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zooneylfc
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Packet loss since 26th Jan

Hi there

Package: Vivid 350
Area Reference: 05
Setup: Superhub 3.0 (modem mode), Netgear X4S R7800, Wired Windows 10 PC,

I've had packet loss issues since Saturday 26/01/19. It came on suddenly around 4pm and I noticed the impact of it immediately. I checked the service status and ran a test through my Virgin Media account and no issues were found. I restarted my router at this time, which did not help. It is probably worth mentioning that this looks very similar to an area fault I experienced a few months ago, which took weeks to get resolved.

See below a BQM graph for 26th Jan:

bqm-2601.png

The issue still persists as of today 30th Jan. Performing a ping via cmd to google.com 500 times shows ~3% packet loss. There is no packet loss when performing ping tests between local devices on my network. General browsing is minimally impacted, but watching live broadcasts and gaming are impacted quite heavily. Latency spikes are also much more frequent.

Here is a direct link to my live BQM graph:

 

https://www.thinkbroadband.com/broadband/monitoring/quality/share/1b75bf977768cd6e589c40a2e13b206c527d0f02

 

Below are the upstream/downstream from my hub, obtained by going to 192.168.100.1 and checking the router status from the login screen. The hub was last reset on Sunday 27/01 at 8pm.

Channel 4 and 11 stand out in particular for the Post RS figures. The network log is a long long list of repeated "Lost MDD Timeout" / "RCS Partial Service" warnings. Unable to find the devices the MAC addresses relate to.

Downstream bonded channels

 

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

12990000000.536256 qam17
23230000000.736256 qam20
3315000000-0.237256 qam19
43070000000.936256 qam18
52830000000.937256 qam15
62750000000.737256 qam14
72670000000.737256 qam13
82590000000.537256 qam12
92510000000.937256 qam11
10243000000037256 qam10
112350000000.533256 qam9
12227000000137256 qam8
132190000002.537256 qam7
142910000000.937256 qam16
152110000001.937256 qam6
162030000003.237256 qam5
171950000003.238256 qam4
181870000004.337256 qam3
19179000000438256 qam2
201710000005.337256 qam1



Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1Locked36.624849878000
2Locked36.623474758740
3Locked37.323760256930
4Locked36.62741327161278257300
5Locked37.324744492730
6Locked37.324770682720
7Locked37.324882039430
8Locked37.324578094600
9Locked37.325172284930
10Locked37.624101348710
11NotLocked32.66707463982990291554
12Locked37.623581442980
13Locked37.626396325050
14Locked37.324942021810
15Locked37.623502168500
16Locked37.627115462282
17Locked38.623491521490
18Locked37.324511627510
19Locked38.623824124560
20Locked37.622964752990

 

 

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

12440000040512032 qam27
23100000040.5512064 qam26



Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1ATDMA0000
2ATDMA0010

 

 

Network Log

Time Priority Description

2019-01-30 15:58:54.00Warning!Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-01-30 15:58:55.00Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-01-30 15:59:01.00Warning!Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-01-30 15:59:03.00Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

 

I'm hoping someone can provide some guidance of how to resolve the packet loss issue, I have been posting this issue in another larger packet loss thread but it has not garnered any response. I'm making my own thread so I can be as detailed as possible and hope someone able to help sees it.

My previous posts regarding this issue (including traceroutes and other BQM graphs) can be found at: https://community.virginmedia.com/t5/Gaming-Support/packet-loss/td-p/3901146/page/25

If any further information is wanted to help diagnose the issue, please let me know!

Many thanks in advance

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zooneylfc
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Re: Packet loss since 26th Jan

Just an update that the problem appears to have worsened overnight.

Traceroute via WinMTR, showing packet loss via aztw-core-2b-xe-301-0.network.virginmedia.net and eislou2-ic-3-ae0-0.network.virginmedia.net

winmtr 1000.PNG

 

Here's my latest BQM:

BQM 3101.png

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DreamOfCheese
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Re: Packet loss since 26th Jan

Check all the coax connections leading to the Hub are tightly and securely connected, if that doesn't fix it you need to call the support number and request an engineer (or wait a few days for a member of the forum team to respond here) as you're having issues with your downstream channels, one of them so badly it hasn't even acquired lock.

Tracerouting won't help diagnose this as from the info you've supplied so far, it's an issue with your connection to the street cabinet.
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zooneylfc
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Re: Packet loss since 26th Jan

Cheers for the help, DreamOfCheese.

Had a brainwave as I was going around tightening the coax connections as you suggested. Can't believe I didn't try it earlier.

I've had some success by removing a no longer needed coax splitter. This seemed to bring all the SNR levels up to where they should be. dBmV levels increased by ~3 as a result of removing the splitter. Maybe a bit on the high side at the top end? Not caused any new issues so far though.

Unfortunately I still had an unlocked channel. However, re-locating the hub to where my virgin tv box used to be and using a different coax cable made all channels lock (for the most part).

Channel 12 is intermittently showing as not locked, and some packet loss is still present. Post RS errors are still happening on that channel too. 

I will keep an eye on it and request an engineer if it persists. I think I've done just about everything possible. 

Here's my downstream after all the above tinkering (~30 mins uptime)

Downstream bonded channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

1299000000437256 qam17
23230000004.136256 qam20
33150000003.237256 qam19
43070000004.136256 qam18
52910000004.536256 qam16
62830000004.136256 qam15
7275000000437256 qam14
82670000004.137256 qam13
92590000003.937256 qam12
10251000000437256 qam11
112430000003.537256 qam10
122350000004.536256 qam9
132270000004.537256 qam8
142190000005.837256 qam7
152110000005.137256 qam6
162030000006.637256 qam5
171950000006.437256 qam4
181870000007.537256 qam3
191790000007.538256 qam2
201710000008.537256 qam1



Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

     
1Locked37.3157283690
2Locked36.3157940340
3Locked37.3150448000
4Locked36.6166447720
5Locked36.6161489310
6Locked36.6168628470
7Locked37.3157409600
8Locked37.3153937900
9Locked37.6155964600
10Locked37.3170403890
11Locked37.6151627830
12Locked36.8917292117567452
13Locked37.3156727506632
14Locked37.3168663040
15Locked37.6148874690
16Locked37.6174254950
17Locked37.6148715620
18Locked37.6154992600
19Locked38.6151183440
20Locked37.6145075430

 

Thanks again for the help. Will provide updates for anyone else to see if there are any more developments.

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zooneylfc
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Re: Packet loss since 26th Jan

The packet loss seems to have resolved itself as of 3am this morning. All channels have been locked every time I've checked today too.

I've not made any adjustments to my network since my previous post, so it leads me to believe that at least part of the problem was out of my hands.

3rd feb.png

I'll leave it there for now, unless the problem resurfaces.

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zooneylfc
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Re: Packet loss since 26th Jan

The problem came back within 24 hours of my previous post and continues to be an issue.

I've since moved my hub to my old tivo box spot using a different cable. I've removed a 3.5db splitter. I've tried modem mode with my own router and the default setup. I've reset my hub and ensured its on the latest firmware (.608). All coax connections are at least hand-tight. 

Downstream - Channel 12 has been the main culprit for the past week, not locking some of the time. Post RS figures on that channel hit 10 figures after 48 hours uptime consistently.

See below for a snapshot of my current router stats (1hr uptime, no splitter - not ideal but I was doing a last bit of tinkering and a reboot before deciding to post again).

Downstream bonded channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

1299000000437256 qam17
23230000004.336256 qam20
33150000003.437256 qam19
43070000004.336256 qam18
52910000004.536256 qam16
62830000004.336256 qam15
7275000000437256 qam14
82670000004.437256 qam13
92590000004.137256 qam12
102510000004.337256 qam11
112430000003.537256 qam10
122350000004.336256 qam9
132270000004.537256 qam8
142190000005.937256 qam7
152110000005.337256 qam6
162030000006.937256 qam5
171950000006.538256 qam4
181870000007.637256 qam3
191790000007.638256 qam2
201710000008.838256 qam1

  Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1Locked37.3257733580
2Locked36.627300652319
3Locked37.3249616690
4Locked36.6282168460
5Locked36.6270457050
6Locked36.6280712480
7Locked37.3261967690
8Locked37.3255781960
9Locked37.3256692070
10Locked37.3288325280
11Locked37.6252314300
12NotLocked36.62001793422929592
13Locked37.3258278550
14Locked37.3284274740
15Locked37.6247738310
16Locked37.6290886740
17Locked38.6247342960
18Locked37.6258188000
19Locked38.6250181900
20Locked38.6239885690

 

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

12440000036.5512064 qam27
23100000037512064 qam26



Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1ATDMA0000
2ATDMA0000

 

 

06-02.png

I'm convinced the issue stems either from a fault outside my home or from the superhub 3 itself.

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DreamOfCheese
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Re: Packet loss since 26th Jan

You've still got the issue with channel 12 not locking and having an extreme amount of Post RS Errors (along with every channel having an extreme amount of Pre RS Errors), you'll need to call it in as a fault for a technician to come check and fix supply.
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zooneylfc
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Re: Packet loss since 26th Jan

Technician came Saturday and was helpful. Replaced the Superhub and coax where it entered my house. As it was rebooting he went and checked the local tap down the street and realised the problem was rooted there. He didn't explain exactly the issue, but something wasn't giving out any signal.

The proper engineers are out on the street today looking into it more and running various tests, keeping me up to date along the way. The latest is that another team will probably need to come in from Bristol and finish the repairs, either today or tomorrow.

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