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Need Help Specifying Recorders For 176 Camera Project

i need an expert advise.


Area/Location type: Government (Public Service)

At least 60 days video retention with all cameras at 12 fps (is 12 fps makes sense?)

No. of cameras : 176 (i need allowance for up to 200 cameras for future expansion)


1.With this number of cameras and days of retention, which is more pratical to use( in terms of budget and ease of use), NVR appliances or COTS server?

2. What are the things i need to know? (i dont know how to compute bandwidth)

3. how many COTS server / NVR i need? (or how many camera per server?)

3. Can you help in me with the specifications that i must include for COTS server or NVR applicances

4. Amount of Storage? Is SAN needed?

5. how many workstation i need?

Thanks in advance.

End user here.

CAMERA Resolution Camera Type Day&Night Functionality / with IR Day&Night Functionality / with IR / with WDR Total
1.3 Megapixel PTZ 8 138
Fixed Dome 126 4
2.0 Megapixel Fixed Dome 24 4 28
3.0 Megapixel Fixed Dome 4 10
Bullet type 6

Thanks for asking.

I am going to make some assumptions in my response and will list them when relevant. Please let us know if they are incorrect.

Assumption: The cameras are in the same building and/or can be streamed back to a single location.

Question #1 Answer: NVR appliances are easier to use, to the extent that software and storage are preloaded. However, COTS servers allow you to scale to higher camera counts and be more flexible in how and where you store video.

Important, how much cost and flexibility tradeoff exists depends on what NVR / VMS manufacturer you are selecting. Do you have a short list of companies you are considering?

Question #2 Answer: Computing bandwidth depends on many factors including the resolution and frame rate (which you've provided). However, it also depends on compression level, the scene complexity (i.e., is the camera watching an empty hallway or a busy intersection) and differences in how cameras handle video.

The best way to compute bandwidth is to get a model of each camera you plan to use and measure it at your site.

For more, How to Calculate Surveillance Storage / Bandwidth

Question #3 Answer: 64 cameras per COTS server is a common specification. However, how many cameras a server can handle depends on the server specified and what you are doing.

Do you plan to do motion detection on the server side or plan to run any analytics on the server? Either of these will significantly increase demands on the servers and could reduce your camera count.

For more, see Specifying VMS Server Size.

Question #3 Part 2 Answer: For specifications to include for COTS server, I am assuming you mean hardware specs, like CPU, RAM, NIC, etc.

This is something you should ask the VMS / NVR manufacturer after you pick them as it can vary depending on manufacturer.

Assumption: I am assuming you are going to record continuously. If you record on motion only, storage will be reduced typically between 30% and 70%.

Question #4 Answer: How much storage needed depends on bandwidth consumed. For a 1.3MP, 12fps, bandwidth can easily range from 300Kb/s to 6Mb/s (assuming H.264, default compression). That's a huge range. Again, as mentioned above it depends on scene complexity and how the camera handles video compression. See: Advanced Camera Bandwidth Test Results

To get a ballpark, let's say your average camera consumes 2Mb/s, and records continuously for 60 days. That would be ~300 TB.

As for getting a SAN, I think network based storage would provide greater flexibility and expansion, especially since that's a fair amount of storage (100+ hard drives will be needed).

Question #5: What do you mean by workstations? Do you mean PCs for operators to view video?

Thank you sir for quick response. Yes. All cameras are in the same building, 8 storey building, cctv room is at the first floor.. Since we are in government we cannot simply select a specific brand/manufacturer/systems integrator. This project will undergo public bidding. I received quotations from different S.I. that recommend the following brands: Axis, Bosch, Avigilon, American Dynamics, Acti, etc. Yes. Workstation for operator. Can i get your personal email so that i can send you my draft T.O.R.? I need to know if the details in my technical specifcation are correct and appropriate. Thanks

I just emailed you. My email, just in case, is

Given that you are doing a public bid, the key thing is specifying in enough detail to close loopholes / ambiguities in the responses.

Btw, our IP Camera Specification Guide may help you as well.

What is the common throughput of a COTS Server?

It depends on the specs of the machine.

From our Specifying VMS Server Size report:

VMS server performance is most dependent on CPU and RAM, directly impacting how much video may be recorded. Exact requirements vary depending on the specific VMS used, but some general trends can be found by looking at manufacturer specs:

  • Small systems, ~1-10 cameras: Single or dual core processor, such as Intel's Atom or Core i3, 1-2 GB RAM.
  • Mid-size systems, ~10-40 cameras: Dual core or quad core processor, e.g., Core i5 and i7, 4-8 GB RAM.
  • Large systems, ~40+ cameras: Quad core processor or higher, such as Xeon, 8-16 GB RAM.

A lot of what you ask are generally good to know, but the obligation to fulfuill requirements should really fall on the S.I. If you tell them you need 60 days of video retention, then it should be their responsibility to quote enough resources to fulfill 60 days of video retention, and not something you should have to worry about to much. However, you will probably want your IT manager involved to overlook their proposals to make sure they are being realistic. Don't let the IT manager spec the equipment, or they will mess it up by saying something like "It should all be Dell equipment, or Cisco equipment, or DLink cameras..." or something like that.

Like John said, compression and motion activated recordings can greatly affect how much video is retained, so be wary of those tricks. If you leave an SI too much room and ambiguity, you'll enable them to low ball you a really low price because of less storage needed, while they put in the fine print "we expected on 10% motion at any given time", which unfairly gives them an advantage over other SI's bidding beause they were allowed too much unrealistic leeway.

The bid should specify how much video retention you want, with whatever minimum level of quality compression you're willing to accept (another way an SI can unfairly get ahead), and if not based on continuous recording, then specify what percentage of motion detection everyone needs to uniformally figure into their calculations.

As to the number of servers, throughput, etc, that really should be for the SI to worry about. If they are using a VMS system that requires double the amount of servers another VMS requires for the same number of cameras, then that's their problem, not yours.

Why on earth are you attempting to specify a complex system of this size yourself? You really should consider bringing in an experienced security consulting engineer to evaluate the project requirements and prepare bid documents and specifications. IPVM has documented many cases where government agencies have attempted to design and spec their own systems and it ended badly.

.... and that I would strongly second.

Unfortunately, i am the one assigned to create the technical specifications. Is there any articles here regarding PoE switches and core switches?

No offense meant and with all due respect, if you are asking these types of questions in an open internet forum you are most likely not prepared to produce tech specs for an ITB/RFP for a government project of this magnitude.

My best advice, hire an experienced security consulting engineer to prepare the technical requirements. If you don't have the budget for that now, you will end up paying for it with a poor quality system or a pile of change orders later.

No, I am not a consulting engineer looking for business. I'm an integrator, an honest one with experience in municipal systems. I've seen this scenario play out too many times before. When a municipality writes the specs for a totally new system installation, it rarely ends well. The dishonest firms and/or lowball trunkslammers are going to lick their chops at an opportunity like this and the experienced integrators you want to respond usually won't waste their time preparing a bid. Caveat Emptor.

Unfortunately, i am the one assigned to create the technical specifications. Is there any articles here regarding PoE switches and core switches?
Hi sir John What do you think about the details in my technical specs ?

I sent you feedback on the camera part last night. I am busy this morning but will try to send more later on the VMS side.

As others have suggested, this is a big enough project that you should hire your own local security consultant.


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