Physical Security Thread, IP CCTV Cameras in Technical; Hello,
This year we want to look at scrapping all our current analogue CCTV (most of which doesnt work anyway) ...
12th January 2013, 02:45 PM #1
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IP CCTV Cameras
This year we want to look at scrapping all our current analogue CCTV (most of which doesnt work anyway) and are looking at AXIS internal and external IP POE HD cameras.
My only concern is that if we were to install over 30 of these cameras to be recorded by a server (with CCTV capturing software on it)
A) can one server cope with this and the bandwidth of all cameras
B) would this amount of cameras with a constant video stream slow down the rest of the network (we are a large secondary school site with over 500 machines)
I would be really interested in hearing about others experiences and your best practice thoughts and concerns.
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12th January 2013, 05:49 PM #2
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As long as the server is reasonably well powered, recording 30 cameras should be no issue. I've seen one school that was recording well over 80+ IP HD cameras to a single Dell PowerEdge server. Their server had 2 CPUs and 15k SAS hard drives, both of which should help with the performance of the system as the number of cameras increase.
How fast is your network backbone? If it is 1GB or 10GB, I would not think 30 cameras would slow it down significantly. If it is 100MB, I would recommend upgrading that before attempting the camera upgrades. For both performance and security reasons, I would also recommend using a separate VLAN for the cameras. The DVR server that would capture all the video could then be placed on both your CCTV VLAN and your data VLANs as long as it has two network ports (if you place it just on the CCTV VLAN, there would be no way for SMT to view the footage over the network, which would probably be an issue). Alternatively, if you wanted to be even more secure, you could build an entirely separate physical network for just the cameras (separate switches and wiring that would be used just for the cameras). This would also eliminate any potential performance issues.
I would recommend using POE for all cameras, both internal and external as this allows you to keep everything powered up during power outages by just putting your switches and the DVR server on a UPS. Otherwise, getting each camera on a battery backup becomes more complex and expensive. The other advantage of POE is that if a camera locks up or has a strange issue, you can simply login to the network switch and cycle power for that specific POE port (much and easier faster than having to get on a ladder at the camera itself to restart it).
For the exterior cameras especially, check on the light requirements to make sure they would be usable after dark. If you have good external lighting, this would not be much of an issue though.
Hope this helps.
12th January 2013, 06:55 PM #3
We converted all our old cameras from coax to ip and built a server using blue iris, Beauty being you can add network ip cams and even usb easily enough. our server runs 8 cameras and maxed out a dual core processor but is fine on a quad core. You could set up server smaller servers and have then archive them to an a share after a day or so.
12th January 2013, 09:23 PM #4
I've got 18 HD CCTV cameras hanging off 4x7200rpm hard drives in RAID5 recording on motion only and haven't noticed any performance issues.
The biggest thing I've seen is in the CPU usage - out of a 3.2ghz AMD Phenom II quad core CPU its using about half the CPU to do the encoding - will probably upgrade to one of the newer AM3+ CPUs later on if ever needed.
One word of advice - you may find it hard to justify keeping CCTV footage longer than a few months so you won't need high capacity hard drives but with a high number of cameras you might need faster HDDs (than just 7,200rpm).
12th January 2013, 10:27 PM #5
Every system is different and your requirements will dictate your hardware and network needs.
We have 90 Cameras and 6 DVRs
Motion Triggered Recording is what eats CPU's, disk space and bandwidth regardless of it being IP or not.
Obviously the higher resolutions will only push the requirements up.
VLans on their own will not help you much apart from separating the traffic, when you reach an uplink it still has to squeeze through alongside your normal traffic so link aggregation is essential if you want to avoid bottlenecks.
Personally I prefer to keep the CCTV off the data LAN where possible.
Also spare thought for where the repository is located on the LAN as searching and retrieving stuff from DVR arrays is also a CPU killer and bandwidth hog when you want to recover/save a recorded story.
I published some network stats in another thread of some real world cctv bandwidth - see if I can find it.
720p motion recording is about 20Mbps per stream @ 20fps
So 30 Cameras all recording an active motion stream is 600Mbps which will have a significant impact on a gigabit uplink.
In schools this might not be a big deal as the busiest CCTV time is as kids move around between lessons and this is when they are not using the pc's. Drop the frame rates and carefully set your triggers to limit the bandwidth.
Mine run at around 90% load for about 3 hrs, 22 times a year and for this we have a dedicated circuit.
Try this as a guide. Bandwidth and Storage Calculator | StarDot
13th January 2013, 07:45 PM #6
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@m25man - Thank you very much for your extensive answer. Its a real help and strengthens my case for perhaps a separate network purely for CCTV and in the short future IP Telephones too.
16th January 2013, 02:43 PM #7
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I just read your post and thought that you may be interested to get some feedback from someone who does this on a regular basis.
Firstly, one server can certainly handle 30 HD IP cameras (within reason) the H.264 compression techniques used in most modern IP cameras mean that the average bandwidth from a single HD camera streaming 25 frames per second can be as little as 5-8 mbps (without any additional compression). In reality it is fairly standard practice to stream an HD camera at around 5fps which is about 1mbps so you certainly shouldn't have any issues with bottlenecks.
The only server consideration here is that whilst H.264 is efficient at delivering low bandwidth images, due to the way it works it is quite processor heavy and many IP software platforms will require your server to have at least an I5 processor or quad core processor as a minimum (based on 30 cameras). It would also be wise to look at Windows 7 pro and as much RAM as you've got.
Whilst that takes care of the traffic to the server there is also the matter of live viewing from selected viewing stations that needs to be taken into consideration and therefore it is advisable to ensure that you instruct your installer (or do this yourself) to restrict the live feed from the cameras to 5fps, if your camera allows this (which most do) and restrict the ability to live view to just a few key personnel. Again the software platforms can usually restrict the access in the manager/server programmes.
If the bandwidth is still a concern then it is not normally a huge undertaking to install a completely separate network for the CCTV. Any installer who knows enough about IP systems will be able to advise you on this and would normally install separate POE switches with 1GB uplinks and leave spare ports for any future IP systems such as access control or telephony.
If you have any further questions feel free to let me know and I will be happy to advise.
16th January 2013, 06:34 PM #8
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Thanks @Sunstone / Paul, that information is great.
We are literally going to start again with new internal / external cameras so is a server the best way to record the footage of get networked DVRs? The feeds will need to be viewed constantly on screens in our Site Management Office and Facilities Management Office plus us in Network Management if we need to look up any incidents.
I think a seperate network will be a must and POE is an absolute yes... can you recommend a good model of camera?
And it sounds like you have a lot of knowledge and perhaps carry out installations yourself so message me your details if you want.
17th January 2013, 10:18 PM #9
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In my opinion I would certainly say that a server is the best way to record the footage on site. You may hear the term NVR banded about but in almost all cases this is just a standard windows server (occasionally linux) but specified and built by the manufacturer (at a premium naturally) and not all NVR’s accept all cameras so I believe it is safer to opt for a server and an IP software package such as Milestone, Exacq or Mirasys to name a few of the more popular ones, as these will give you a lot more options now and in the future.
There is so much choice on the IP camera front at the moment and to confuse matters further it is not always a case of you get what you pay for. You will probably hear the more common names such as Axis, Sony and Panasonic but Axis are probably the most popular. It is worth bearing in mind that the better Axis cameras do tend to be a bit expensive and in terms of image quality there are actually better cameras for the money. The cheaper axis cameras do tend to perform quite poorly in low light compared to some of the other brands but for internal general use they are pretty good and very reliable and usually come with a good warranty. For external cameras this is more tricky as many cameras suffer from motion blur in dark conditions. There are a few better ones which come in either a vandal dome or bullet style housing with in-built IR lights which are superb up to about 25m and are still POE. We have had great success at a school in North London with these and the customer has been extremely pleased. But on this site we have actually recommended three different manufacturers because every shot has been different and we specified the camera that we knew would suit the environment.
As with all things there are options to suit all budgets and if you were going to try and do it all in house then I would say opting for something like Axis on any of the above platforms would probably be the cheapest and easiest overall.
If you are looking to go down the route of getting an external company in to manage the project and look after the equipment then the added benefit here is that a separate network with any performance issues would be their problem.
After reading a few of the posts above again I think it is worth re-emphasising the issue of processor power as it is important. It is true that lack of processing power is usually the biggest cause of performance issues in our experience. We have a system that is currently running 16 x 1080p (2mp cameras) at 5fps constant recording, 3 x 8mp cameras @ 16 fps each on motion detection and a 5mp external dome at 5fps on motion. We have a server running 2 x Intel Xeon E5-2609 processors, 16GB RAM and RAID5 storage with 12TB available.
Current stats are 24 days storage, even with constant recording on 16 of the cameras and the CPU usage never goes above 30% even at the busiest times. The installed system was designed to take 40 cameras on similar settings and we have 3 spare drive bays for further expansion if needed. We will be moving everything over to motion record in due course. There is a separate network installed and the viewing stations have all had I7 processors installed and the whole system runs like greased lightning. This was overspecced in my opinion but it is what they wanted.
Bandwidth is a concern in certain circumstances but you would struggle to hit anywhere near 600mbps from 30 HD cameras on h.264. 30 x 2mp cameras on 25fps live streaming would be at most around 250mbps to 280mbps. So you can start to see how reducing frame rates to 5fps suddenly makes viewing several streams live at viewing stations less of an issue than it used to be. 30 cameras on 5 fps drops the bandwidth to around 60mbps when viewing live and as long as you have a 1 GB uplink at the key points you shouldn’t experience any issues.
Hope that helps but again if you have any questions feel free to touch base.
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