Packet loss, jittery image at times

[ermac]

Hi, I notice on the live feed from my DH-SD49225T PTZ that it can be a bit jittery on large scenes with fast moving objects. Seems to be less so when the camera is zoomed in on a smaller area.

Recorded playback seems to be smooth and so does live view on mobile devices.

The DH-SD49225T IP PTZ in plugged into an XVR with multiple HDCVI cameras connected.

Bit rate is set at 5120kbps (max incoming stream allowed per channel for IP cameras on my Dahua XVR) on CBR at max frame rate 25FPS (pal region).

I ran a ping test for about 3 minutes (laptop plugged in with network cable direct into switch). This is the result:

• Is it normal for any packet loss to occur when pinging an IP camera?
• Would this packet loss mean there is an issue, or is it acceptable?
• And are the ping speed results fast enough?

 

[IAmATeaf]

I wouldn’t expect there to be any packet loss, that is what is most likely the cause of the jitter you are seeing.

 

[SouthernYankee]

there is no need to mask the local IP address.
That is a very long time for a ping on a local network.

Provide a diagram of the network, with equipment names and model numbers.
What is the distance between the pinging device and the camera ? How many devices does it travel through?
What device are you recording to ?
Are the cables premade purchased or did you make them ? If you made the cables how did you test them ?

On all camera disable the sub streams.
Set iframe and frame to 15 or less.
No local camera traffic passes through the router.

 

[ermac]

• I am recording to a Dahua XVR 7216A.
• Distance between pinging device and camera is approx 62 meters (203 feet).
• A mix of bought patch cables and installation cable. All the Ubiquity ToughCable Pro installation cable endpoints made by the installer on-site. All connections were tested with a RJ45 testing device.
• See attached network layout diagram in PDF...

 

[SouthernYankee]

Excellent network diagram.

Do a ping test without going through the router.

For testing only, remove the lighting protector and the injector. Connect the camera directly to the Netgear switch using one of the POE ports. If the poe ports are not Being used then it should have enough power to drive the camera.

I am not a fan of injectors. Look at netgear GS108LP with a big power supply.

 

[bigredfish]

Thats odd, I have a 7216A and am running (9) 2MP CVI cameras at 6144 record and Motion, 30FPS, the other three at 6144 15FPS along with one new 4MP IP camera at full resolution and 8192 /30FPS and have no problem.
I run the substream at D1 on all at 512kb/s and 7-15 fps

 

[ermac]

Thanks for the replies.

@SouthernYankee will do the tests as you suggested and see the results. Must be an issue between the Netgear switch and camera, so maybe the PoE+ injector or lightning protector or the cable connections there, because I ran a ping test from the same laptop connected on the router to the XVR, it came back with 0% packet loss which means at least that part of the network is in good health.

@bigredfish I tried to set the bit rate for that channel to 8192, that channel totally bombed out. Had to login to the camera from the web interface and lower the bitrate so that I could get the channel working on the 7216A again. The 7216A is running the latest available firmware. Unfortunately I can't set the bitrate higher than 5120 for the IP channel. So yeah, it is weird you can run at a higher bit rate. I have the same HDCVI cams as you, running them at 6144 too with MD and record and max frame rate (25fps as I am in a pal region). All channels sub stream are also on D1 but on 1024.

 

[ermac]

Just checked out the GS108LP. Would have been a much better choice instead of the GS108P and a PoE+ injector. Also it would have eliminated two connections on the route (the connections going in and out of the PoE+ injector).

 

[ermac]

@bigredfish I think you have the 4MP or 8MP 7216A model, either the 7216A-4M / 7216AN-4M or the 7216A-4KL. Could explain how you can run a bit rate of 8192kbps on the IP channels. My 7216A is the 2MP (1080p) decoder.

 

[bigredfish]

Ahhh yes you’re correct. AN-4M

 

[catcamstar]

Just checked out the GS108LP. Would have been a much better choice instead of the GS108P and a PoE+ injector. Also it would have eliminated two connections on the route (the connections going in and out of the PoE+ injector).

For debugging purposes, try to eliminate all "unnecessary" hops (cable 1.5m with POE). If test is successful, you add the following component. Packet loss and those high response times indeed indicate bad network, especially when on your LAN. My advice: every entry & exit point can be faulty, either your cable plugs, or your switch port, or your injectors. Do the puzzling until you see packet loss appearing, and then you know the root cause. Switching netgears might be an intelligent thing, but if the cable to the pole is bad, it won't fix the issue at stake.

Good luck!
CC

 

[ermac]

Just an update and interesting observation. So before I started unplugging cables and start the troubleshooting, I shutdown the XVR completely and then pinged the camera from the switch in the office. No packet loss! and sub 1ms ping times. Also very consistent. I think it is safe to say that would mean it is unlikely an issue with the cabling or any of the the RJ45 connections between the first switch and the PTZ.

So could this have something to do with the XVR, its processing power, the cameras processing power and the streaming from the camera to the XVR that would be causing packet loss when pinging the camera?