High Pings and Ping Jitter with CGN3 and CGN3AC Modem

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I'm a Reliable Contributor
Posts: 157

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

Yeah, the latency is starting at your Gateway. It's almost like your upload speeds are saturated or the node inbound traffic from cable modems is saturated. 

 

I didn't look at your screenshots of cable modem signals, so I don't know if that's the issue, but there's is congestion on the near end. (Closest to you)

I Plan to Stick Around
Posts: 18

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

Downstream Signal Levels:

http://snag.gy/TGlmb.jpg

Upstream Signal Levels: 

 

http://snag.gy/h401a.jpg


Could you please further explain what you mean by congestion  on the near end/ gateway?

I would like to understand as much as possible as to keep finding the right information to tech support. I have an open ticket with them, and apparently their engineer's are looking into the issue.  

I'm a Reliable Contributor
Posts: 157

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

Sure. So basically what's happening is that the latency seems to be spiking at your gateway (your cable modems way to connect out to the internet and leave the "LAN" in a manner of speaking).

 

Unfortunately, I'm not a subject matter expert of cable modem signal levels. But, I believe if your Signal Strenth is below (and does nto encroaches) 50dBmV, you are OK. Someone can correct me if I'm wrong here.

 

I am somewhat of a subject matter expert on networks and networking. And when I say that there appears to be congestion on the near end, I mean that one or the combination of the following could be occurring:

 

- You are sending/receiving too much data on your internet connection to the point where your ping requests has you get into a queue, and wait for availability before it can send its packet out to check your internet timings.  Think of this as a traffic jam on the highway. You have to wait until the bottle neck aleaveates itself before you can go back to full speed again. This would be Saturation.

 

- The gateway that receives data directly from your cable modem may be congested/overloaded with data. The gateway not only does it have to deal with data from you, but data incoming from your neighbourhood. The gateway only has a certain amount of "listening power" if you will. If it gets overloaded, it can get to the point where it starts screaming "Stop, this is too much. I need all of you tell me what you need slower." This would be Congestion.

 

- Varoius other factors, but not limited to:

- Equipment problems

- Hardware faulting/failing

- Induced noise from unknown source

- High level of internet packet errors.

 

Unfortunately, finding the true source of the problem is not going to be easy. This is also something that a Rogers Tech support script reader may not have knowledge in troubleshooting since this is rarely a problem, not to mention complex issue in of itself. If you are lucky, you may get a knowledge tech to help you out.

 

What I would do is a lot of trial and error. Disconnect all devices from your router except 1 computer. On that computer, make sure no application is running that could be using the internet. (Web browsers, IM tools, File sync tools such as Dropbox, etc.) Run a traceroute/ping test to see if you notice the lag while your internet connection is mostly idle.

 

Then download a massive file. As the file is downloading, do another traceroute/ping test. Do you see the spike then? How about uploading a massive file somewhere. As you are upload the file, do another traceroute/ping test. Did the behaviour change at all?


Once you have all these data points, see if theres a Rogers tech willing to collect this data from you to help resolve the issue. This would be either by phoning in, tweeting to @rogershelps, using the facebook Rogers page, maybe a Rogers rep is watching this forum post and can lend a hand.

 

Hopefully with all the data collected, a Rogers tech can escalate the issue to someone that can say "Yes, there's a problem here and I can fix it."

Resident Expert
Resident Expert
Posts: 14,033

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

The downstream power levels are pretty much bang on.

The upstreams.. while still within spec.. are a little on the lowe side.  That COULD cause upload issues possibly.
Could be an issue just on the freqency range used for those channels.

Getting a tech out, replacing splitters/connectors might fix that.



Resident Expert
Resident Expert
Posts: 6,297

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

Reading back through the thread, you have already had a tech out to replace cabling and connectors.  The signal levels are fine, so that shouldn't be an issue.  Have you had any luck using PSPING for testing?  Unfortunately, the modem ping times and latency with the CGN3 and CGN3ACR are here until Hitron issues a fix, so that is part of the problem, modem latency combined with network latency.  When the modem issues are finally addressed, everyone will be able to see the real latency within the network.  I wonder if you are running into node congestion?  Have you ever asked the CSR how many people are on the node that you are running on?  That would be worth knowing, as well as whether you are in a house or apartment.

 

Can you provide a little explanation for this previous post:  "When I do a speed test on http://www.speedtest.net, I noticed that my pings stabilize when the download test is being performed. However, once I do the upload test, my pings instantly jump to 200 ms + on each packet."

 

How do you manage to see a ping time for the upload portion of the test?  I only see a single ping time come up at the start of the download test, and that number remains as is, for all of the download and upload test.  Is that ping time dynamic and does it change as the upload test commences?



Resident Expert
Resident Expert
Posts: 14,033

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

Unless they were doing a manual ping, seperately, while running the speed test?

And with that.. i could SEE the ping times go up a bit.. as you are saturating your connection for a little bit while running the speed test.



Resident Expert
Resident Expert
Posts: 6,297

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

Maybe, and here is what it looks like on a CGN3 with the 250/20 Mb/s service.  This is an excerpt of a ping test running while running a speed test from the speedtest.net Toronto Telus server:

 

 

Pinging www.google.ca [74.125.226.119] with 32 bytes of data:


Reply from 74.125.226.119: bytes=32 time=52ms TTL=56
Reply from 74.125.226.119: bytes=32 time=51ms TTL=56
Reply from 74.125.226.119: bytes=32 time=55ms TTL=56
Reply from 74.125.226.119: bytes=32 time=44ms TTL=56
Reply from 74.125.226.119: bytes=32 time=63ms TTL=56
Reply from 74.125.226.119: bytes=32 time=34ms TTL=56
Reply from 74.125.226.119: bytes=32 time=40ms TTL=56
Reply from 74.125.226.119: bytes=32 time=35ms TTL=56
Reply from 74.125.226.119: bytes=32 time=30ms TTL=56
Reply from 74.125.226.119: bytes=32 time=35ms TTL=56
Reply from 74.125.226.119: bytes=32 time=27ms TTL=56
Reply from 74.125.226.119: bytes=32 time=2369ms TTL=56
Reply from 74.125.226.119: bytes=32 time=123ms TTL=56
Reply from 74.125.226.119: bytes=32 time=133ms TTL=56
Reply from 74.125.226.119: bytes=32 time=154ms TTL=56
Reply from 74.125.226.119: bytes=32 time=154ms TTL=56
Reply from 74.125.226.119: bytes=32 time=129ms TTL=56
Reply from 74.125.226.119: bytes=32 time=137ms TTL=56
Reply from 74.125.226.119: bytes=32 time=146ms TTL=56
Reply from 74.125.226.119: bytes=32 time=142ms TTL=56
Reply from 74.125.226.119: bytes=32 time=136ms TTL=56
Reply from 74.125.226.119: bytes=32 time=191ms TTL=56
Reply from 74.125.226.119: bytes=32 time=146ms TTL=56
Reply from 74.125.226.119: bytes=32 time=59ms TTL=56
Reply from 74.125.226.119: bytes=32 time=81ms TTL=56

 

The ping reply times when the upload test runs are about 4 to 5 times what they are when the download test is running just before the numbers increase.  There is a really large 2369 ms spike when the upload test starts to run.



I'm a Reliable Contributor
Posts: 157

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

That's a perfect example of Saturation. Your internet connection is so full of data that some of it is getting queued for transmission.

I'm Here A Lot
Posts: 6

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

@s1lva166  did you end up ever fixing the issue and how was it fixed? I'm experiencing the EXACT SAME THING, the jitter becomes the WORST in the hours of 7pm-midnight, I'm gettin constant 30-60 ms jitter and during the daytime I get about 15-20ms which is still odd. 

 

Please reply if you see this, i've had a tech come out and replace the line going into the pole and that was about it.. I call them everyday and I'm just ready to give up.

I Plan to Stick Around
Posts: 35

Re: High Pings and Ping Jitter with CGN3 and CGN3AC Modem

I have the same issue. It has nothing to do with wires, splitters etc. The problem is the new modem and the new plans (the way Rogers routers the data and the overloading of nodes). When I had the older cisco modem and the HSE Unlimited plan everything was great, great latency, fast speed. With the change to the new 100u plan everything went down the toilet. I hope they can fix it and soon...