[Outages-discussion] [EXTERNAL] Re: Mediacom intermittent packet loss

[Matthew Petach]

The 12 seconds of jitter and 98% of the packets being tagged as "late
packets" really, really points to a pretty bad buffer bloat problem.

If other customers are seeing similar problems, it could be a cascading
series of large buffer devices along a pathway with an intermittently
congested series of upstream links beyond them, so what you're seeing isn't
just packets being stuck in a single large buffer, but a procession of
large buffers, each of which adds delay and loss.

Definitely not a good customer experience, that's for sure.  ^_^;

Matt


On Sat, Feb 19, 2022, 20:34 Chapman, Brad (NBCUniversal) <
Brad.Chapman at nbcuni.com> wrote:

> devicetests.com is interesting.  However, the latency / packet loss test
> is only capable of blasting a max of 450 KB/s (3.6Mbps) even when cranked
> to its maximum silliness... but his sample shows a *steadily increasing*
> ping time over the length of the test.  That's strange.
>
> It could be an oversubscribed line, or the original repair wasn't done
> right (or has failed again), or he just doesn't have sufficient bandwidth
> to stream at all.
>
> 1. What is his chosen streaming platform?
>
> 2. What is the resolution, frame rate, bitrate etc?
>
> 3. What is his *contracted* upload rate from Mediacom ("up to ____ Mbps
> upload")?
>
> 4. Has he run a 24-hour twitch stream to track the latency around the
> clock?  Maybe there's a pattern.
>
>
> —Sent from my iPhone
>
> On Feb 19, 2022, at 7:46 PM, Chad Austin <me at chadaustin.org> wrote:
>
> 22 seconds of latency?
>
> Do you have gigabytes of buffers, or is something sending pause frames?
>
> +1 to 'did you plug your PC into the modem directly?'
>
> -Chad
>
> On 2/19/2022 9:57 PM, Scott Buettner wrote:
>
> The cable carrier has done the standard "have him powercycle then send a
> tech out" and the techs have not found a problem in this most recent issue.
> (He had a similar problem in December that WAS line related and was
> resolved in early Jan by the carrier techs). Unfortunately he's on
> residential class service at the moment (which I am trying to persuade him
> to correct) so the level of support we're getting from the Tier 1 folks
> isn't ideal.
>
> He's scheduling another tech dispatch with them now, just to be safe.
>
>
> It's hitting TCP and UDP both, which is just manifesting in "slowness" on
> TCP of course. It's most relevant over UDP as he is a professional streamer
> and the most prominent symptom is frame drops on that, and I've confirmed
> it is affecting his connection in general, the issue is not specific to
> that service. I had him grab a packet loss test using devicetests.com
> (which looks to be based on WebRTC for the test) and we managed to grab
> results of it actively happening here:
> https://urldefense.com/v3/__https://dast-files.s3.us-east-2.amazonaws.com/packets.jpg__;!!PIZeeW5wscynRQ!78RScPexz65Gc0_sIwuwdK43Y9sa-rcED6XtN-khol5rNm3Sl80znvDY-x1vXl_u4w$
>
> He's replaced the modem and router both in the last 3 months, along with
> the cables.
>
> It's very intermittent, bursts of packet loss over a few minutes, then
> fine for some period of time (minutes to hours).
>
>
> He's informed me that a colleague of his located about 4 hours away on the
> same ISP is experiencing similar issues, but that individual is not a
> client of mine so I don't have anything concrete from that endpoint
> currently.
>
>
> I'm happy to keep discussing/troubleshooting, but I would like to avoid
> spamming the rest of the list (even -discuss), so feel free to email me
> directly.
>
>
> -----Original Message-----
>
> From: Jay R. Ashworth <jra at baylink.com>
>
> Sent: Saturday, February 19, 2022 7:18 PM
>
> To: Scott Buettner <DasterinTempus at outlook.com>
>
> Cc: outages-discussion at outages.org
>
> Subject: Re: [Outages-discussion] Mediacom intermittent packet loss
>
>
> ----- Original Message -----
>
> From: "Scott Buettner" <DasterinTempus at outlook.com>
>
> I hate to ask since this isn't really the forum, but I'm sort of out of
> ideas:
>
> Would anyone from MediacomCable be able to reach out to me offlist?
>
> I'm not gonna call it an outage, but I have a client on their service
>
> who is having crippling intermittent upload packet loss (~85%) for
>
> most of this month, calls from him to phone support have not resulted
>
> in a resolution and it's seriously affecting his home business.
>
>
> Thanks in advance if anyone can assist, and sorry to bother everyone
> otherwise.
>
> --Samantha
>
> The cable carrier has confirmed there's not a low-signal problem on the
> link, and other first-level stuff like that?  Do they have their own
> router, have they plugged directly into the cablemodem for test (after a
> powercycle)?
>
>
> What protocol isn't working, does other stuff not work too?
>
>
> You're right, this is usually out-of-scope for Outages, but at least you
> posted it on -discuss.  :-)
>
>
> Cheers,
>
> -- jra
>
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