CCTV-101, How Cameras work

This guide teaches the fundamentals of video management software.


Inside, we cover:

  • NVR vs VMS
  • Viewing Video – What are the common client features? Layouts? Camera Lists? Timeline?
  • Searching Video – How is video searched for? Time? Motion? Analytics? Thumbnails?
  • Exporting Video – How is video exported? File Format? Watermarks? Cloud? Mobile?
  • Camera Discovery/Addition – How are cameras discovered/added? Auto? Manual?
  • System Administration – How is the system configured? Recording? Users? Health?
  • Mapping Support – How are maps supported? Images? Hosted Maps? Dynamic?
  • VMS vs Low-Cost NVRs – What are the pros and cons of each? Cost? Features?
  • Installation Comparison – Why are NVRs easier to install? Training? Skills?
  • VMS Hardware Flexibility – How are VMSes more flexible and scalable? Open?
  • Widely Used VMSes/NVRs – What companies are widely used or notable?


The fundamental difference between Video Management Software and NVRs (or Network Video Recorders) is that NVRs preload and bundle the video management software in their appliances.

Secondarily, VMS software tends to offer greater functionalities than NVRs, though this is a rule of thumb, not required. Indeed, many VMS software providers offer their own NVR options for simplicity of deployment.

Viewing Video

The most common function of any surveillance system is viewing live and recorded video.

Surveillance video is viewed on software typically referred to as a “client”, which displays the video from cameras or recorders on screen. There are typically VMS clients that run on PC/workstations, web browsers, and smartphones.

Primary client interface features consist of viewing tiles, camera lists, control function menus, video timeline, instant replay features.

Viewing Tile Layouts

Viewing multiple cameras at the same time is a common live monitoring task. Viewing Tiles/Layouts allow for organizing views of multiple cameras (2×2, 3×3, 4×4) for quick access to what camera views are important or physically and operationally related to each other (e.g. all entrances, all parking lots, cafeteria cameras)


However, watching a lot of cameras simultaneously is difficult, and visible details can be lost as each camera is very small.

Camera Lists

Camera Lists allows for quick access to cameras for selection, however, in a larger VMS list can be difficult to visually search. Some VMSes offer organizing cameras alphanumerically and/or by building name/location, or a quick search bar for easier access


Common Control Function Menu

Control Function Menus offer quick access to common actions like Taking Snapshots, PTZ controls and Creating Bookmarks.


  • Snapshots: Because sometimes a still image is what is needed, rather than a video clip, snapshot tools capture and save an image, which is smaller and easier to share than video. However, snapshots may not represent the entire incident.
  • PTZ Controls: Moving PTZ cameras manually to a target is fundamental for high-security live monitoring. Proper permissions and camera position settings should be made to ensure the camera is not misused (e.g. looking directly at a wall, moved by a second user while monitoring an incident, etc.).
  • Bookmarks: When investigating the video, bookmarking allows for easier sharing of video by tagging a video clip in the VMS which allows searching for the bookmark instead of by time or motion. However, creating bookmarks is fundamental for them to be available for searching.

Video Timeline

Video Timeline allows a user to quickly scrub through a lot of videos ( manually adjusting the current time of being viewed):


However, Video Search tasks are better designed for looking for specific events or a previous day’s footage.

Some VMSes support switching between live and playback video by using the Timeline.

Instant Replay

Security operators can miss important details while monitoring live video, and Instant Replay offers short payback times (15s – 5 mins) while viewing live video, saving the time to open a dedicated video search.


The time limit for rewinding means the incident needed to be viewed live for instant replay to be useful.

Searching Video

Searching for recorded video is a critical feature for a VMS, and offering a fast means to search for a person/vehicle, event, or left-behind object is important for most users.

There are different search types common in many VMSes, each with pros and cons, depending on what information is known. Time, motion, analytics, thumbnail and bookmark searches are the most common types

Time-based Search

Time-based search is the most basic search and is useful if the system does not offer analytics and only a time range is known for an incident:


Time-based searches can take significantly longer than most other search types because you have to scrub through the full-time range of video.

Motion Search

Motion search is generally quicker than time-based search because it shows only motion events on a camera which can decrease the time needed to find a recorded incident.


However, if a motion was not detected by the camera, or if there are many motion events on a camera, motion search can take as much time to review as time-based searches

Analytic Search

Because time and motion searches can take a long time to go through results to find people, vehicles, or objects, analytic searches can greatly increase search speed:


However, classification errors (person vs vehicle, male vs female) can cause poor results. Moreover, in 2020, because it is atypical for VMSes to offer robust analytics capabilities, analytics search offerings will vary widely, depending on the VMS.

Thumbnail Search

Thumbnail searches can be quicker than time or motion searches when an object (vehicle, bag) enters or leaves the view of the camera, and analytics are not offered by the VMS/cameras.


However like time-based searches, video still must be manually searched, and quick events may be missed between 2 thumbnail images.

Bookmark Search

Bookmark search offers quick searching for an event that has been previously identified events:


Exporting Video

When crimes, accidents or problems occur, exporting video from one’s video surveillance system is critical to proving incidents.

There are features common to many VMSes, including export time selection, proprietary video formats, multi-camera export, exported file players, watermarking/encryption support, open file formats support.

Export Time Selection

Setting the correct start and stop time Allowing users to make final adjustments before exporting video, without having to restart the export process makes a VMS easier to use:


However, additional options in the Export menu can confuse non-regular users.

Proprietary Video Formats

Exporting video in the VMS’s proprietary format is quickest and does not require extra processing/time compared to converting to open-formats. Also, analytics and events are included with proprietary video formats, which can be valuable for review:


However, proprietary video can only be reviewed in the VMS client or standalone file player, which can be difficult for 3rd parties (e.g. Police departments, lawyers).

Multi-Camera Export

Rather than having to export video from each camera individually, multi-camera export can save significant time by allowing users to export multiple video files from different cameras simultaneously

While this is more efficient than single-camera export, it can add complexity when reviewing and file management.

Export File Player

Because proprietary video formats require special software for playback, export file players offer playback without installation of a VMS client and VMS-lite features (e.g. zoom, snapshots, fisheye dewarp, events and bookmarks):


These add complexity compared to playing back in open-format players (e.g. Windows Media Player, VLC, QuickTime).

Watermarking / Encryption

Because some end users have to ensure that exported video is not tampered with, watermarking and encryption can be added to the video to ensure it has not been edited or tampered with:


This takes additional time and processing to watermark and/or encrypt video when exporting and when playing back.

Open File Formats

Exporting to open-format video files (e.g. MP4, AVI) means that users can more easily view exported video because they can use common video players (e.g. Windows Media Player, QuickTime, etc):


Advanced features like snapshot, digital zoom, and events/bookmarks are lost when converted to open formats

Camera Setup, Configuration, and Maintenance

Camera setup, configuration, and maintenance are the most common tasks when managing a surveillance system.

There are camera management features common to many VMSes, including discovering and adding cameras, adjusting camera settings, camera health monitoring, firmware management, camera audit reports, and camera replacement tools.

Discovering and Adding Cameras

Camera discovery and adding cameras to a VMS are the first steps to building a system, and should be a quick and semi-automatic process that scans for any cameras online and waiting for a connection:


However, because automatic discovery may not always work depending on the network, manual search and adding tools can be used.

Adjusting Camera Settings

Ensuring correct camera settings (resolution, frame rate, compression) are critical to the proper function of a VMS, based on the system configuration for bandwidth and storage requirements:


However, not all VMSes support adjusting camera settings for all camera manufacturers.

Camera Health Monitoring

Because a VMS is only effective when cameras are connected and recording, camera health monitoring tools perform a critical function. VMSes typically send out alert messages if a camera is offline or not recording, additionally, some offer online/offline health status reports that can be monitored live:


Large VMSes can be difficult to monitor camera health live, while inaccurate false-positive camera offline alerts can lead to support staff ignoring them.

Firmware Management

Updating camera firmware is important because helps keep a VMS cyber-secure and as smart cameras become more common, it ensures that analytics are up-to-date and accurate as possible:


Updating firmware through a VMS is typically limited to same-manufacturer cameras, and often requires using a standalone Camera Configuration Manager from the camera manufacturer.

Camera Replacement Tools

When cameras fail or are updated, being able to easily copy the configuration of settings from the previously installed camera to the new camera is a helpful tool for service technicians/installers:


However, camera replacement is only common in enterprise-focused VMSes.

System Administration

There are many variables beyond the camera configuration when setting up a VMS.

While each VMS offers methods of configuring and rules/limitations for the configuration that will vary significantly depending on the VMS and licensing, there are common categories including storage, recording, scheduling, and user permissions.


Where video is stored and how long it is stored is one of the primary decisions when setting up a VMS. Setting video to recording in the correct server drives, and what percentage of the drive to record to will impact how the VMS will operate.


Because some customers have minimum required days of recording, and others maximum allowed days, proper configuration of how long to record video is a necessity.

Many VMSes support per-camera retention settings, however, this can add complexity to system administration.


Because of the differing needs of customers, selecting the type of recording (e.g. motion, continuous) is important to provide the expected recorded video.


This can significantly impact the amount of storage required. Moreover, different camera settings can be applied for live monitoring and recording for increased efficiency.


Because there can be different priorities for recording depending on the time of day or week, schedules are primarily used for storage optimization. This is less commonly used in 2020 as storage costs have decreased significantly. They can also be used for controlling alarm notifications and user login:


Depending on the complexity of the configuration this can require significant additional setup time of the VMS.

Users – Permissions and Groups

Controlling what cameras users are allowed to see, and when/how they access the system is important. VMSes offer user and user group configuration:


Individual logins (user account per person) provide the highest level of security and user auditing, however, even in 2020, shared logins for monitoring staff, who may share a monitoring PC is still common.

Many VMSes support creating user groups to minimize creating individual permissions for each user, however, this is more common in high user count VMSes.

Mapping Support

Understanding where incidents are happening while live monitoring and understanding the physical relationships between cameras on a VMS is important for security operators, but can be difficult as the number of cameras increases.

There are common map support features including 3 map types, map interaction, and map alerts.

Map Types

There are 3 primary map types:

  • Static Images (2D): Easiest to use and configure, but limited in the features and visual feedback offered in multi-dimensional and Live mapping.
  • Multi-dimensional (3D): It can be easier to track suspects between camera views because it provides stronger visual cues and camera view orientation than static 2D mapping. However, it can be more difficult to configure and can be confusing for non-regular users.
  • Live Geospatial (GIS): Offers a higher level of integration to systems like vehicle location and dispatch commonly found in public safety and high-security operations. It is typically an expensive addon to standard VMS mapping.

Map Interaction

Interactive maps offer better visual cues for VMS events for live monitoring, which allows security users to more easily track suspects or identify suspicious behaviour.

Additionally, with larger high-security systems (e.g. Jails, Airports, Casinos), access control, intrusion, LPR and other systems are commonly integrated into maps for unified system monitoring.


However, very dense interactive maps can create confusion for operators, which will negatively impact live monitoring.

Map Alerts

Visible notifications for alerts and alarms can notify operators when there is an incident, while also showing them where on the map the alert was triggered, decreasing their response time.


However, large maps with many alerts can be more visually distracting and confusing than a basic scrolling alert/alarm list.

Rising Availability of Low-Cost NVRs

A major development in the past 5 years has been the increase in the availability of very low-cost Asian appliances, far less expensive than their Western counterparts.

Western VMS-based appliances are generally 3-5 times more expensive than Asian produced ones. 8 – 32 Channel NVR Appliances from Asia ranges in price from $200 USD to under $1,000 USD, in comparison to Western VMS-based appliances in the $2,000 – $10,000 USD range when fully licensed.

The potential advantages to Western appliances are more native camera driver integrations, developed user interfaces with advanced Video Search and Export functionality, Active Directory support, Multi-Server management, System Health Monitoring, Configuration and User Auditing, GIS Mapping, and Edge Recording.

This chart compares the primary pros/cons:


Appliances Quicker to Setup

Since the software is pre-loaded on appliances, the installing technician avoids installing the Operating System, the recorder application itself, database management software, etc. This can save a few hours and eliminate any errors from installing manually.

Appliances Easier to Deploy

Since appliances can generally start connecting to cameras right after turning them on, it eliminates the need to know how to set up a PC/server and install a recorder/VMS application. For some organizations, this level of knowledge is trivial and poses no advantage, however, for others, this may allow them to do deployments with less skilled technicians.

VMS for Server Manufacturer Flexibility

A disadvantage with appliances, you have to use the manufacturer’s hardware. Two common problems occur here:

  • Your organization has standardized using a certain provider (e.g., Dell, HP, etc.) and you have preferred terms and servicing policies with that organization. An appliance bought from a different provider falls outside that process and may be against the rules or cause logistical issues.
  • You prefer certain hardware specifications or component choices and are not comfortable with selecting the appliance provider. This is generally only an issue for advanced technical users.

In either case, the ability to pick your own hardware is one of the advantages of using a Software Only solution.

Virtualization with VMS

Because Software Only VMS can be installed on any Windows/Linux server platform, many are certified for use in a virtual server environment.

If the hardware infrastructure exists, this will save hardware cost but can add complexity and coordination for installation and support. Installing on a virtual server can require a higher level trained, higher cost technician.

Appliances Simplify Troubleshooting

Since the manufacturer selected the hardware and pre-loaded the software, they have much more control and a better understanding of what might go wrong and how to troubleshoot it. It is much harder for the manufacturer to troubleshoot software loaded on 3rd party hardware as there are many more variables.

It might simply result in more time and more issues but, in the worst case, it can result in finger-pointing and blame being passed that it is your hardware’s issues.

One common concern with purchasing hardware and software separately is that it can result in having two organizations responsible for troubleshooting the surveillance system. The PC/server hardware may fall into one group while the software/application falls to another. This can increase complexity and cause delays in resolving problems compared to an appliance.

Many Appliances Require No Annual Software Costs

Many, but not all software only providers, charge annual costs for maintaining/upgrading their software. These costs can double the upfront license cost over a 5 year period (e.g, pay $150 for a single channel license plus another $100-$150 over the next few years). By contrast, appliance providers typically do not charge annual fees and, often, give away software upgrades.

VMS providers often argue that those annual fees result in much more advanced functionality than appliances do. Sometimes this is true but not always. This point should be carefully considered on the exact platforms one is considering.

VMS Provides More Flexibility to Scale

Appliances typically only are offered in a handful of configurations and often have restrictions on how they can be expanded.

As a general rule, if you exceed the 16/32 channel limit by even 1 or 2 cameras, you will need to add an additional appliance. By contrast, by using a software-only solution, you can switch or add components or machines as you please, as VMS systems generally supporting a much higher camera per server count (128-500).

Of course, this assumes you have the technical skills to do so but for those that do; this can make it easier to scale the surveillance system with more cameras, higher resolution, longer storage, etc.

Many appliance vendors now offer external NAS/SAN storage options to expand overall storage capacity, but those do not add more throughput capacity, just longer retention times.

Appliances Easier for Small System Deployments

The labour cost for setting up VMS software is fairly constant, whether the machine is handling 4 or 64 cameras. It might take 3 hours to set up a machine recording 4 cameras and perhaps 5 for one recording 64 cameras.

However, the cost of system initialization as a percentage of the total job is much higher in the 4 camera deployment. As such, appliances are particularly attractive for sites with small cameras. For instance, even if a user had 1000 cameras but they were split across 250 locations, appliances would provide a significant advantage as it would eliminate the labour of initializing 250 machines.

VMS More Common in Large Systems

Most appliances are targeted at small to midsize camera counts – 4, 9, 16 and 32 cameras being the most common. If you have more cameras at a given site or more demanding requirements (super high resolution and/or frame rates), generally software only is a better option as you can customize the hardware for your more demanding needs.

Widely Used or Notable VMSes and NVRs

Below is an alphabetical list of widely used or notable VMS and NVR manufacturers:

  • Avigilon: Focuses on a tightly integrated VMS / IP camera/video analytics offering, differentiates on the VMS side via their own search and real-time analytics 
  • Axis: The first IP camera manufacturer and still the largest non-China one, Axis offers a variety of VMSes but they are generally less commonly used and marketed.
  • Dahua: A major China camera manufacturer, they also offer NVRs that are widely used due to low-cost but not considered high quality.
  • Exacq: A long-standing VMS, once one of integrator’s favourites, has declined in favorability since Tyco acquired them in 2013.
  • Genetec: One of the earliest VMSes and still independent, Genetec has evolved to be a very high-end provider, whose pricing is uncompetitive in most of the market but whose advanced functionalities are frequently chosen by enterprise end-users.
  • Hanwha: A major and rising camera manufacturer, they offer their own NVR and recently started OEMing Network Optix’s VMS.
  • Hikvision: The world’s largest video surveillance manufacturer, in the West, they are primarily a low-cost camera and NVR manufacturer. Their pricing makes them widely used but their NVRs are viewed unfavourably by integrator’s overall.
  • Milestone: One of the earliest VMSes, Milestone offers a broad range of options, from free to enterprise, they focus on being ‘open’ in terms of 3rd party support and community. They have declined in favorability in the past few years and have split their cloud offering with their sibling company Arcules.
  • Network Optix: A relatively new VMS (founded 2011), they primarily OEM their software to partners (Hanwha, Digital Watchdog). They have risen in favorability as a lower-cost mid-market alternative to Exacq and Milestone.
  • Uniview (aka UNV): The 3rd largest China video surveillance manufacturer, they are gaining in both camera and NVR use in the West, due to bans for Hikua, their NVRs have similar problems to Dahua and Hikvision.