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Swi1ch
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Latency on the high side, packets lost or late - High Pre-RS Errors?

200MB only package, everything wired directly by ethernet. Speedtest is reporting 20/200~ fine whenever I run it.

Experiencing consistent small % packets late/lost which is affecting my ability to play games. Packet loss gets stronger and more consistent if there's any Amazon/Twitch streams running. 

Checking packets with https://packetlosstest.com/ - generally seeing ~1% loss on upload/download and 2%~ late - increase by a % point or so when watching a stream.

BQM been running for a while and generally seems ok - it doesn't really correlate with my issue as this is pretty much all of the time and the BQM is showing congestion only in peak times. 

https://www.thinkbroadband.com/broadband/monitoring/quality/share/80d52351e9da94fe888d52c1c366c39d2381db6a

Had a look at my router stats and compared it to a few on the forums - it looks like I might be experiencing a lot of Pre-RS errors? Not sure what the threshold is for an issue but there's posts where the router stats have far, far fewer.

Downstream

Spoiler
Downstream bonded channelsChannel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1411000000-4.738256 qam33
2219000000-0.738256 qam11
3227000000-138256 qam12
4235000000-138256 qam13
5243000000-1.538256 qam14
6251000000-1.738256 qam15
7259000000-238256 qam16
8267000000-2.538256 qam17
9275000000-2.738256 qam18
10283000000-2.738256 qam19
11291000000-3.238256 qam20
12299000000-3.538256 qam21
13307000000-3.538256 qam22
14315000000-3.738256 qam23
15323000000-3.738256 qam24
16347000000-3.738256 qam25
17355000000-3.738256 qam26
18363000000-3.738256 qam27
19371000000-438256 qam28
20379000000-438256 qam29
21387000000-4.238256 qam30
22395000000-4.738256 qam31
23403000000-4.538256 qam32
24419000000-5.238256 qam34


Downstream bonded channelsChannel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1Locked38.938326
2Locked38.6280
3Locked38.9330
4Locked38.9510
5Locked38.9460
6Locked38.6460
7Locked38.9450
8Locked38.9720
9Locked38.91030
10Locked38.91090
11Locked38.91570
12Locked38.62100
13Locked38.92101
14Locked38.92740
15Locked38.92440
16Locked38.91810
17Locked38.91400
18Locked38.91660
19Locked38.91940
20Locked38.62340
21Locked38.62450
22Locked38.63590
23Locked38.92710
24Locked38.64830

Upstream

Spoiler
Upstream bonded channelsChannel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1461999594.7512064 qam3
2326000004.65512064 qam5
3394000004.7512064 qam4
4537000004.85512064 qam2


Upstream bonded channelsChannel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1ATDMA0000
2ATDMA0000
3ATDMA0000
4ATDMA0000

 

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lucianocantrell
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Re: Latency on the high side, packets lost or late - High Pre-RS Errors?

Hello,

Are you sure the problem is with the Pre-RS? What device are you using? Is your problem continuous or do you experience instant latency?

Best regards.
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Swi1ch
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Re: Latency on the high side, packets lost or late - High Pre-RS Errors?

I have no idea what Pre-RS even means, just that the log lists a lot of errors under that column.

Using a desktop PC. Consistent 1%~ packet loss, jumps instantly to 2%~+ if I load the connection a little heavier (Streaming 1080p, for example)
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Andrew-G
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Re: Latency on the high side, packets lost or late - High Pre-RS Errors?

When you posted the data, channel 24 was just out of spec at -5.2dBmV, which won't help things, but the BQM strongly suggests borderline over-utilisation.  That's where there's too much traffic for the capacity of the local network, and data packets get queued before they can be processed.  As I say it is (by VM standards) borderline, but still a poor experience for gamers.

These over-utilisation problems usually take months and months to get fixed, and whilst there's hope that the ongoing roll out of DOCSIS 3.1 across the VM network may be a solution, that won't be complete until the end of 2021, and the benefits may then take many months to appear.  Do not believe any VM claims that (a) there's no over-utilisation, as the BQM is a classic fingerprint, nor (b) any claimed fix date - VM routinely offer fix dates for over-utilisation and then do nothing.

If you're the bill payer, and you're not in contract, then your quickest fix may well be to find a good, smaller Openreach ISP.   When I say "good", I mean that - somebody who's sales and provisioning teams know what they're talking about, won't lie to you, and can give you a good idea of what service to expect from your Openreach connection.  This means companies like AAISP, uno, IDNet, Zen Internet, Aquiss or CIX.  It specifically means not Sky/Now, Talktalk, Vodafone, EE and the like.

I'd like to offer more constructive advice that would get this resolved by VM, and I'd invite contributions by others who disagree with me, but sadly I'm not hopeful.

I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more

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Swi1ch
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Re: Latency on the high side, packets lost or late - High Pre-RS Errors?

I was worried it might be that. I went through two periods of this at my previous residence with Virgin. 

Could you give me a little insight on looking into smaller ISPs? I've never looked before and not really sure what (if any) questions I should be asking them. Had a peek at a couple of your suggestions and they mostly list the same sort of information as other ISPs, e.g. expected speeds. Can I straight up ask them about line quality, over-utilisation and the like?

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