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nervex
02-09-2011, 01:12
Hi, I posted ages ago about some problems that I was having with my internet being intermittant.

That finally got solved after a lot of engineers and poking around with the cabinet. It has been perfect for over a month now.

Just yesterday (Wednesday) my neighbours got Virgin, and what a coincidence - one day later, my net has disconnected with an upstream power of 58.2/61

Right now it keeps dropping in and out and is very, very slow when it does connect. Its taken me ages just to get here. However this time I found the Event Log on the superhub, which is getting rapidly filled with these messages:


Lost MDD Timeout;
MDD message timeout;
SYNC Timing Synchronization failure - Failed to acquire FEC framing
SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
DHCP FAILED - Requested Info not supported
No Ranging Response received - T3 time-out
Unicast Ranging Received Abort Response - Re-initializing MAC

---------- Post added at 00:12 ---------- Previous post was at 00:11 ----------

+This is making me quite worried as I am due to be upgraded to 100mb next friday [sorry for double post, got to be quick - dont know how long it will stay connected this time]

thenry
02-09-2011, 01:25
your last thread > http://www.cableforum.co.uk/board/12/33678627-intermittant-cable.html

you need to get hold of Dan Bayliss the project manger to get it sorted ASAP. post up on the community addressing it to Dan Bayliss the project manager in the title.

In fact send an email to the CEO at VM,

neil.berkett@virginmedia.co.uk

state whats up and ask him to forward it to Dan Bayliss.

nervex
02-09-2011, 02:02
id like to post there immeddiatley if if will get me somewhere, however i have had to resort tousing my phone again as its completely dead right now. will have towait and see if it starts working again

---------- Post added at 01:02 ---------- Previous post was at 00:34 ----------

managed to stay connected long enough to send an email. Hope for a swifty response but usually not the case with these things. :/

thenry
02-09-2011, 02:16
VM's seniors are extremely good to work with. You should have your areas senior engineer at the cabinet tomorrow, you can slaughter my rep if nothing at all happens by means of a reply etc. ;)

nervex
02-09-2011, 02:26
Your confidence is inspiring. I hope I can join you with it at some time tomorrow!

I will get some sleep in the hope that it stabilizes by 9am as thats when I roll out of bed and have to start work (web developing from home without web is kinda hard!). :erm:

nervex
02-09-2011, 10:53
Looks like it was on and off throughout the night (I left TeamSpeak3 open with Auto Reconnect on so I could check it).

Looks to have come back on proper at 7 am (was playing up since 11.30), but the upstream power is 57.2 so I'm thinking it will continue to dropout at some point like it did previously

nervex
02-09-2011, 19:43
I got a call from the office saying that it was passed on to someone more technical.

After it came back on at 7am, the upstream slowly dropped back down, It got down to 51.7 I think (over several hours) but I just checked it again and its at 58.2.

I'll be surprised if it stays connected.

Peter_
02-09-2011, 19:49
Quite simple really, you need a technician.

nervex
02-09-2011, 19:59
Quite simple really, you need a technician.

Last time this happened, technicians couldn't do anything about it. Theres something wrong with the cabinet and I don't want this to recur.

Peter_
02-09-2011, 20:05
Last time this happened, technicians couldn't do anything about it. Theres something wrong with the cabinet and I don't want this to recur.
I guess due to the upstream saying 58.2 that when it is working you have 4 downstreams which means you are on a Motorola CMTS and that high a level is as high as it will show and it needs an engineer.

It may be the drop cable from your property that needs replacing or it needs raising to Networks for resolution.

Every single cabinet on the network are in the process of being replaced as well.

nervex
02-09-2011, 20:16
I guess due to the upstream saying 58.2 that when it is working you have 4 downstreams which means you are on a Motorola CMTS and that high a level is as high as it will show and it needs an engineer.

It may be the drop cable from your property that needs replacing or it needs raising to Networks for resolution.

Every single cabinet on the network are in the process of being replaced as well.

Apologies.. I'll add some context :)

The cabinet here is brand new. It's a new-build housing estate which isn't completed yet. So also the cables are brand new.

Previously, they have:
Replaced modem with superhub
Replaced internal cables
Replaced Isolater (twice i think?)
Replaced splitter
Checked levels at the cable point inside and outside the house (Luckily, at a time when it wasn't working).
Replaced tap-plate in the cabinet

They were about to replace the amplifier but came back after a while and said they'd re-configured it somehow (I don't know details) and it was fine for .. probably about 2 months.

I had about 7 visits last time checking everything, replacing equipment. It took network and a principle tech a couple of visits to the cabinet to get it looking anything like it should. The problem I have now is exactly the same as before, so please forgive me [edit: not] for wanting a simple visit which would probably be a waste of time..

Also, Last time the principle tech said someone else on the street was having problems so I am tempted to go and check with them.

Peter_
02-09-2011, 22:29
It would not be a simple visit if they were being asked to check and replace the drop cable but it does depend on the agent you get though.

nervex
02-09-2011, 23:10
It would not be a simple visit if they were being asked to check and replace the drop cable but it does depend on the agent you get though.

I just hope that I don't have to spend weeks starting from scratch with loads of engineers etc, I'd rather just type out the scenario here than go through all that hassle again. We covered most of the troubleshooting in a couple hours instead of several weeks worth of failed engineer visits etc.

Thanks for trying to help though :hyper:

Nedkelly
02-09-2011, 23:20
With the upstream getting high it could be noise .When your upstream gets high the snr gets lower so the modem has to shout over the noise .This can be cuased by bits of the network being old and reacting with each other or some has been doing a spot of DIY cable installing .The last few weeks we have had a couple of these caused but somone using 1 electrical chop blocks to join coax 1 he had terrible speeds and 2 he was putting noise on the network .Your cab may be new but it could be linked to a older part of the network sometimes these faults are not always there for us to find :mad:.We have to watch the network and wait then go out and sort it .

jb66
03-09-2011, 00:56
It could be all of those big faults......Orrrrrrrrr, your neighbour got put on the top powered tap and you got moved down

Sephiroth
03-09-2011, 13:15
I guess due to the upstream saying 58.2 that when it is working you have 4 downstreams which means you are on a Motorola CMTS and that high a level is as high as it will show and it needs an engineer.

It may be the drop cable from your property that needs replacing or it needs raising to Networks for resolution.

Every single cabinet on the network are in the process of being replaced as well.
I'm obviously not arguing with your recommendation.

But the Cisco UBR with the MC3GX60V line card also punts out 4 downstream channels.

Ignitionnet
03-09-2011, 13:33
With the upstream getting high it could be noise .When your upstream gets high the snr gets lower so the modem has to shout over the noise .This can be cuased by bits of the network being old and reacting with each other or some has been doing a spot of DIY cable installing .The last few weeks we have had a couple of these caused but somone using 1 electrical chop blocks to join coax 1 he had terrible speeds and 2 he was putting noise on the network .Your cab may be new but it could be linked to a older part of the network sometimes these faults are not always there for us to find :mad:.We have to watch the network and wait then go out and sort it .

Sure about this Ned?

Even with the SNR massacre in this area the upstream transmit power on my modem didn't budge, that was with SNR getting munted to levels where there were 50%+ uncorrectable FECs.

My first thought was that this guy was connected to two different service groups but the bouncing between 64QAM and 256QAM along with TDMA and ATDMA is probably just him being retuned from the DOCSIS 1.1 network to DOCSIS 3.

Shouldn't they be sending someone to do a sweep of the upstream network from his cabinet, and surely CARDIE should show problems with return path performance in terms of power adjustments and SNRs.

Pretty poor show to be honest.

nervex
03-09-2011, 15:16
If it helps to clear anything up to you guys, I do have 4 downstream channels that are usually fine. However during times of high upstream power, the downstream power usually sky-rockets.

Currently everything appears to be fine, downstream:
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power SNR Docsis/EuroDocsis locked
Locked QAM64 97 41712000 Kbits/sec 299000000 Hz 1.2 dBmV 34.3 dB Hybrid
Locked QAM64 98 41712000 Kbits/sec 307000000 Hz 1.0 dBmV 34.6 dB Hybrid
Locked QAM64 99 41712000 Kbits/sec 315000000 Hz 1.0 dBmV 33.8 dB Hybrid
Locked QAM64 100 41712000 Kbits/sec 323000000 Hz 0.7 dBmV 33.9 dB Hybrid



And upstream
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power
Locked ATDMA 5 20480 Kbits/sec 45800000 Hz 51.9 dBmV

Again, only posting this incase it helps clear anything up.

Peter_
03-09-2011, 15:55
I'm obviously not arguing with your recommendation.

But the Cisco UBR with the MC3GX60V line card also punts out 4 downstream channels.
According to Ignition only on 100Mb and only 2nd line deal with those calls so never seen one.

On 50Mb and below they have 3 downstreams.

Sephiroth
03-09-2011, 16:17
DS-1 DS-2 DS-3 DS-4
Frequency 443000000 435000000 451000000 459000000
Lock Status
(QAM Lock/FEC Sync/MPEG Lock) Y/Y/Y Y/Y/Y Y/Y/Y Y/Y/Y
Channel Id 170 169 171 172
Modulation 256QAM 256QAM 256QAM 256QAM
Symbol Rate
(Msym/sec) 6.952 6.952 6.952 6.952
:
:
Power Level
(dBmV) -2.29 -2.25 -2.13 -1.74
RxMER
(dB) 34.77 34.21 35.25 35.42
Correctable
Codewords 160292 943306 40820 21710
Uncorrectable
Codewords 876 312 295 294

RDNG-21. Is that Motorola or Cisco? A few weeks ago it was defo Cisco because I had three DS channels. Why would they make that a Motorola when the 10K2 is perfectly good for DOCSIS 3 es[ecially with the new line cards?

Peter_
03-09-2011, 16:20
DS-1 DS-2 DS-3 DS-4
Frequency 443000000 435000000 451000000 459000000
Lock Status
(QAM Lock/FEC Sync/MPEG Lock) Y/Y/Y Y/Y/Y Y/Y/Y Y/Y/Y
Channel Id 170 169 171 172
Modulation 256QAM 256QAM 256QAM 256QAM
Symbol Rate
(Msym/sec) 6.952 6.952 6.952 6.952
:
:
Power Level
(dBmV) -2.29 -2.25 -2.13 -1.74
RxMER
(dB) 34.77 34.21 35.25 35.42
Correctable
Codewords 160292 943306 40820 21710
Uncorrectable
Codewords 876 312 295 294

RDNG-21. Is that Motorola or Cisco? A few weeks ago it was defo Cisco because I had three DS channels. Why would they make that a Motorola when the 10K2 is perfectly good for DOCSIS 3 es[ecially with the new line cards?
Ignition says that Ciscos running 100Mb use 4 downstreams so as I have seen one I would not be sure.

If yours is the same CMTS then it will still be a Cisco unless Ignition is reading this and can set us right.

Most of the 10's have been upgraded to 12's, probably retrofitted.

Sephiroth
03-09-2011, 16:24
If it helps to clear anything up to you guys, I do have 4 downstream channels that are usually fine. However during times of high upstream power, the downstream power usually sky-rockets.

Currently everything appears to be fine, downstream:
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power SNR Docsis/EuroDocsis locked
Locked QAM64 97 41712000 Kbits/sec 299000000 Hz 1.2 dBmV 34.3 dB Hybrid
Locked QAM64 98 41712000 Kbits/sec 307000000 Hz 1.0 dBmV 34.6 dB Hybrid
Locked QAM64 99 41712000 Kbits/sec 315000000 Hz 1.0 dBmV 33.8 dB Hybrid
Locked QAM64 100 41712000 Kbits/sec 323000000 Hz 0.7 dBmV 33.9 dB Hybrid



And upstream
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power
Locked ATDMA 5 20480 Kbits/sec 45800000 Hz 51.9 dBmV

Again, only posting this incase it helps clear anything up.

So - it's broadening out. Usually upstream power rockets because there is an upstream impairment and the CMTS commands the modem to raise power to try and drive something sensible through.

Downstream power is beyond the control of the modem (it gets what it gets) and is also, for the purposes of this analysis, beyond the control of the CMTS. So, what's in between?

A malfunctioning amplifier, most likely.

Is your SNR always around the 33/34 mark? You are clearly in a poor quality infrastructure area being on 64QAM modulation to cope with that poor SNR. Where exactly are you? It might be that the whole plant in your area is clapped out and in need of replacement.

nervex
03-09-2011, 16:37
I am in Doncaster (DN2). I believe it that it does ocassionally swap to QAM256, and when it messes about the upstream does flick between TDMA and ATDMA which is making me think about what Ignit said. I seem to recall that previously the network & principle tech went to mess about with a load of nearby cabinets.

Not paid too much attention to the SNR but I would say its between 30-40 usually

Sephiroth
03-09-2011, 17:37
I suggest you hit the CONNECTION tab and note the HOST.

When it swaps to QAM256, do it again and compare the two.

Also paste the event log so we can correlate a modem reset (from their side) to the change. Your DS channels would change since the 64QAM channels are on a different frequency set.

Of course none of this'll get you very far other than knowing more about what's going on! Normally if what Igni says is happening to you, you'd go to a different CMTS.

nervex
03-09-2011, 17:48
Ok will do.

I get the host information from tools.virginmedia.com?

I have the event log from the hissy fit it threw the other night which has different CMTS MACs in it

I'll upload it in a min

Sephiroth
03-09-2011, 18:01
You can get the host information from the CONNECTION link at the top of this forum page.

nervex
03-09-2011, 18:01
Ok heres a picture of the log, obviously blanked out the MACs, except the last-2 digits of the CMTS. I have highlighted the rows in which it changes.

The red boxes - the CMTS MAC was just 00's.

http://iron-pulse.com/u/9231B16D_shlog.jpg




edit-thanks never saw that up there :)

Sephiroth
03-09-2011, 18:10
You don't have to blank out the CMTS addresses - only yours.

The different MAC addresses are not relevant. There are different servers and devices at the VM end handling different functions and those are the signatures you are seeing.

The Host name is the best indicator of changes to your service in the context we're examining.

nervex
03-09-2011, 18:14
Alright then. Will keep an eye on it. on host is donc9 at the moment.

nervex
09-09-2011, 23:25
Ok, so I got the 100mb upgrade today.

Typically after I complained last week it's been behaving quite well >.<

However, today while the engineer was here the upload was 58.2 before/as he arrived and around 10 minutes later it dropped back to 47. It went back up to 55 and right now it's dropped back down to 43!. Something crazy is going on there but all is working at the moment.


The engineer had some real issues trying to get any kind of speed test anywhere near 100mb. It was fluctuating wildly between 30mb and 70mb with upload staying constant at ~9mb/s

We ran the tcp optimizer which didn't do alot, but then he changed some network adaptor settings and tried again and got 91 mb/s at the paris server on speedtest.net

http://www.speedtest.net/result/1474627249.png - this is the best result I've gotten so far.

I can get 12 mb/s download by using a link-grabber program, about 4mb/s from steam (might try this again after midnight?) but only about 6-8mb/s when trying to download an ubuntu iso from Virgin. (http://ubuntu.virginmedia.com/releases/11.10/ubuntu-11.10-beta1-desktop-i386.iso)

nervex
10-09-2011, 01:37
So I tried steam again and its a little disappointing,


http://iron-pulse.com/u/0BA34175_steamb.jpg
- Ignore 0 bytes/sec at the top, this is because I hit pause.

The pic was taken after 2500 mb (8 minutes approx) and the red line indicates a level of around 6.8 MB/s.

qasdfdsaq
10-09-2011, 05:16
Virginmedia's download servers are frequently slow, Steam is often slow as well. Some days I can't get more than 15mb on steam. Nothing wrong with your connection.