azdeltawye's profile

Contributor

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51 Messages

Mon, Apr 26, 2021 10:47 PM

Closed

IPv4 Packet loss on windy afternoons

Hello,

I have been working from home for over a year now and my Comcast/Xfinity internet performance has been very reliable, until now...

Starting on 4/21, my connection has been experiencing severe intermittent packet loss (1% - 20%). This seems to happen around 13:00 and continues until about 17:00, especially when its windy outside. I logged into my modem to check the logs (Motorola MB8600) and nothing over a notice level 6 (message sent). My signal-noise and signal levels are very good (SNR: 39.4 - 40.1 dB) and -2 to 0.2 dBmV respectively on the main channels (1-32). My OFDM channel 33, however, is not very healthy at all with a SNR of 0 dB and signal level of -7.1 dBmV. Speed tests have been fine, even in the afternoons, 80-100/4-6 Mbps on a 100/5 Mbps tier.

Any idea of how to troubleshoot further? I think the problem is upstream with the CMTS but getting comcast/xfinity to do anything other than take my monthly payment seems unlikely at best...

One more tidbit, which may be significant, there have been two new cable hookups in my neighborhood recently; one neighbor on my node and another on an adjacent circuit. This seems more causal than coincident. 

Oh, one last detail: I'm only having trouble on IPv4, my IPv6 connection seems to be pretty solid. Unfortunately my work VPN only supports IPv4 so that doesn't help much..

Any help would be greatly appreciated!

azdeltawye

Contributor

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51 Messages

1 y ago

Update 6/24/21: Yesterday during a period of heavy use (1630 – 1730) I did experience moderate packet loss and also experienced above average latency (bufferbloat). This latency occurred on both on the IPv4 and IPv6 interfaces whereas the packet losses only occurred on the IPv4 connection. As you can see from the graph below, the average latency shot up from around 10ms to over 250ms. This is almost an order of magnitude greater than previous high-usage times! (see graph in previous post).

 

So I’m not sure what has changed in the system but it is not for the better…

(edited)

Official Employee

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655 Messages

Hi, @azdeltawye. I'll gladly dive in on my end to help investigate this further. I can certainly check your network and the surrounding area for any possible issues. I ask that you reach out privately, so we can cover the details of your account. You can start by clicking the chat icon located in the top right corner of your forums page when signed in. Once there, you can search for "Xfinity Support" to compose your private message. Please add your first and last name to help us locate your account. Let me know if you have any questions.

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
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azdeltawye

Contributor

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51 Messages

1 y ago

Update 6/29/21: Yesterday was windy and last night we had some substantial wind gusts. I woke up this morning to find lawn furniture and whatnot scattered all over the back yard... I was hopeful that the wind-related packet loss issues were mostly resolved but unfortunately, that appears to not be the case. Attached below are the Gateway ping statistics from my router showing significant packet losses between 10 pm and 1 am.

XfinityAbbie

Official Employee

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1K Messages

I am sorry to hear you are still having issues. I would like to assist you further.

 

Can you please reach out through private message (by clicking on the chat icon on the top right of the page) with your first and last name, name on the account if different, and service address?

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick
azdeltawye

Contributor

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51 Messages

1 y ago

Update 7/5/21: Monsoon season has started in the desert southwest! Friday 7/2/21 we had a good storm roll through the area in the afternoon. The outflow winds prior to the storm were substantial, and sure-enough, the packet losses started occurring like clockwork. One interesting observation however was when the rain started, the packet loss errors dissipated. I was watching the router GUI at the time and observed the packet loss issue completely disappeared the moment the rain started, even though the high winds persisted for the duration of the storm... My hypothesis; since water is conductive in the radio frequency band used for cable internet, the rain effectively lowered the resistance of a loose connection out on the ridged coax lines, line amplifiers or tap blocks out in the field. See screenshot below brief packet loss prior to the storm.

azdeltawye

Contributor

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51 Messages

1 y ago

Update 7/13/21:

 

Last night at around 9:30 pm, my residence got hit by a large monsoon storm. Like a typical monsoon, it started with high winds from the outflow of the approaching storm, then the ‘big drops’ start and ensuing deluge occurs for about 15 minutes or so. These storms are quite exciting and very welcome in the drought-stricken desert…

 

During this storm I closely watched the quality of my internet connection and made the following observations:

  • 21:40 – outflow winds start from the approaching storm
  • 21:45 – packet losses start occurring, ranging from 3% – 43% (see attached screenshot below)
  • 21:53 – rain begins
  • 21:56 – packet losses drop to 0%
  • 22:20 – wind and rain subside

 

This same exact sequence of events with a similar timeline played out on three other separate occasions that occurred at my residence prior:

  • 7/2/21 @ 3:00 pm (reported in my post on 7/5/21)
  • 7/7/21 @ 8:30 pm
  • 7/10/21 @ 8:10 pm

 

To explain what may be happening to my internet connection I will reiterate my working hypothesis with greater detail and clarity:

The possible root cause of the issue I am experiencing with my Xfinity internet appears to be what I will call a ‘loose connection’ in the aerial equipment (rigid coax, line amplifiers, tap blocks, etc.) in my neighborhood or near my house. This ‘loose connection’ appears to be aggravated by localized movement from windy conditions; either gusts or sustained winds in the magnitude of around 30 mph or greater. When this ‘loose connection’ acts up or is aggravated by the wind, I will experience dropped packets which adversely affects the quality of video conferencing and VOIP calls that I rely on for work. This packet loss condition appears to subside when the aerial equipment has become wet from the rain. Since water is conductive in the RF band used for cable internet, the rain effectively lowers the resistance of the ‘loose connection’ and temporarily resolves the issue even though the high winds typically continue throughout the duration of the storm. The dropped packets are tracked by a dpinger utility running on my pfSense router which pings the Comcast gateway (first-hop IP address) and reports in percentage packet loss.

New Poster

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11 Messages

@azdeltawye Did you ever get this resolved? I am having a similar issue 

EG

Expert

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95.1K Messages

10 m ago

@RedWings13 

Please create a new topic of your own here on this board detailing your issue. Thanks. The original poster has not recently returned.  6 month old dead thread now being closed.

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