Cameras slow when plugged into Dahua NVR switch

[mephisto_uk]

I have a very weird situation where cameras plugged into the dahua NVR switch are sort of skipping frames or is slowing down and then is speeding up when doing life view but when I plug the same cameras a normal network switch and then connect that switch to the NVR everything behaves as it should. It is very weird and I have tried different ports on the NVR, different settings on the camera and it's still I can always see the video accelerating a bit and sometimes it's slowing down and sometimes skipping frames. Has anyone experienced this before?

 

[TonyR]

Based on the TOTAL camera megapixels (resolution) you're attempting to connect, are you right at or exceeding the NVR's rated total bandwidth ?

Bandwidth calculator | CCTV Calculator

CCTV Calculator is a tool designated for camera system basic parameters determination and testing. It enables easy calculation of an appropriate lens focal length, camera viewing angle, IP camera bandwith, storage capacity for records archiving and of other camera system parameters.

www.cctvcalculator.net

 

[Flintstone61]

Yes. I have experienced this. So now all my cams are off the NVR. I run BI and an NVR. logging into the cams while attached to the NVR direct was slow as f.

 

[mephisto_uk]

Based on the TOTAL camera megapixels (resolution) you're attempting to connect, are you right at or exceeding the NVR's rated total bandwidth ?

Bandwidth calculator | CCTV Calculator

CCTV Calculator is a tool designated for camera system basic parameters determination and testing. It enables easy calculation of an appropriate lens focal length, camera viewing angle, IP camera bandwith, storage capacity for records archiving and of other camera system parameters.

www.cctvcalculator.net

I don't think so, otherwise I would experience the same using an external network switch, right?

Yes. I have experienced this. So now all my cams are off the NVR. I run BI and an NVR. logging into the cams while attached to the NVR direct was slow as f.

Thanks for confirming. I can't understand how Dahua let's things like this escape quality control... Is this bad firmware or is it the hardware?

 

[Flintstone61]

It's not Gig speed ethernet on the NVR interface. some are like 80Mbps, and with streaming traffic heading in and out, your available bandwidth for surfing thru the cams is probably not ideal.
Also helps if your using a good Surveillance rated Hard drive that is built to deal with multiple streams. Some desktop drives just dont quite cut the Mustard in my experience.

 

[mephisto_uk]

It's not Gig speed ethernet on the NVR interface. some are like 80Mbps, and with streaming traffic heading in and out, your available bandwidth for surfing thru the cams is probably not ideal.
Also helps if your using a good Surveillance rated Hard drive that is built to deal with multiple streams. Some desktop drives just dont quite cut the Mustard in my experience.

But the interface from NVR to network is gbit, the cameras are like 10mbit max normally, so I would not be anywhere near the limits. even with the ports at 100mbit, and the NVR 1gbit downlink should be plenty. I wonder if the stream is relayed via the NVR or if I stream directly from the camera, but still would not make sense that even 2 or more streams out of the camera would not saturate 100mbit link, the cameras are all 100mbit anyway when plugged into a normal POE switch.

I have a enterprise grade 7200rpm disk with 512mb cache, it is as fast as it can be, but this should not affect at all live streaming from cameras. That does not touch the disk. I'm not watching recordings, I'm testing live camera streaming.

It is just an odd, behaviour from this NVR, and I dare to say sounds like software/hardware badly put together.

 

[Flintstone61]

Also we’ve had discussions here about an NVR slowing down in responsiveness if the Nvr ports are full or nearly full. Like 7-8 cams in an 8ch Nvr.

 

[mephisto_uk]

In mine, I just added 3 cameras to the Poe ports, all of them had the odd skipping a second here and there. Slowing down and speeding up from time to time.