Regular lag spike problem. Quite a puzzle!

  • 3 July 2020
  • 8 replies
  • 805 views

For about the last half year or so, I’ve been putting up with regular lag spikes.  Every fifteen minutes, approximately, I experience two “pauses” in the shadow stream.  The video and the audio both freeze for a moment, unpause, then freeze again.   After that, the video encoding is messed up until I get a new keyframe.  It’s just two quick pauses, but it means for about ~20 seconds I can’t do anything.  The ping spikes are usually ~2000ms although they have gone as high as 16800ms.  https://i.imgur.com/IdGa3qy.png  This is a colossal annoyance because I do like to play games on the internet with other people.  In any sort of competitive fashion, regularly being unable to act for almost a half a minute is absolutely maddening.  There is no ping loss.  I get the same result but with differing looking symptoms whether I use TCP or UDP.  The shadow speed test shows great ping with negligible jitter.

All this said, I feel the need to say that I am pretty sure it’s NOT the shadow system itself.  It may be the laptop I’m using, it may be my home network, and I think it's probably some routine process jamming my network, or some spyware or malware on something.  I don’t know.

Troubleshooting so far:  I have done a complete reload of my laptop.  Since it was out of the box, I've only ever put shadow on it anyway, I treat it like a thin client anyway.  Once reloaded, I took the liberty of installing all the bloatware I can find.  For what it’s worth, it's an Acer Aspire 5 laptop.  My network uses Eero wifi, though I have a six tuner tivo with a Moca network, so I also have in my attic and where my workstation is a Moca bridge, so I can also use a pseudoethernet hard-line connection.  I experience the lag spikes both via wifi and via ethernet with no discernable difference.  I took the liberty of running WinMTR to do a sort of continuous traceroute to the shadow server.  After several lag spikes, I found no evidence of issues anywhere along the route, which tells me the problem is either me or the server.  I work nights, so I took the liberty of using the profiles system on Eero to disable the internet connection for everything except the laptop, the DVRs, and the two cell phones of ours on the network.  I saw no difference.  I work from home right now, and my workstation features a Polycom VOIP line.  During working hours and during long conference calls, I have noticed fifteen minute auditory silence pauses, suggesting that the problem isn’t confined to just my laptop.  My fiancee noticed similar weirdness with her workstation, also.  Now, I happen to work in the NOC for my ISP, so I have the unusual opportunity to go network side and look over the conditions of the modem in my house.  The SNR values are well within spec and the forward power levels are right where they should be.  I see no packet loss.  The provisioning is correct.  There’s nothing there I can see that suggests a problem between my modem and the node, and the node and the CMTS.  It isn’t a problem from CMTS to backbone because I would have taken a great many calls about that and my time in the last few months would have been far more miserable.  

Everything suggests a local, in-home-network problem, something regularly occuring every 15 minutes, that also manages to completely shut down traffic to everything on my network.  Using Erro, I can’t really see the throughput of my devices over time, but I can see the output of those devices at-that-moment, and I’ve literally had the profiles up of every device on my network, as lag spikes happen, and haven’t seen any appreciable difference on those devices that could explain this.

I am out of ideas and I don’t know where to go next.   I hope somebody here can suggest something I haven’t thought of or haven’t tried.  Oh, before I forget, I’ve tried both beta and the regular client.  Same on both.


8 replies

Userlevel 6
Badge +6

Can you tell who is your ISP and have you tried turning off any and all firewall settings in your router? 

Firewall’s kind of an all or nothing thing, isn’t it?  And no offense, but I’d rather not say who the ISP is.  I already mentioned I work in its NOC.  I believe I’ve already ruled that out;  WinMTR shows no jump in latency on any hop towards Shadow and the speedtest shows low ping and very low jitter.

I forgot to mention firewall was turned off.

Userlevel 6
Badge +6

Can you tell me the name of your router? Does it use the intel Puma chipset? 

I’m using a DG3450A three-on-one system with the wifi functionality disabled, with an Eero to provide wifi coverage.  The primary Tivo has an ethernet plug into the DG3450A, which is the root of the Moca network.  So using ethernet in my attic goes through a ethernet-over-coaxial bridge and effectively bypasses the eero.  Or I can connect to wifi, via the eero.  I see the same result either way.  I do not believe DG3450A uses Puma.

 

EDIT:  I stand corrected.   The DG3450A does appear to use Puma!

https://approvedmodemlist.com/intel-puma-6-modem-list-chipset-defects/

 

EDIT2:  Ok, that probably explains all of this.  Well, time to find mine own Docsis 3.1 modem!

Userlevel 5
Badge +4

Huh, I hadn’t heard of this Intel Puma 6 chipset defect thing. I’m using an Arris SB6190 (with Comcast), but haven’t experienced this problem.

@Whackjob keep us posted on whether a new cable modem solves your issue!

Userlevel 6
Badge +6

I’m using a DG3450A three-on-one system with the wifi functionality disabled, with an Eero to provide wifi coverage.  The primary Tivo has an ethernet plug into the DG3450A, which is the root of the Moca network.  So using ethernet in my attic goes through a ethernet-over-coaxial bridge and effectively bypasses the eero.  Or I can connect to wifi, via the eero.  I see the same result either way.  I do not believe DG3450A uses Puma.

 

EDIT:  I stand corrected.   The DG3450A does appear to use Puma!

https://approvedmodemlist.com/intel-puma-6-modem-list-chipset-defects/

 

EDIT2:  Ok, that probably explains all of this.  Well, time to find mine own Docsis 3.1 modem!

Alrighty, I'm glad that figured it out. 

Userlevel 3
Badge +1

Puma strikes again. What a terrible bug. 

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