NVR Bit Rate Input Max Specification Question

Serge, in general, such specifications are based across all channels. In your example, that would be 256Mbps across all 32 channels, so as long as the average max bit rate was 8Mbps (i.e., 256 / 32) for 32 cameras, the system should operate.

Some finer details that may be concerned include:

• Accounting for main and secondary streams, i.e., if secondary streams are used, those should be factored in to the calculation, i.e., if the main stream was 8Mbps and the secondary stream was 1Mbps, the total for that camera would be 9Mbps.
• Accounting for both video streaming in and out. Video streaming in to the NVR is straightforward but this specification number may also count video streaming out to clients. How much bandwidth the clients consume depends on the number of simultaneous max clients, how many feeds they are watching at once, whether they use. So if you have 240Mb/s of video streaming in, you may go over if a few clients connect to watch simultaneously because they could add 20Mb/s in throughput out.
• Factoring in peak bandwidth loads. Overwhelmingly video feeds today are variable bit rate and they most often spike when the scene is busy (people in the office on monday morning) or at night (when digital noise increases bandwidth consumption). The average bandwidth might only be 140Mb/s but the peak could be 280Mbs and during those times you could experience video loss, etc.
• Assuming the specification is accurate. The manufacturer could have listed a spec beyond what it actually delivers. Hard to tell without testing the specific model but if you are concerned about hitting the max, worth stress testing first.

Note: If you are you using smart codecs, the chances of hitting these maxes would be really low as their bandwidth savings would be significant.

In general, I would interpret that as a 'whole box' bitrate max.

If the max is 256 Mbps over 32 IP channels, that is ~8 Mbps per channel.

If the max is 160 Mbps over 16 IP channels, that is ~10 Mbps per channel.

That 'max bitrate' then may limit camera resolution or framerates composing the system.  A 720P camera may never approach 10 Mbps, but a 4K camera could easily.

So even though you have 16 channels, you have a hard cap on the bitrate of all those 16 channels.

Who can help me understand the difference between the two in how many cams they can handle and with the bandwidth part.

The 32-ch NVR handles 2x as many cameras as the 16-ch, but at a 20% lower average bit rate per camera.

This made it all very clear, thanks for helping out, I know what to get now... appreciate it thanks!

Hmm I was a bit to quick...

Living on an Island (Aruba) and having limited resources/official suppliers available, the Miami stock supplier only has a few models in stock. I can not wait up to 3 months to get it by ordering items that are currenty out of stock.

When I see these specs:

• Up to 6 Megapixels resolution recording
• HDMI and VGA output at up to 1920×1080P
resolution
• 8/16/32-ch network cameras can be connected with
80M/160M/160M incoming bandwidth
• Up to 4 SATA interfaces
• Plug & Play with up to 16 independent PoE network
interfaces

Does that mean that it can record at high resolution, but will only stream HD to my client?

I use a couple of IP 1080P cams but also some 3MP. Does that mean the full potential of these 3MP cameras can not be used?

Any options or alternatives that I can look out for?

(For example this is the HIK nvr: DS-7716NI-E4/16P)

My other issue: I see some support PoE but a lot don't. How do you power your IP cams if the NVR does not support PoE?

(Thank god I'm starting the networking class in September lol)

Some NVRs list the Input and Output bandwidth as separate specs.

The sub stream is usually for live viewing or live remote view.  In my experience, the sub stream is not counted against the NVR recording throughput, but a separate spec.

The 1920x1080 spec you listed is referring to the HDMI/VGA monitor output, and has nothing to do with the network viewing output.

If you have an NVR that does not have PoE, it is simply an appliance that gets installed.  You then have to provide your own PoE switch, or in some cases, the cameras are powered by low voltage 12v DC/24v AC, depending on the camera and what is supported.

Does that mean that it can record at high resolution, but will only stream HD to my client?

No, it just means that the signal coming out of the HDMI/VGA jacks in the back of the NVR is only 1080p.  It should stream at the recorded resolution.

My other issue: I see some support PoE but a lot don't. How do you power your IP cams if the NVR does not support PoE?

You buy a POE switch separately.  Its usually cheaper overall to get the POE built in to the NVR, but some prefer a separate switch because then it can be easily swapped out in case of POE supply failure.

Living on an Island (Aruba) and having limited resources/official suppliers available...

Surely there is a branch of these guys out there ;)