Menu
Reply
Highlighted
  • 441
  • 11
  • 62
Fibre optic
918 Views
Message 1 of 15
Flag for a moderator

Bracknell Gig1 Stats

Hello All

I have recently came back to VM and went for their Gig1 speeds. All seems well however I did notice my DS Power levels were way out and I put on a 10db Attenuator that VM left in the past. However I am seeing a lot of T3 and a few T4 time outs on the upstream. Can someone check over my stats.

Stats ibelow and my TBB graph looks fine:

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 411000000 2.700001 38.983261 QAM256 1
0


UNSUPPORTED 0
2 419000000 2.700001 38.983261 QAM256 2
3 427000000 2.700001 40.366287 QAM256 3
4 435000000 2.700001 40.366287 QAM256 4
5 443000000 2.799999 38.983261 QAM256 5
6 451000000 2.500000 38.983261 QAM256 6
7 459000000 1.500000 38.983261 QAM256 7
8 467000000 0.900002 38.983261 QAM256 8
9 475000000 1.500000 38.605377 QAM256 9
10 483000000 2.000000 38.983261 QAM256 10
11 491000000 2.000000 38.983261 QAM256 11
12 499000000 2.000000 38.983261 QAM256 12
13 507000000 2.000000 40.366287 QAM256 13
14 515000000 2.200001 38.983261 QAM256 14
15 523000000 2.200001 40.366287 QAM256 15
16 531000000 2.000000 38.983261 QAM256 16
17 539000000 1.900002 38.983261 QAM256 17
18 547000000 2.000000 38.983261 QAM256 18
19 555000000 2.000000 38.983261 QAM256 19
20 563000000 1.700001 38.983261 QAM256 20
21 571000000 1.500000 40.366287 QAM256 21
22 579000000 1.400002 38.983261 QAM256 22
23 587000000 1.599998 38.983261 QAM256 23
24 595000000 1.500000 38.983261 QAM256 24
25 603000000 1.099998 38.983261 QAM256 25
26 611000000 0.500000 38.605377 QAM256 26
27 619000000 0.599998 38.983261 QAM256 27
28 627000000 0.799999 38.983261 QAM256 28
29 635000000 0.799999 38.605377 QAM256 29
30 643000000 0.400002 38.605377 QAM256 30
31 651000000 0.400002 38.983261 QAM256 31

 

Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 0 9 0
0 NotLocked 0 0 0
2 Locked 3406243675 8 0
3 Locked 576699225 7 0
4 Locked 521915505 9 0
5 Locked 402715992 12 0
6 Locked 466561416 12 0
7 Locked 3854934791 14 0
8 Locked 2214867504 24 0
9 Locked 123720872 20 0
10 Locked 125443267 31 0
11 Locked 280802566 22 0
12 Locked 4289269178 33 0
13 Locked 4052959350 35 0
14 Locked 4180736160 44 0
15 Locked 48259388 50 0
16 Locked 4112857110 45 0
17 Locked 4083642692 47 0
18 Locked 4024775076 52 0
19 Locked 4222489358 73 0
20 Locked 3968938310 71 0
21 Locked 3877985006 60 0
22 Locked 3844671336 80 0
23 Locked 4055876899 100 0
24 Locked 450983406 109 0
25 Locked 267268933 94 0
26 Locked 330543345 144 0
27 Locked 287664088 117 0
28 Locked 794269485 152 0
29 Locked 734407004 152 0
30 Locked 1424074278 167 0
31 Locked 95666186 148 0


Upstream bonded channels
Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1 46200000 24.020599 5120 KSym/sec 64QAM 3
2 39400000 24.020599 5120 KSym/sec 64QAM 4
3 53700000 24.520599 5120 KSym/sec 64QAM 2
4 60300000 25.520599 5120 KSym/sec 64QAM 1

 

Upstream bonded channels
Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1 US_TYPE_STDMA 0 0 8503 3
2 US_TYPE_STDMA 0 0 8503 3
3 US_TYPE_STDMA 0 0 8503 3
4 US_TYPE_STDMA 0 0 8503 3

Thanks

----------------------------------------------------------
ThinkBroadband Quality Graph Gig1

If my post helped you please remember to Kudos me 😉

Tazz
0 Kudos
Reply
Highlighted
  • 3.52K
  • 567
  • 1.38K
Very Insightful Person
Very Insightful Person
898 Views
Message 2 of 15
Flag for a moderator

Re: Bracknell Gig1 Stats

There's a heck of a lot of downstream pre-RS errors.  Those "preRS" are the one the hub identifies and corrects, but that error correction processing will worsen latency.  On your upstream, the power levels would be way too low if you had a Hub 3 (IIRC the lower limit for upstream power is 33 dBmV, you're showing 24.  Whether the Hub 4 has different operating limits for power and SNR I can't say for certain, but I'd doubt it, so it looks like you'll need a technician to visit (which might be a while at this time of year).  Easiest option is probably to wait for the forum staff to pick this up and advise on how VM can resolve it.  

Curious BQM - there was another Hub 4 user with intensely cyclical latency spiking posted a couple of days back, and yours looks similar, in which case the latency spikes may be unrelated to the appalling error performance. 

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

Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks

0 Kudos
Reply
Highlighted
  • 441
  • 11
  • 62
Fibre optic
887 Views
Message 3 of 15
Flag for a moderator

Re: Bracknell Gig1 Stats

Hi Andruser

 

I thought as much that SNR is way to low. The line does seem OK but I would like it fixed. Also the Hub4 has only recently started doing that. I think they are the built in sam knows speed test doing something. I did get an account message saying the following:

We're working on allowing diagnostic tests on the shiny new Virgin Media Hub 4. We're nearly there, so watch this space

I am guessing I need to be moved in the cab to a different tap? The service was still connected from when I was with VM years ago but is likely has been moved to the wrong tap for my distance to the cab.

Tazz

----------------------------------------------------------
ThinkBroadband Quality Graph Gig1

If my post helped you please remember to Kudos me 😉

Tazz
0 Kudos
Reply
Highlighted
  • 3.52K
  • 567
  • 1.38K
Very Insightful Person
Very Insightful Person
873 Views
Message 4 of 15
Flag for a moderator

Re: Bracknell Gig1 Stats

I did get an account message saying they were improving the self testing on the Hub4.

I've previously mouthed off that VM haven't done this, and may yet be forced to eat those words.  Overall, it sounds good but there appear to be two caveats for VM to address before I need to fire up my printer and get out the ketchup:

1) There's no excuse for the latency spikes - "dial home" doesn't have to be a higher priority than doing the job the customer wants doing.

2) There's no point dialling home if there is no one at home.  In this case, your hub should have reported the error performance and power levels, AND SOMEBODY SHOULD HAVE DONE SOMETHING about the underlying problem.  And not just a marketing email boasting about improved diagnostics about which they don't seem to do anything.

 

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

Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks

Highlighted
  • 49
  • 0
  • 6
On our wavelength
849 Views
Message 5 of 15
Flag for a moderator

Re: Bracknell Gig1 Stats

Is the modem connected to an amplifier? The levels suggest that. Try bypassing it.
0 Kudos
Reply
Highlighted
  • 3.76K
  • 55
  • 892
Community elder
819 Views
Message 6 of 15
Flag for a moderator

Re: Bracknell Gig1 Stats

The downstream is fine. Zero post-RS, less than 200 pre-RS. 

The upstream looks horrible. Thousands of T3 timeouts and some T4s according to the numbers.

The transmit power is way too low and as a result your upstream transmission is getting drowned out by noise.

It's not an area fault. The upstreams are 64 QAM.

An attenuator, not just a forward path one, or a change of tap will help. The attenuator you need should start at 5 MHz. 

The poster above me makes a good point. If there's a return path amplifier it needs removing.

The area as a whole, maybe just your cabinet, needs some adjustment. There's too much amplification or not enough attenuation on the return/upstream path, and the same for the return path. They need aligning. 

0 Kudos
Reply
Highlighted
  • 3.52K
  • 567
  • 1.38K
Very Insightful Person
Very Insightful Person
814 Views
Message 7 of 15
Flag for a moderator

Re: Bracknell Gig1 Stats

Carl is right.  In my enthusiasm to help I've mistaken non-round number channel frequencies for error numbers.  This is what happens when you rely on unpaid staff (maybe that explains VM's first line support?).

Now where's my "Talks **** sometimes" badge for the forum?

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

Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks

0 Kudos
Reply
Highlighted
  • 441
  • 11
  • 62
Fibre optic
784 Views
Message 8 of 15
Flag for a moderator

Re: Bracknell Gig1 Stats

Hi Guys

I checked and there is no return path amplifier that I can see I checked the White box and there is one of these he fitted when it was installed because of a faulty isolator - Teleste-GISX101-VM01 GALVANIC isolator

I tried removing this and the 10db Forward path and the US stats did not change. Put them back now.
----------------------------------------------------------
ThinkBroadband Quality Graph Gig1

If my post helped you please remember to Kudos me 😉

Tazz
0 Kudos
Reply
Highlighted
  • 3.82K
  • 174
  • 298
Forum Team
Forum Team
729 Views
Message 9 of 15
Flag for a moderator

Re: Bracknell Gig1 Stats

Hi,

 

Thanks for your post on our Community Forum!

 

Sorry to read that you've been having issues with your broadband service. Have you managed to get this resolved with our team or is it still on going? 

 

Drop us a response and either I, or one of my colleagues will be happy to pick it up for you

 

Kindest regards,

 

David_Bn

0 Kudos
Reply
Highlighted
  • 441
  • 11
  • 62
Fibre optic
717 Views
Message 10 of 15
Flag for a moderator

Re: Bracknell Gig1 Stats

Hi David

Nope it was dropping all night as shown in my graph here: https://www.thinkbroadband.com/broadband/monitoring/quality/share/9dca4ba9f5d4fb24a2995d1d663a438eef...

Downstream bonded channels
Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 411000000 12.099998 38.983261 QAM256 1
0 UNKNOWN 0
2 419000000 12.199997 38.983261 QAM256 2
3 427000000 11.400002 38.983261 QAM256 3
4 435000000 11.400002 38.983261 QAM256 4
5 443000000 11.599998 38.983261 QAM256 5
6 451000000 11.199997 38.983261 QAM256 6
7 459000000 10.800003 38.983261 QAM256 7
8 467000000 10.199997 38.983261 QAM256 8
9 475000000 10.300003 38.983261 QAM256 9
10 483000000 10.900002 38.983261 QAM256 10
11 491000000 10.599998 40.366287 QAM256 11
12 499000000 10.400002 38.983261 QAM256 12
13 507000000 10.900002 38.983261 QAM256 13
14 515000000 10.900002 38.983261 QAM256 14
15 523000000 11.099998 38.605377 QAM256 15
16 531000000 11.000000 40.366287 QAM256 16
17 539000000 10.500000 38.983261 QAM256 17
18 547000000 10.500000 40.366287 QAM256 18
19 555000000 10.699997 38.983261 QAM256 19
20 563000000 10.099998 38.983261 QAM256 20
21 571000000 10.199997 38.983261 QAM256 21
22 579000000 10.599998 38.983261 QAM256 22
23 587000000 10.300003 40.366287 QAM256 23
24 595000000 10.400002 40.946209 QAM256 24
25 603000000 9.800003 38.983261 QAM256 25
26 611000000 8.599998 38.983261 QAM256 26
27 619000000 9.300003 38.983261 QAM256 27
28 627000000 9.800003 38.605377 QAM256 28
29 635000000 9.699997 38.983261 QAM256 29
30 643000000 9.699997 38.605377 QAM256 30
31 651000000 9.099998 38.605377 QAM256 31


Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 0 7 0
0 NotLocked 0 0 0
2 Locked 1421888 9 0
3 Locked 1542837 17 0
4 Locked 1450087 9 0
5 Locked 1465937 15 0
6 Locked 1473732 21 0
7 Locked 1183661 19 0
8 Locked 1310946 25 0
9 Locked 1308079 34 0
10 Locked 1271063 27 0
11 Locked 1319732 32 0
12 Locked 1214606 42 0
13 Locked 1225325 57 0
14 Locked 1254373 60 0
15 Locked 1317295 56 0
16 Locked 1218050 69 0
17 Locked 1205344 75 0
18 Locked 1260534 80 0
19 Locked 1284845 93 0
20 Locked 1239713 140 0
21 Locked 1162843 101 0
22 Locked 1186345 115 0
23 Locked 1259434 155 0
24 Locked 1380327 152 0
25 Locked 1425797 187 0
26 Locked 1385974 225 0
27 Locked 1316458 207 0
28 Locked 1581888 254 0
29 Locked 1518305 248 0
30 Locked 1767144 271 0
31 Locked 488119879 264 0

Upstream bonded channels
Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1 46200000 23.520599 5120 KSym/sec 64QAM 3
2 39400000 23.770599 5120 KSym/sec 64QAM 4
3 53700000 24.270599 5120 KSym/sec 64QAM 2
4 60300000 24.270599 5120 KSym/sec 64QAM 1


Upstream bonded channels
Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1 US_TYPE_STDMA 0 0 1378 167
2 US_TYPE_STDMA 0 0 1378 167
3 US_TYPE_STDMA 0 0 1378 167
4 US_TYPE_STDMA 0 0 1378 167
----------------------------------------------------------
ThinkBroadband Quality Graph Gig1

If my post helped you please remember to Kudos me 😉

Tazz
0 Kudos
Reply