NVR, DVR, or Video Server?

By Virginia Fair

“Questions………we get questions”

Wasn't that a jingle on a popular TV show of the Sixties? (Seventies?)  Well it could be Kintronics' theme song, too. Our sales engineers get all kinds of questions when fielding calls.

 Today we’ll give you a hypothetical conversation that could occur any day. A caller wants to know what type of video storage device her business should use.

Caller: “What is the difference between a Video Server, a NVR, and a DVR?”

Video Server

Sales Engineer: The network video server is a computer that runs special Video Management Software known as VMS and is used to record video from IP cameras. A windows computer is usually the platform for the VMS, and video is recorded onto the computer’s hard drives in a special video format.

Sometimes people are confused by this term because a number of years back a device that attached an analog camera to the networks was also called a video or camera server. Now that’s known as a Video Encoder.

Caller:  Yes, I was confused by that myself. Now what about the NVR?

NVR

Engineer:  A NetworkVideo Recorder, or NVR, is a complete IP camera recording device. It includes a computer and special Video Management Software. VMS is required for recording video, but it also allows multiple viewers to monitor real time and recorded video.

Caller: I think I understand, but could you go over the differences between the Network Video Server and a Network Video Recorder one more time?

Engineer: Sure. The Video Server and Network Video Recorder are similar in that they both record video. The Network Video Recorder comes with the Video Management Software already installed.

 The Video Server does not include VMS. You select the software you like and load it.

The Video Server usually runs on a Windows operating system and it’s more flexible than the NVR because it is easier to expand and add cameras. The NVR, on the other hand usually has a fixed limit as to the number of cameras it can support.

Caller:  Okay, Got it. Now what about a DVR?

DVR

Engineer: The DVR or Digital Video Recorder is a device that records video from analog cameras to one or more hard drives. The term DVR is also used by the consumer TV market.

 The DVR used in the security market has a fixed number of BNC connections to attach cameras. DVRs are available with 4, 8, 16, 32, and 64 channels, or connections. This means that you have a maximum number of cameras that can be supported by one unit. Once you exceed the number of connections available on that particular DVR, you will need to add another DVR to your system.

 There are some DVRs that can connect to the network, and be viewed using a Windows computer.

Caller: Uh-huh, so what’s difference between a DVR and a NVR?

Engineer: There are several differences but let’s start with these:

• The NVR connects to the computer network along with the IP cameras. So you can take advantage of the existing network infrastructure, meaning you don’t have to run wire from a home base location.
• The DVR uses coaxial connections to each of the analog cameras.
• The NVR supports high resolution megapixel cameras
• The DVR supports only cameras with VGA resolution

Caller: Do they all let me store pictures on my hard disk for later viewing?

Engineer: Always with a NVR, and with the Video Server and DVR, as long as you’re using VMS.  Also, if you’re using VMS on your Windows compute, you can usually distribute the storage across a number of different hard drives on your network. It depends on the VMS.

But no matter which VMS you use, storing images every second, around the clock means storing a lot of pictures that are exactly the same. So you’re using valuable space to no avail. One way around that is to have a motion detector starting and stopping the recording. Another space-saving alternative is to reduce your frame rate.

Caller:  Okay, let’s talk about this software. What do I need?

Engineer:  There are a number of VMS products out there. The main job of any Video Management Software is to record the video from many IP cameras on the network. It is very important to select software that’s reliable and doesn’t crash. Imagine how you’d feel if you lost important video. It’s also important to use a dedicated computer system to run the software.

The various VMS products available have many additional functions, including motion detection, sending special alerts to tell you if something important has happened, flexible displays of real time and recorded video, easy location and display of multiple recorded video channels. The features you choose depend on your particular objectives.

Caller: Do I need a network switch?

Engineer:  Yes. You may have to add a network switch if you don’t have any empty ports on your current switch, or if you don’t have a network switch installed. You require one port for each camera.  It’s best to use a network switch that includes PoE on all ports.

Caller: PoE? What’s that?

Power Over Internet (PoE)

Engineer:  The latest IP cameras get power over the network. This is known as Power over Ethernet or PoE. You can also add a PoE midspan, or a power injector between the switch and the camera.

Using PoE means you only need to run one network cable to each camera. That makes installation so much easier.

Caller: How about a video switch? Will I need that?

Engineer: No. The LAN network switch operates as the switch allowing hundreds of cameras to be viewed on a network.

Caller: Wow, Let me run this past my boss and I’ll get back to you as soon as we figure out which will serve us best.

Engineer: Would it help if I send you some specification pages and data sheets to help with your decision?

Caller. That would be great. Thanks so much for all the information?

Do you have any questions? Do you need clarification for any of the answers here? If so, our sales engineers can provide you with all the answers you need. They can also help you with IP cameras, Door access control, and IP paging systems. Call us at 914-431-1658 or fill out a request information form at http://www.kintronics.com/RequestInfo.htm

Virginia can be reached at virginia@kintronics.com

Video Recording for IP Cameras

The Changing Technology of Video Recording
Pros and Cons of the latest IP Camera Recording systems
by Bob Mesnik

Recording video from surveillance cameras has changed over the years. First there were Video Cassette Recorders (VCR’s) and then Digital Video Recorders (DVRs) and now there are Network Video Recorders (NVR). VCRs were around for many years and have been replaced by DVRs that use hard drives. Now, NVRs that support the latest network attached IP cameras, are starting to replace the DVR. This article reviews the technology and how it has evolved over the last few years.

Video Recorder
Early video tape recorders were introduced in the 1950’s. In the 1960’s Sony introduced the first videocassette units (U-matic) which lead to the Beta and VHS VCR products. In the 1970’s the VCR started to be used in the surveillance market.

Video Cassette Recorders (VCRs) used in surveillance, are modified consumer VCRs that have one or more camera inputs to record video from CCTV analog cameras. Duration of storage is usually only up to ten days, depending on resolution and frame rate. These systems were simple to use and relatively inexpensive. Prices ranged from $200 to $1,000.

The downside was the difficulty in finding a specific videotape and then a specific time period. Tape is not too reliable, so even if you find the right tape you may find the video has deteriorated.

Digital Video Recorder
Around 2000, the DVR was introduced for surveillance applications. The Digital Video Recorder (DVR) converts analog video (from CCTV cameras) to digital data and records the data on computer type hard drives. 4 to 16 analog cameras can be attached to a DVR. These systems provide far more storage than tape, are more reliable and provide almost instant access to the stored video. Prices range from $500 to over $2500 (for up to 16 cameras).

Since the video is stored in a form that’s more compatible with computers, the video can be processed and distributed easily. DVR systems incorporate better video compression, and provide motion detection and alarms. Many DVRs have network connections. Data can be sent over the network and viewed on a PC or it can be stored on CD or DVD-Recordable discs.

The upside is the ability to attach a variety of analog cameras into the network. The downside is that the DVR system has a fixed amount of storage and is not easily expanded.

Network Video Recorders (NVRs)
The NVR or IP software is a major advance over the VCR and DVR. The introduction of network attached IP cameras around 1996 required a new type of recording system to be developed. Instead of using coax cable to distribute the video, the video is digitized and compressed in the camera and attached directly to the Ethernet network. The digitized video is now distributed over the network just like any other computer data. A number of software and hardware products were developed to support these new IP cameras. The software runs on standard computers connected to the same Ethernet network as the IP cameras. The software transformed the standard computer into a Network Video Recorder. Now many hundreds of IP cameras can be supported by this IP NVR software. Prices range from $500 to well over $25,000 (for hundreds of cameras).

Some manufacturers also introduced NVR systems that included a computer. The purpose of this system was to make the transition from analog CCTV technology to the new network attached IP technology as easy as possible for the video dealers. For example, instead of using a 16-channel DVR you could now get a 16-channel NVR.

The NVR systems are much more flexible and expandable than DVR systems. The Ethernet network can support a very large number of IP Cameras and the more advanced NVR software is designed to use multiple computers to support an almost unlimited number of cameras.

Most NVR software runs on a Windows type PC system. An IP camera system consists of the IP cameras, computer with hard drives and IP or NVR software. The computer performance and hard drive capacity depends on the number of cameras, the resolution of the video, the frame rate of the cameras as well as how long you want to store the video.

NVR software can be scaled to the requirements of the surveillance system. You can get low cost camera systems that support up to 25 cameras, medium level solutions that support up to 64 cameras and enterprise solutions that support hundreds of cameras.

Software Overview:
There are a number of software options such as NUUO, ProSightSMB, NetDVR and NetDVMS from OnSSI and a number of versions from Milestone (which are similar to the OnSSI software).

The software uses your own computer and it will allow you to view, store and retrieve video and control the cameras. There are a number of common capabilities and each package also has some unique features and functions. For example, all versions allow you to view the video using a web browser from anywhere on the Internet, store video only when motion is detected, and notify you of motion alarm by email or by an alarm sound on the PC. NetDVR and NetDVMS are more robust server/client type software and add among other things the ability to patrol through preset PTZ positions and to transfer the video to alternative storage on the network.

The software is licensed according to the number of cameras you are supporting. ProSightSMB and NetDVR are both licensed by groups of cameras 4, 9, 16 25, 36 64 cameras while NetDVMS is licensed with a base license plus a per camera license. Here are examples of each type of software license:

NUUO is an entry level software for small numbers of cameras. It runs as an application (rather than a service) so should be used with care in commercial surveillance applications. It is licensed for 4, 8, 12 and 16 cameras.

The following software solutions from OnSSI can run either as an application or a Service.

ProsightSMB is entry level software that supports a maximum of 25 cameras. It is a single site and single server type product. This is a small-scale video management system that provides live video, recording, playback and camera management and control. It allows viewing of cameras from any computer using a web browser.

NetDVR is a mid-range product that supports up to 64 cameras on one server, and operates as a server/client. It includes features such as NetGuard client software for viewing up to 64 cameras at a time on any workstation on the network, auto-patrol mode for PTZ cameras, stores audio and allows video to be off-loaded to additional storage on the network. It includes NetMatrix that pops video up on any designated PC monitor whenever there is an alarm condition.

NetDVMS is an Enterprise product that supports hundreds of cameras. It is licensed with a base license plus a per camera license. Besides having all the features of NetDVR, this software can run on multiple servers that are distributed over many sites. It includes NetMatrix that pops video up on any designated PC monitor whenever there is an alarm condition, and Net-PDA software that allows a user to view and control cameras from their PDA.

Advanced content analytic software can be added that counts people in an area or detects if a package has been left unattended at an airport. The bottom line is that more protection can be provided by these complex systems using much less human resources.

If you would like more information please contact us at 1-800-431-1658 or 914-944-3425 or send a message.