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Key Functions of NVRs in IP Surveillance

A network video recorder (NVR) is crucial to any type of IP surveillance system. Security cameras can be installed to deter potential burglaries and provide reliable cues for security investigations, but the NVR is where all important data and footage end up. It can record both video and audio and handle multiple IP cameras at once.

What is an NVR?

The NVR is an IP camera recording system that records video footage and stores it in a hard drive disk, cloud storage or other mass storage device. It provides a centralized video control to allow you to easily view, record and manage the footage. The NVR gives you more flexibility on the installation site since the cameras don’t need to be hardwired to the recorder (they only need to work on the same wireless network). However, it’s relatively more expensive since it’s greatly improved with various features like remote monitoring and dual-monitor displays (HDMI & VGA).

Key Functions of NVRs

Live Stream——The most basic function of the NVR is to provide remote access to real-time footage of your IP cameras via digital Internet Protocol so you will have cameras automatically displayed on the monitor once successfully connected. The camera will send out two video streams to the recorder: mainstream and substream. The mainstream is of high resolution and high bitrate, the exact quality the NVR records at. On the other hand, the substream is the secondary stream coming from the camera to the recorder that comes with a lower resolution and bitrate. And live viewing is normally going to be the substream of video feeds to reduce the load on decoding. But the NVR can still record on mainstream quality even when streaming the substream.

Video Storage——Another important feature of all video recorders (either DVR or NVR) is their ability to store the footage captured by the cameras. The recorder can manage and control the data flows of multiple IP cameras and upload it to the monitor screen or a computer where you can edit the footage whenever you want. As previously discussed, the NVR will record the footage at the higher-quality mainstream, and more detail will be expressed. It also enables its users to take backup of the recordings manually when needed.

Playback——Many times, it’s not always possible for a property owner or a security guard to monitor the premise in real time. But with the playback function, you can view the footage captured by the surveillance cameras at any time and search through footage by camera, date, time, and media type once you log in to your account. Assuming that a burglar breaks into your house when you’re away, these recorded videos could serve as strong evidence to help local police arrest the suspect. Furthermore, thanks to the playback feature, you will never bother to hire a security guard to scout your premises 24/7 to protect your home and business.

Classification of NVRs

NVRs can be classified into different types according to their specifications and features.


According to the functions of PoE, NVRs can be divided into regular NVRs and PoE NVRs. The NVR only provides basic features like live viewing, video recording, playback, etc. It offers a centralized video control to allow you to store and process the captured footage. The PoE NVR is a video recorder that has a built-in PoE switch. It can deliver power and data to the IP cameras at the same time, eliminating the need for installing an external PoE switch. The PoE NVR can connect three or four IP cameras at a time (hardwired), ideal for users with minimal network administration experience and small networks like start-up businesses.

On-Premise NVR vs. Cloud-Based NVR

The on-premise NVR normally stores the footage on a hard drive disk, so when the device breaks, all the data will be gone. But you don’t have to pay for subscriptions every month as you will when using a cloud-based NVR. The cloud-based NVR is a recorder that stores data in the Cloud. It can be securely accessed anytime, anywhere and from any authorized device to ensure you can gain 24/7 access to the cameras. Cloud storage also allows you to easily expand to more cameras. The cloud-based NVR allows you to store the data for such a long time that even if the device fails the data will remain. And all the data will be stored in an encrypted form.

How to Pick the Right NVR for IP Surveillance System?

Here, we’ve included a buying guide to help you pick the best NVR for your system.

1. Channels and recording resolution

NVR can be classified by the number of channels (16/32/64) it supports so you have to make sure the NVR has more than the required number of channels. For example, if you plan to install 4 IP cameras at once, it’s suggested to choose an 8-channel NVR for future expansion. Moreover, recording resolution is also essential to set up a high-definition video surveillance system. Higher resolution means greater amounts of detail, but accordingly, larger file sizes will be generated. Some NVRs will support high-resolution recording in all channels, while others only have HD available in 1-2 channels.

2. Interoperability

Unlike the DVR system which shows high interoperability in mixing and matching cameras from different brands, some NVRs can only support IP cameras from the same brand. So it is essential that the NVR is onvif-compliant or supports PSIA protocols to allow the NVR to work with different-branded cameras. Most IP cameras are now onvif-compatible, but if you want to stick to your existing cameras, it’s recommended to choose an NVR that comes with high interoperability.

3. Storage capacity and video compression

Storage capacity also plays an important part in video surveillance. Apart from local storage with the built-in HDDs, the NVR should support Cloud/software storage for video archiving with external storage options (USB/eSATA interfaces). To attain high-quality compressed files, you should pick an NVR that supports the latest video compression standard of H.265 (HEVC) to deliver the highest-quality images at lower bit rates (50% reduced) with greater coding efficiency, which drastically reduces the storage and bandwidth requirements, making high-quality video compression more affordable.

4. Other Advanced functions

Apart from the basic storage and playback functions, the NVR should have audio and alarm interfaces to help you incorporate the video surveillance system with other security devices like detection sensors or security alarms. Some recorders are greatly improved with multiple smart features like remote control, real-time message alerts and dual-monitor display (HDMI & VGA). Furthermore, 64-Ch Network Video Recorder from FASTCABLING also supports local management with extra USB interfaces to operate with a USB mouse and keyboard.

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