, not download. Cameras recording to an on-site recorder use almost no internet at all until someone watches from outside. Cameras recording continuously to the cloud need upload equal to the combined bitrate of every camera, all day, every day. Work out which model you have, add up the bitrates, and compare the total with your circuit's upload speed, not its headline download number.
Camera systems are often installed by a security company and the internet by someone else, and nobody adds the two together. The first sign of trouble is usually a video call that breaks up, a slow cloud backup, or cameras that drop off the app when someone needs them. A few minutes of arithmetic before the install prevents all of it.
Where the video goes decides the bandwidth
| Recording model | Inside the building | Internet upload used |
|---|---|---|
| On-site recorder (NVR), no remote viewing | Every camera's full stream to the recorder | Almost none |
| On-site recorder with remote viewing | Same | Only while someone is watching, usually a lower-quality stream |
| Cloud recording, motion or event only | Some, depending on design | Bursts when motion is detected, plus small status traffic |
| Cloud recording, continuous | Some, depending on design | Every camera's stream, all the time |
| Hybrid: record locally, send clips to the cloud | Every camera's full stream to the recorder | Clips and events, plus remote viewing |
Ask the security vendor which of these your system uses. The answer changes the internet requirement more than anything else. Inside the building the picture is different: every camera's full stream crosses your switches to the recorder all day, which is one more reason to give cameras their own network segment and wired connections.
Typical bitrates, and why they vary
A camera's bitrate is how much data its video stream produces each second. It depends on several settings and on what the camera is looking at, so manufacturers' figures and real-world numbers often differ. As a rough guide, the ranges below are typical; treat them as a starting point, not a specification.
| Resolution | Typical range, H.264 | With H.265 |
|---|---|---|
| 1080p (2 MP) | Roughly 2 to 6 Mbps | Often noticeably lower |
| 4 MP | Roughly 4 to 8 Mbps | Often noticeably lower |
| 4K (8 MP) | Roughly 8 to 16 Mbps or more | Often noticeably lower |
What moves the number:
- Codec. H.265 is designed to compress video more efficiently than H.264, so it usually needs less bandwidth for similar quality. How much less depends on the camera and the scene. Some vendors add their own "smart" compression modes on top.
- Frame rate. Fifteen frames per second is common for security; thirty uses more.
- Scene and lighting. A busy street, trees moving in wind or a dark scene with grainy infrared footage all push the bitrate up, because there is more change to encode.
- Variable or constant bitrate. Variable bitrate saves bandwidth when the scene is quiet and spikes when it is busy. Plan for the busy hours.
The most reliable number is the one your recorder or cloud dashboard reports for your cameras, at your site, during your busiest hour.
Main streams and sub-streams
Most IP cameras send two streams at once: a high-quality main stream for recording and a smaller sub-stream for live viewing on a phone or a grid of thumbnails. Remote viewing usually uses the sub-stream, which is often well under the main stream's bitrate. When someone taps on one camera to see it full screen, the app may switch to the main stream for that camera.
The arithmetic
Upload for continuous cloud recording
Add up the bitrate of every camera recording to the cloud. That total is the upload used around the clock, before anything else in the business uses the connection. Leave headroom on top for staff, phones and cloud apps, which also need upload.
Upload for remote viewing
Multiply the number of camera streams likely to be viewed at the same time by the sub-stream bitrate, then allow for someone opening one camera at full quality. For most small businesses, remote viewing is modest compared with cloud recording.
Storage
Storage follows the same numbers. A stream of 4 Mbps produces 4 megabits a second, which is half a megabyte a second, or 1.8 GB an hour and about 43 GB a day. Multiply by the number of cameras and the days of retention you want, then check whether your recorder's drives, or your cloud plan, actually hold that much.
Why upload speed is the bottleneck
Many business internet plans, especially coax, are asymmetrical: download is much faster than upload. A plan with fast download and a fraction of that in upload can look generous on paper and still choke on a dozen cameras recording to the cloud. Fiber plans are more often symmetrical, with the same speed both ways. Our guide to symmetrical vs asymmetrical internet explains the difference, and the business speed test guide shows how to measure what you really get.
Cameras are also a constant load. Most office traffic is bursty: a file upload here, a video call there. Our guide to how much bandwidth your business needs covers sizing for everything else on the line. A cloud camera system sends data every second of every day, which leaves less room for those bursts and can make calls and meetings worse at exactly the times staff are busiest.
Designing the network for cameras
- Put cameras on their own VLAN, with access only to the recorder and the cloud service they need. Cameras are often among the least patched devices on a network. Our guide to VLANs and network segmentation covers the layout.
- Check the PoE budget on the switch that powers them, especially for outdoor cameras with heaters or infrared lights. See managed vs unmanaged switches.
- Do not open recorder ports to the internet. Port forwarding to an NVR is a common way cameras get compromised. Use the vendor's secure remote access service or a VPN.
- Cap or schedule cloud uploads if the system allows it, and use quality of service so voice traffic goes first.
- Watch the backup connection. If the main line fails over to a cellular backup with a data allowance, continuous cloud recording can use it up. Set the system to record locally or pause cloud uploads while on backup.
- Wire them. Wi-Fi cameras share airtime with everyone else. Wired PoE cameras are more dependable and do not slow the Wi-Fi.
A worked example
Hypothetical: the business, camera count, bitrates and circuit are invented to show the arithmetic. Your vendor's figures and your own measurements decide the real numbers.
A retail store with a stockroom plans 12 cameras at 4 MP. Its current internet is a coax plan with fast download and 35 Mbps upload. The security vendor offers two options.
Option A, continuous cloud recording. Say each camera averages 4 Mbps on H.265 in this store's lighting. Twelve cameras need 48 Mbps of upload all day. That is more than the circuit's entire upload, before the card terminals, the phones or the manager's video calls. Option A needs either a different circuit or a lower recording quality.
Option B, on-site recorder with cloud clips. All 12 streams go to a recorder in the stockroom over the local network, using no internet. The system uploads motion clips after hours and supports remote viewing. If two managers each watch four cameras on sub-streams of around 0.5 Mbps, remote viewing uses about 4 Mbps, comfortably inside the upload.
Storage on the recorder: 12 cameras at 4 Mbps is about 43 GB per camera per day, or around 520 GB a day for the store. Thirty days of retention needs about 15.5 TB, so the recorder needs drives of that size or more, or a shorter retention period, or motion-only recording on the quieter cameras.
If the owner prefers Option A for its off-site copy, the store needs a circuit with much more upload. Symmetrical fiber would carry it with room to spare, if it is available at the address. Either way, the decision is made before the cameras go up, not after the first slow afternoon.
Questions to ask your security vendor and your provider
- Do the cameras record to an on-site recorder, the cloud, or both?
- What is each camera's average and peak bitrate at our settings?
- Which codec do they use, and is H.265 supported end to end?
- How does remote access work, and does it require opening ports on our firewall?
- Can cloud uploads be capped, scheduled or paused when we are on backup internet?
- What upload speed does our circuit actually deliver, and is a symmetrical option available at our address?
Getting the upload right
We price circuits across several Tier 1 carriers for your exact address, including shared fiber options that are often symmetrical, so you can compare upload speeds before the cameras go in. Our managed network service can set up a separate camera segment and monitor it. The carrier pays FiberX, so there is no markup, and if your current circuit already has the upload you need, we will tell you. The quote is free with a same-day response, and Phil Morales is your one point of contact. Send us your camera plan and address, call 478-758-8091 or text (347) 870-0965.
