Better performance when DVR has direct camera (RJ45) ports?

[sumguy]

Correct me if I'm wrong, but with the Dahau 4-camera (and maybe also the 8-camera) DVR's only seem to have dedicated RJ45 ports for each camera if the DVR is a POE model. In other words, non-POE models have only a single network RJ45 port, which means they access all cameras over a single network connection instead of having a dedicated port direct to each camera. Am I assuming too much - that having a dedicated connection direct to each camera would have some performance gain inside the box (for image processing, recording bit-rate, etc) ?

As for the non-POE models, what exactly limits them in terms of the number of connected cameras when they access all cameras through a single network port?

 

[fenderman]

Correct me if I'm wrong, but with the Dahau 4-camera (and maybe also the 8-camera) DVR's only seem to have dedicated RJ45 ports for each camera if the DVR is a POE model. In other words, non-POE models have only a single network RJ45 port, which means they access all cameras over a single network connection instead of having a dedicated port direct to each camera. Am I assuming too much - that having a dedicated connection direct to each camera would have some performance gain inside the box (for image processing, recording bit-rate, etc) ?

As for the non-POE models, what exactly limits them in terms of the number of connected cameras when they access all cameras through a single network port?

You are incorrect. Also it's an NVR. The camera limit is set by the number of channels the NVR supports.

 

[sumguy]

> You are incorrect. Also it's an NVR.

Yea, I realized after I posted that these IP-camera recorders are usually called NVR's (N for Network?) even though the analog camera boxes (those are usually called DVR's - yes?) are also ethernet network-connectable (accessible).

> The camera limit is set by the number of channels the NVR supports

What I was trying to get across was the idea that an analog DVR can only record from as many cameras as it has RCA video-input ports.

An NVR with 4 ethernet IP-camera ports can be (or could be) limited to recording from only those ports in a similar way.

But for NVR's that don't have separate, dedicated RJ45 camera ports, then what exactly limits them in terms of the number of connectable cameras (besides internal CPU horsepower and ram) ?

And why wouldn't it lead to higher performance for those NVR's with dedicated IP-camera ports? Wouldn't you get better data throughput into the box if each camera had it's own "lane" or channel into the box?

 

[fenderman]

The manufacturer limits the number of cameras... The number of ports are irrelevant....
As far as better performance you're just misunderstanding basic networking.... There's no performance Improvement using built-in Poe ports can make it more difficult to access the camera directly...

 

[eggsan]

I was under the impression that using the internal switch of the poe nvr, while connecting the cameras to a different ip (i.e., 10.1.1.1), as compared to the main lan (i.e., 192.168.1.1), allows for better performance, at least while running under my internal network. Accessing remotely (bottleneck), makes no difference. I was wrong.

 

[fenderman]

I was under the impression that using the internal switch of the poe nvr, while connecting the cameras to a different ip (i.e., 10.1.1.1), as compared to the main lan (i.e., 192.168.1.1), allows for better performance, at least while running under my internal network. Accessing remotely (bottleneck), makes no difference. I was wrong.

As long as the cameras and nvr are connected to the same switch it's exactly the same..

 

[eggsan]

thks fenderman.