Wednesday, May 14, 2008

Value of Stored Video

How precious is your stored video? Not very? Quite a lot? Very important, mission critical or drop dead important? These are the kinds of vague answers we hear that reflect your attitude toward risk. And that attitude drives the dollar value you are willing to invest to avoid losing the video you have gone to great lengths to capture and archive away for that rare incident review moment when it magically becomes more than just video - momentarily it becomes unimaginably precious.

This question is much harder to answer than it first seems, and understanding your options will help you make the right investment that suits your needs.

Hard drives follow Moore's Law - doubling in capacity or halving in price every 18m or so. This means that the 120GB hard drives of 3 years ago were tiny compared to the 750 GB and 1TB that are available now with 2TB drives around the corner. This technological driver has one major impact. Five years ago some customers could only afford low quality video which had lower resolution and frame rates. Now, customers are recording video for longer, a month instead of a week, 3 months instead of 1. Some customers, often regulated, store their video for a year, 3 years or even 5.

DVRs invariably have storage inside the box and you can easily buy DVRs with 2-3TB inside the box. If these hard drives are not configured with redundancy then if a hard drive fails you lose your video. It's not for me to say if this is acceptable or not because it depends on your situation. However, 3TB is a lot of video to lose by anyone's standards. Also, if a drive fails, typically it is not field replaceable and so you have to send the entire unit back for repair, including your sensitive video. At this point you can no longer control who watches the video and you have to rely on service professionalism and good faith.

An option is to configure the hard drives as a RAID - Redundant Array of Independent Disks, which immediately improves reliability because it can survive one drive failing. There are subtle differences between the most common RAID levels in CCTV, RAID, 4, 5 and 6, but the most common is RAID 5 and they all provide protection in case of a disk failure. If a drive fails, you don't even power down the machine - you just eject the faulty drive and insert a new one. After a few hours of the disk array rebuilding itself you are back to normal.

Currently DVRs rarely support RAID inside the box - it is far more common to attach an external disk array to a DVR (using a SCSI cable), and barely use the DVR's internal HDD. These off-the-shelf disk arrays are always more expensive, and noisy, than internal hard drives, but they are more reliable - and you can choose from many different manufacturers with subtly varying features. To achieve economies of scale you can sometimes share one disk array between 2 or even 4 DVRs - assuming the DVRs are co-located and all within a couple of feet from the disk array. Such disk arrays come in different sizes ranging from 2TB to over 10TB.

Disk arrays are often associated with centralized storage, which is why it is the default storage type for IP video where dozens or hundreds of IP cameras' or IP encoders' streams find their way across an IP network to reach an NVR server, and land safely on the directly-attached SCSI disk array. The alternative design is to use iSCSI disk arrays, and stream those same IP cameras and encoders directly to the disk array without going through an NVR - Bosch refers to this as Direct-to-iSCSI and it combines all the reliability and scalability benefits of a RAID disk array, whilst eliminating the need for NVRs, which are expensive bottleneck PCs running operating systems and anti-virus software.

But even with IP video, some people don't use RAID. For example some people use encoders with a small hard drive embedded in the encoder, or a direct-attached USB hard drive, or a removable CF card. Others are using tiny memory cards embedded inside the IP camera itself. These are reminiscent of the concept of a DVR and are completely viable solutions for specific IP video applications, and Bosch refers to this as Recording at the Edge, because the video does not have to traverse the network to get recorded.

I'm not suggesting that everyone buy RAID storage, after all Bosch sells both DVRs with embedded HDDs as well as RAID disk arrays, and as with all things one is not outright better than the other, but for a given situation one is likely to be more appropriate than the other. But I did want to share some of my thoughts, especially with those that could benefit from its value but aren't sure about taking the next step.

Friday, May 9, 2008

Cost Cutting with IP Communications for Fire/Intrusion

For the past few months, we've focused on IP video topics, but it's time to switch gears a bit - since this blog is dedicated to all IP security-related topics - and recognize some of the benefits of using IP with intrusion and fire systems.

Likely one of the most important benefits for the end user is the ability to reduce operating costs by using IP for communications between control panels and the central monitoring station and eliminating the dedicated phone lines previously used for these communications.

Davidson College in North Carolina provides an excellent example of this. The college's IT staff recently challenged their integrator to engineer a way to shift the primary monitoring infrastructure to the campus fiber network. The integrator recommended using IP communications modules, so the college could continue to use their existing fire and intrusion control panels, while communicating to the central monitoring station over the Internet.

At Davidson, 70 fire systems from a variety of manufacturers protect the residence hall, classroom and administrative buildings throughout campus. All of these systems now communicate to the central station using IP as the primary communication method. If the network fails, phone lines connecting the panels to the college’s PBX switch serve as the back up.

Previously, two phone lines connected each panel to the PSTN for communications, requiring 140 dedicated phone lines. By eliminating the direct connections to the PSTN for each panel, the system's operations costs have reduced significantly. Davidson's IT project manager reports that the college has already experienced a 50% cost savings, and he expects that number to increase to 75% in the near future.

For many customers, cost savings is just one of the benefits of IP communications for fire and intrusion systems, albeit an important one. We'll explore some of the additional benefits in future posts.

Friday, May 2, 2008

Tangled in technology

Something happened to me at ISC that I wanted to share. I met a really smart guy, who was indirectly connected with a fascinating technology sector - they make tiny converters that allow IP devices to reuse an existing coax cable infrastructure. As one of the global players that will drive his business he wanted to know my opinion on the future of this segment as the ratio of IP to analog cameras, though still a minority, continues to rapidly increase.

He argued that you could switch from analog cameras to IP cameras without recabling, just by adding pairs of these devices in a point to point manner and then have the head-end of the cable go into a regular network switch. And the cable reach is impressive too.

I was suitably impressed and I can see niche applications, however he seemed disappointed by my general lack of enthusiasm for the possibility that this was the silver bullet that was going to accelerate wide-spread IP video adoption. I asked him under what circumstances would an end user climb up a ladder, or maybe even rent a cherry picker truck, dismantle a camera housing, disconnect and remove the perfectly functioning analog camera and throw it in the trash can, install an IP camera at more than twice the cost, connect it via 6" of CAT-5 to his fascinating connector, which in turn gets connected to the existing coax, power up the new camera (but without the benefit of power over ethernet), realign and refocus (sometimes by holding a cross-over cabled laptop in one hand while adjusting the camera while standing on the ladder). All so that you can view the same image you had in the first place! Except of course NTSC IP cameras can never look as good as analog cameras because they modify the image, introducing artifacts. So in fact the picture looks worse than when you started. And of course, you would have to repeat this for each and every camera.

Of course now we can dual stream, record on NVRs (or Direct-to-iSCSI), run embedded analytics and view the video from the other side of the world -- all the benefits of IP video. But in this common scenario couldn't we have just walked into a closet and simply installed a multi-channel encoder where the old coax cables terminated anyway, and get the identical end result?

I see the converters as offering a great solution if you are going to install Megapixel cameras, or if you want to combine multi-channel encoders from various closets. But it is rare to find a closet nowadays that does not house a network switch anyway so again, what is the high-volume application for today?

Is this a classic example of technology for technology's sake? An engineering dream that invents something without an understanding of what the market really needs? And if so, how common is this among manufacturers today? Remember that today the volume of Megapixel cameras is dwarfed by CCTV IP cameras, in turn dwarfed by analog. That is the story as of ISC West 2008 anyway.