System Redundancy

In my last post I started the argument that IP video surveillance, in general, has no real advantage over its older brother, analog CCTV systems. Pelco, Bosch, Panasonic, OnSSI, and most others are still using a server centric system, which leads me to the purpose of this post… system redundancy.

With more and more systems integrating with video surveillance and more and more facilities and security managers relying heavily on their video surveillance it is becoming essential to have some fail safes in place to keep the system up in case of failure. One of the critical components of this is the DVR/NVR. Most systems (named above) require the camera to talk the NVR. The video is recorded, analytics (motion recording is an analytic) is performed at the NVR, compression, user access, masking, audio integration, text inserting etc, is all performed at the NVR. But what happens when the NVR fails…? The entire system dies. The cameras cannot be viewed, nothing is being recorded, you’re dead in the water until some tech decides to make some time for you and charge you $250 per hour to replace a $60 power supply.

So, this is where a properly designed and implemented IP based video surveillance system comes into play. There are a couple of systems out there that have complete system redundancy. This is done on several levels and several different ways.

1.       Not server centric – a system that does not rely on the NVR to tell it how to work is the first step to reducing a single point of failure.

2.       Hardware Redundancy – most servers available today have redundant NIC and power supply options. NIC and power supplies are the most common part to fail on a server, other than the hard drive.

3.       Software Redundancy – this is a good feature, some video management systems allow a NVR to fail over to another NVR automatically. When a NVR fails it automatically sends the video feeds to a designated NVR to continue to record with no down time.

4.       Hard Drives – get a server with a video surveillance rated hard drive. Server grade hard drives are designed for heavy read activity, in a video surveillance application there is a whole lot more writing to the hard drive, this is what causes them to fail. There is now, video surveillance rated hard drives designed to have huge amounts of data written to them. Also, have a system with a RAID 5 (or some level of RAID, RAID 5 is preferred) with hot swappable hard drives. This allows for a hard drive to fail without losing the video and you will be able to replace the hard drive without  having to turn the system off.

These are just a couple of ways to build in redundancy into your video surveillance system. Again, a properly designed system is key to providing a system that will be operating when you need it.

CCTV No More!

CCTV, Close Circuit Television. This used to be (and still is) the most widely used descriptive word for video surveillance. Originally, that is what video surveillance was, cameras running to a central location being viewed on special monitors and at times having the video recorded. Then came the PC, video compression and capture cards and we entered the DVR age. Adding audio recording features, digital processing (which is supposed to be better… it’s not), alarm inputs and network connectivity.  Now the DVR age is coming to an end… IP Video Surveillance is all the rage with IP cameras, virtual matrix, megapixel, open platforms, NVRs… etc. Yet we still use CCTV to denote video surveillance. At first I would argue that we need to change how we describe video surveillance, however, if one were to take a hard look, beyond the flashy advertisements, glossy brochures, and the sales reps pitch, one will find that the truth is, it is still CCTV. It just now costs more… follow my thoughts if you dare.

Traditional CCTV systems connected first with a camera -> to a coax cable -> to either a multiplexer or matrix switch -> to a DVR or VHS for recording. The feed from the multiplexer and matrix switch goes than to the monitors. The only way to access the system, view the cameras or manage the video is by sitting at the DVR. The system is closed.

Now, we are in the technology age, IP Video Surveillance. We now have an IP camera -> to a CAT5  cable -> network switch -> to a NVR. Tell me, what is the difference from this and the system above? All we have done is change the mode of transmission from Analog to IP, from coax to CAT5 and instead of a DVR we now use a NVR (it is the same thing!). We now charge for software upgrades, licensing fees, and only have a small handful of cameras that can integrate with any given software package.

Yes, there is network connectivity, but that is performed the exact same way on both systems. The CCTV system is connected to the network, when a user wants to access the system, they log into it like they would log into a server on their network. Between Analog and IP CCTV systems there is no difference. I ask you, how is this different? What advantages are there to go to IP and yet continue to use this topology?

I like IP Video Surveillance, there are true advantages to it. But there are only a small handful of manufactures that are get it. So over the next couple of weeks I will attempt to describe what a TRUE IP, Video Surveillance system should look like.

-          System Redundancy

-          Distributed Topologies

-          Large Enterprise Deployments

-          Video Analytics

-          True Scalability

-          Service and support