Short answer
What matters in remote viewing is the upload speed of the internet where the camera is located. When you watch live on a phone, the recorder usually sends the low-resolution sub-stream, so a modest upload speed is enough for a few cameras. Downloading recordings remotely in high resolution, or watching many cameras at full quality at the same time, needs much more upload speed.
Look at upload speed, not download speed
Internet plans are usually sold by download speed: 50 megabits, 100 megabits. But when you watch your cameras remotely, the data flows the other way. The picture leaves the recorder at the shop or home, is uploaded to the internet and downloaded to your phone. The bottleneck is the upload speed where the camera is located.
On home and small business connections, the upload speed is often a small fraction of the download speed. So a 100-megabit plan can mean an upload capacity of only a few megabits for cameras. Find out your plan's upload value from your bill or your internet provider. Also run the speed test from the network the recorder is connected to, using a wired computer; a Wi-Fi test can give misleading results.
Main stream and sub-stream: the camera produces two pictures
Most IP cameras produce two separate video streams at the same time. The main stream is high resolution and is recorded on the recorder. The sub-stream is low resolution and is used for live viewing, multi-screen view and phones.
When you watch four cameras on one screen on your phone, the app pulls the sub-streams. Because these streams are small, they do not strain the upload line. But when you take a single camera full screen and switch to high quality, the main stream starts to arrive and the need suddenly grows. If the picture freezes or blurs, the app is most likely trying to show a main stream that does not fit the connection.
Expert note: You can adjust the sub-stream's resolution and bitrate yourself on the recorder. If you experience freezing on the phone, first lower the sub-stream a little; recording quality is not affected, because recording is made from the main stream.
How much data do resolution and compression produce?
The amount of data a camera produces depends on resolution, frames per second, type of compression and the amount of motion in the scene. A scene with tree branches swaying and vehicles passing produces far more data than an empty corridor.
H.265 compression produces noticeably less data than H.264 at the same picture quality. If your recorder and cameras support H.265, turning it on eases both the disk and remote viewing. The smart compression modes of some manufacturers reduce the data even more when there is no motion in the scene.
The exact bitrate varies with the camera and the setting. In your recorder's network settings you can see each camera's current bitrate; when planning remote viewing, add up these values and compare them with your upload speed.
- Upload speed of the line
- Cameras watched at the same time
- Sub-stream or main stream
- H.264 or H.265
- Motion in the scene
- Cloud recording
How much speed is needed in which situation?
Instead of giving an exact number, it is more correct to think in terms of how you use it. The situations below are ordered from light load to heavy load.
- Looking at the phone now and then, opening a few seconds of video when a notification arrives: a low upload speed is enough.
- Watching four to eight cameras live at the same time on sub-streams: the speed needed is the sum of as many sub-streams as there are cameras.
- Watching one camera at full quality and zooming in: the speed needed equals that camera's main stream bitrate.
- Playing back or downloading recordings remotely in high quality: the higher the speed, the faster it goes; at low speed it takes a long time.
- Continuously watching several branches from a head office: a separate upload speed and a stable connection are planned at each branch.
- Cloud recording: because the picture is uploaded outward all the time, it needs the highest and most stable upload speed.
If the speed is enough but the picture still does not come
Sometimes the speed test is fine but a connection cannot be made from the phone. A common reason is that the internet provider puts more than one subscriber behind the same external IP address. In this case direct access with port forwarding does not work. To get around this, the manufacturers of most recorders offer a P2P cloud connection; the device connects to the manufacturer's server, and the phone reaches the device through that server.
A similar situation exists on mobile connections. With construction site or field cameras that run on a 4G modem, P2P viewing usually works, but you need to watch the line's data quota. Continuous live viewing uses up the quota quickly.
For security, change the recorder's default password, keep its software up to date and do not open unnecessary ports to the internet. The ease of remote access also opens the device to the outside.
If the connection drops now and then, make sure the recorder and the modem are on the same UPS power source. During short power fluctuations, the connection is cut for a few minutes while the modem restarts. During this time recording continues locally, but remote viewing and notifications do not work.
On the phone side: mobile data and quota
Even if the upload speed where the camera is located is enough, the connection of the watching phone also counts. A 4G or 5G connection that gets good reception in the city carries sub-streams easily. If reception is weak on a village road or in a closed car park, the picture lags; this is the phone's problem, not the camera's.
The mobile data quota is also overlooked. Leaving the live picture of the shop open for half an hour at dinner can use up a significant part of the month's quota. Apps usually have a setting that automatically chooses low quality when using mobile data; turn it on.
Working with event notifications instead of watching continuously protects both your quota and your attention. When the camera detects motion or a person, a short notification and a small image arrive on your phone, and if needed you open that moment. Even a low upload speed is enough for this kind of use.
Check to do before installation
Before having a camera system installed, find out the upload speed of the internet line at your location and tell the installer. The installer sets the cameras' sub-stream settings accordingly. If the line is insufficient, the options include moving to a plan with a higher upload speed, moving to fiber if fiber infrastructure is available, or keeping recordings locally and checking remotely only through notifications.
The same bitrate also determines the disk need. On the disk calculator on our Tools page, you can enter the number of cameras, the resolution and how many days of recording you want, and see how much disk is needed.
In the systems it installs, Desa Bilişim sets up remote viewing by measuring the line's real upload speed, and also completes the phone app setup together with you at handover.
Frequently asked
Why does the picture freeze when I watch on my phone?
The most common reason is that the phone tries to pull the main stream at full quality and the upload speed where the camera is located is not enough for it. In the app, switch the picture quality to standard or smooth mode. If the problem continues, lower the sub-stream bitrate on the recorder.
Is internet needed for recording?
No. The recorder saves the picture coming from the cameras to its own disk over the local network. Internet is needed only for remote viewing, notifications and cloud backup. Even if the internet drops, local recording continues.
Do the same rules apply to a Wi-Fi camera?
Yes, and on top of that the wireless link between the camera and the modem is a separate limit. If the camera is far from the modem or there is a wall in between, the picture can degrade before it reaches the internet. Cloud-recording Wi-Fi cameras use the upload line constantly.
Let your cameras look smooth on your phone
Let's measure your line's real upload speed and set the camera and recording settings accordingly.
