Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: JamesK on August 14, 2013, 04:29:02 PM
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Hi All,
I've just come back from a 2 week holiday. While I was away I powered off the modem and router. Since powering up the modem and router on Saturday my connection speed has dropped from around 28-9mbps to 24-25mbps.
The BT availability checker has always said I should be able to get 31mbps. I would say that I'm about 950m from the cabinet. When Infinity was installed the BT engineer disabled all of the phone sockets in the house except the one used for the FTTC connection, as the socket I'm using seems to be wired separately to all the others. The modem is wall mounted and plugged directly into the socket next to it. The router (Asus RT-N66U) is about 8m away from the modem.
To try and find out more I've unlocked the modem and started logging the results continually. I've attached the first batch. The gaps in the reports are where the laptop I'm using to log results needed to reboot for windows updates, etc.
From the limited research I've done so far I've worked out the DSLAM is ECI, Interleaving is on, and I've got a fairly quiet line. Am I right in thinking that DLM has taken some action and reduced the line speed to 25mbps and enabled interleaving? I was under the impression that turning off modem & router while on holiday wouldn't have a negative impact on the line speed. Should this be something that corrects itself in the next few days provided the modem isn't power cycled?
Would really appreciate if people more knowledgeable than me on this could take a look at the output and tell me if the stats look ok, if there's an issue that needs to be looked at and generally explaining the stats to me!
Many Thanks in advance....
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Additional Stats attached...
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Hi James and welcome,
Just to say we're not ignoring you and that it looks suspiciously like your line has been capped at 25 mbps.
With an attainable rate of over 37 Mbps it seems you should do better but there's not a great deal of spare noise margin.
Let's wait for the real experts to have their tea !
Kind regards,
Walter
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Hi Walter,
Thanks for the update and the welcome :). I didn't think you were ignoring me, as I know pretty much everyone contributes to forums in their spare time... if they have any!
While I was away on holiday I received a text saying the following "dear customers. There has been a BT line fault, we will be back on tomorrow, we apologise for any Inconvenience". I didn't pay too much attention as I was away and the modem/router were all switched off. I did think the wording of the message was a little strange & expected an e-mail as well. However, it came from a mobile number starting +44 7538 629XXX. So I thought this was perhaps the mobile of a BT engineer attending the incident.
I too, felt that my line speed had been capped at 25mbps. But I wasn't sure if it was as a result of the fault and/or the modem being switched off.
Would it be worth power cycling the modem at this point? Or will DLM resync the modem automatically if it decides to make a change? Apart from powering the modem back up on Saturday morning the only downtime on the modem has been to unlock it in order to start getting the statistics from it.
I've attached 3 days of stats that have been collected and also the current stats for this evening.
Hope this helps... Cheers... James
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Hi James and welcome.
I very briefly wondered about capping, but I dont think so because the SNRm sits at around 6dB.
The bitloading in one of those graphs doesnt look too good in the 100-500 range which to me implies that there is something generating noise on those frequencies. With those bins not being fully loaded, it will have an impact on the sync speed... but then that doesnt explain why the router is reporting an attainable rate of 36212.... and now weve gone full circle
Looking at those stats... if it was an adsl2+ connection and looking at a DMTtool graph, i'd say it typically looks like the modem needs a reboot and resync, because its recovered from a bad sync.
It would be interesting to see the bit loading too at a fresh modem boot to see if those tones are still poorly loaded.
... and then as Im typing this, I notice your real SNR and the QLN data... and Im back to wondering what the heck is going on at tones 100-500... ???
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I've spent a lot of time this past few days looking through the forum posts and I did notice that my graphs of the bitloading for tones 100-500 looked strange compared to others.
There was a power brick for a Polycom conference phone fairly near the modem until earlier today. I thought it might be a cause of interference, as it's quite large. Is there anything in the house I could look out for which would be generating noise in the 100-500 tone area that could cause it? Or is it likely to be external to the house?
The service has been active for over a year now. For the first couple of months I had close to 30mbps. It then dropped down to around 24mbps for several weeks before slowly getting back up to around 28-29mbps.
The BT engineer who installed Infinity thought that it was odd the socket in the room I've got the modem (top floor of a 3 storey house) was wired to the grey box at the front of the house separately to all the other sockets, and there's lot of them! He said this was good as he could easily disconnect all the others.
I'll do a modem power off/on in a little while. I didn't want to do it in case it would make speed worse. I'll post new line stats shortly.
Cheers... James
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Powered off router and modem, and then all back on again. Attached are the updated current stats. I'm not seeing any difference. Would it be worth calling BT and asking for clarification on the fault I received a text message about?
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Your DS sync speed does indeed appear to have been capped/banded.
Any sync speed ending with 998, 999 or 00 confirms it has been banded.
Your US sync speed is not banded, as confirmed by the variable sync speeds & Interleaving depth of 1.
Along with the comments regarding your QLN & SNR graphs, your quite high DS Interleaving depth of 1771 also confirms your connection is/has been 'noisy' or it has recorded high error counts.
Lower down the Plink log, you will see data against INP & delay.
The lowest level of INP (Impulse Noise Protection) is usually 3.00 DS & o.oo US.
The lowest level of delay is usually 8.00 DS & 0.00 US.
DLM may attempt to increase sync speed & lower interleaving/delay levels if a few days of stability/low error counts are recorded, but isn't unknown for DLM to 'stick' for many days at a time, sometimes apparently indefinitely.
Finally, DS Bitswapping seems quite high(ish), suggesting that bitloading can be a little sporadic. i.e. sometimes some tones are unavailable, so bitloading is swapped around.
A 'quiet' connection would typically report around 12 bitswaps per minute during the daytime, increasing to around 20 or so overnight.
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Would it be worth me trying to raise a case with BT regarding this? I'm concerned whatever the fault was that I received a text about while on holiday could be the cause of any errors/noise on the line. Up until going on holiday the speeds had been stable for 10 months.
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Hi again James,
IMHO you will need a VERY STRONG determination if you are to attempt a resolution through BT India.
I suggest you try all you can yourself to investigate noise sources including all the old favourites such as faulty fluorescents, street lights, boiler thermostats etc. etc. etc.
When you are ready to talk to BT, prepare all the evidence from the wonderful Bald Eagle's facilities together with a brief history of what you have attempted.
Put all this in a PDF document and then "on-line chat" to India downloading the PDF immediately.
Cut & paste the chat as it proceeds into a separate document.
Record and add any other names / and engineers involved at all times.
If Openreach contact you by mobile record the phone number if available.
You may well have to jump through all the usual hoops of power-resetting modem, using the test socket with a filter etc. etc. but as soon as you can say you want your PDF reviewed by a level two desk person.
DON'T be fobbed off with having to wait 24 hours for the level two to ring you back.
IF and when you get to the stage of arranging an appointment insist it is a morning one and say you want a VDSL specialist.
You probably won't succeed the first time but patience is a virtue.
If you are offered to take a survey ensure it is full and frank & include your e-mail address.
One day BT may just wake up to the fact that VDSL maintenance requires very substantial and well trained resources.
You may well find that the BT subsidiary PlusNet (or any of the better smaller ISPs) handle things more easily for you.
Most waste less of your time with delays and obfuscation but all rely on the splendid experience of dedicated Openreach technicians such as our excellent BlackSheep.
The very best of good luck !
Kind regards,
Walter
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Many Thanks for the advice on ways I need to deal with BT India. I've also dropped a message onto the BT Community Forum as I know the mods there can sometimes fast-track stuff if they see it as an issue.
There's not a lot in the house that has changed in the last few weeks that could've caused an increase in noise. I know I can't rule out something starting to go wrong, such as the thermostat on the boiler. The house itself is only just over 10 years old.
I've taken the BT socket off the wall, and all looks good with the wiring there (only 2 green wires connected). I've also replaced the RJ11 lead for a decent CAT6 one from e-Bay of the shortest length I could get to see if that helps as well.
In the meantime I'll keep logging the connection statistics.
However, I still think that whatever fault occurred while I was on holiday has something to do with the loss of speed I'm now experiencing. As well as being on a higher speed before I went away, the ping rate was also always a lot lower whenever I did a test on speedtest.net, which would tie up with interleaving now being on as well.
Best Regards... James
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I've taken the BT socket off the wall, and all looks good with the wiring there (only 2 green wires connected).
:hmm: If possible a picture or two, attached to a post to this thread or made accessible to view elsewhere, will allow us to examine what you have seen.
The socket to which you refer is an NTE5/A? :-\ (Example image (http://www.kitz.co.uk/adsl/socket.htm) at the top of the page.)
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This is the socket... I didn't take any pictures inside it though...
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fimg.tapatalk.com%2Fd%2F13%2F08%2F18%2Fusasypuj.jpg&hash=feee84e79ba2f17071f190c4865922cdb5853e4e)
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Thank you. So that confirms an NTE5/A plus SSFP combination is present.
I think we can therefore rule out any problems in that area.
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@ James,
Although the green pair indicates (Normally it's the blue pair) that the NTE5 is not directly connected to the drop wire, but that in itself doesn't usually cause a difficulty.
If you can get to the junction box where the drop wire is terminated it would be worth checking the crimps and removing the cobwebs.
HOWEVER if you do touch the wires be very careful not to snap any corroded ones, unless you have found some crimps from somewhere.
Kind regards,
Walter
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As the Cat 6 shorter length RJ11 lead had the effect of lowering my SNR, I replaced it with the original Huawei supplied RJ11 lead. As I left the modem powered off for 40 mins I took a photo inside the socket. I didn't realise there was another socket previously connected. The OR engineer must've disconnected it when I told him I only wanted the one master socket to be live.
I'm going to take a look at the grey box on the front of the house tomorrow.
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Ah ha. That shows there is at least one other socket -- now no longer operating -- somewhere in the house.
Hopefully the contents of the external grey box will just show the other end of that white internal CW1308 cable joined to the service cable.
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I've never known a house to have so many phone sockets. There's one in every room, except bathrooms. So about 7 in total. It took the OR engineer a while to figure out how they were all connected.
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This morning I removed the grey box outside the house. The cabling was much more messy than I was expecting, so did my best to tidy it up before taking photos. I've put together a crude diagram of how everything was connected in case the photos still aren't clear (click all the images to enlarge them)
Cable 1 goes to the master socket where the modem is connected, the OR engineer taped it to the BT drop cable. Cable 2 feeds most of the other phone sockets in the house which are now disconnected.
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fi74.photobucket.com%2Falbums%2Fi276%2FJamesK1975%2FBT%2520Cabling%2Fth_BTCabling.jpg&hash=127b7947a5de4e2fe1e2914bc91ca3d9f9bf5a08) (http://s74.photobucket.com/user/JamesK1975/media/BT%20Cabling/BTCabling.jpg.html)
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fi74.photobucket.com%2Falbums%2Fi276%2FJamesK1975%2FBT%2520Cabling%2Fth_2013-08-19113416.jpg&hash=98b99075b4cdaa14e2ad0957f9172e748af388a8) (http://s74.photobucket.com/user/JamesK1975/media/BT%20Cabling/2013-08-19113416.jpg.html) (https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fi74.photobucket.com%2Falbums%2Fi276%2FJamesK1975%2FBT%2520Cabling%2Fth_2013-08-19113436.jpg&hash=aa27984b1e51fa4bf1bb2186274bc4dc8d240582) (http://s74.photobucket.com/user/JamesK1975/media/BT%20Cabling/2013-08-19113436.jpg.html) (https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fi74.photobucket.com%2Falbums%2Fi276%2FJamesK1975%2FBT%2520Cabling%2Fth_2013-08-19113601.jpg&hash=ca76465341368e0aa9706c82669360c9a2a52e2d) (http://s74.photobucket.com/user/JamesK1975/media/BT%20Cabling/2013-08-19113601.jpg.html)
I wasn't expecting the BT drop cable to have so many cables contained within it. Is it normal for there to be several white cables? I was expecting all the cables to be uniquely identifiable.
I was surprised to see the blue cables between cable 1 and 2 connected together. However, thinking back I'm sure the OR engineer thought I had more knowledge of BT cabling than I actually did. When he was here I was busy crimping CAT6 ethernet cables and punching down cables into ethernet wall plates. He did make a comment that he'd wired cable 2 up in such a way that if I wanted to re-instate the other phone sockets I'd just have to move specific cables across outside. As we'd only recently moved in, and the house was in chaos I didn't pay too much attention to what he was trying to show me outside the house.
Why are the white/orange and orange/white cables from Cable 1 connected to the BT drop cable? They aren't connected to anything in the master socket in the house. If they aren't needed I was surprised the OR engineer didn't disconnect them. The remainder of the cables in the BT drop cable aren't connected to anything (3 x white, 1, Green, 1 x Grey, 1 x Brown)
Does all the cabling look ok? Is there anything I should do to tidy it up or improve things?
Many Thanks... James
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Hi James,
It looks as if you have a 10 pr feed into your property.
I'd guess at one stage more than one line was active and hence the blue pairs would have gone somewhere else in your birds-nest !
Assuming your connected green pair doesn't go anywhere else and not "daisy-chained" into any other sockets, then you have a reasonable configuration.
A simple test can be done by taking a corded phone around every socket to check there is no dial tone.
Probably only as a cosmetic exercise and assuming you definitely only have one phone number active, I might be tempted to separate the blue pairs by cutting away those two crimps.
If ever you need another live socket ensure that it is connected to the standard bottom half of the master socket front plate.
The grey box is called a BT66 box.
Kind regards,
Walter
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Thanks Walter.
The OR engineer mentioned that he thought a second phone line may have been active at some point in the past. There's definitely only one number active.
Would it not also be beneficial to cut the orange and white wire crimps off as well? These aren't connected in the master socket. Is it possible these unused lines could be causing noise on the active line? Attached picture to show wires I'd cut.
Is there anything else I should do inside the BT66 box to ensure any noise is kept to a minimum? Should the unused wires be bundled together with electrical tape?
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Hi again James,
I couldn't see clearly enough where the orange pair was connected but if you're sure that there aren't any adjacent houses / flats using that pair you could cut the orange ones as well.
I've seen some tight-twist individual pairs but then just push them out of the way. You don't want to be creating a transformer effect.
Perhaps BS can comment, but unless there are horrendous amounts of REIN about I suggest it should not make too much difference provided every unused wire is definitely open cct.
Kind regards,
Walter
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A few comments from The Cattery . . .
It is clear that you are provided with an underground feed, so you do not have an aerial 'drop cable' but a service feed. The service feed, the black cable, is actually a five pair cable (Walter has counted the wires but has failed to divide the result by two!) and it does appear that there were two separate lines installed at some time in the past. Regarding the ten wires in the service feed cable. Yes, five coloured wires and five white wires is quite correct. If you could see under the sheath you would discover that each coloured wire is twisted with one particular white wire, making a distinct pair. Hence it is important that a coloured wire is used with its corresponding white wire. Failure to do so results in a split pair (often referred to a split legs) which will be the source of poor xDSL performance of the circuit (and possible 'overhearing' with the telephony circuit).
Your proposal to remove the two pairs of crimps (linking the blue pairs of cables 1 & 2 and linking the orange pair of cable 1 to the orange/white pair of the service feed cable) makes perfect sense.
There is one thing that is not obvious to me. Behind the NTE5/A are two white CW1308 specification cables. One of them definitely carries the incoming pair from the service cable via its green pair. I assumed that the second white cable behind the NTE5/A was connected to the lower front faceplate and was the feed to the other extension sockets in the house. If my assumption is correct, then the second cable visible outside is not the second cable seen behind the NTE5/A! Possibly the second white CW1308 specification cable seen outside runs to another master socket somewhere in the house, from the time when a second line was also operative?
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Thanks for all the feedback on the wiring. It certainly helps me to have a good understanding of how everything is connected.
Cable 2 in the diagram goes directly to the original master socket located in the kitchen on the ground floor of the house. This is only about a metre from where the service cable is presented on the external wall. Most other extensions are wired off that master socket.
When the OR engineer arrived I said that I definitely didn't want the modem and router to be installed in the kitchen, and if possible wanted them to be installed on the top floor where a socket was present.
If memory serves, there was some confusion as the socket where the modem is connected now just looked like an extension socket, the same as the other rooms (except kitchen) and not a master socket. The OR engineer said the wiring suggested a 2nd line had been installed at one point, and that socket would've been a master socket for that line. Strangely one of the extensions coming the Cable 2/Kitchen master socket did have an NTE5/A faceplate on it. He quickly confirmed it was just an extension and had never been a master. I think the engineer came to the same conclusion as me that someone had been home bodging the wiring.
The other cable behind the NTE5/A in the picture will be connecting another phone extension. My guess will be the phone socket in the bedroom on the same top floor as this socket.
I felt it would be worthwhile to disconnect any wires not needed. Last night when I opened up the NTE5/A to take a picture I tidied the wiring up a bit so the photo would make sense. When I reconnected the modem picked up the D3 band for the first time (albeit with very high attenuation!). Stats attached. I wasn't sure if my wiring tidying had reduced noise somehow. I guess I could be wrong and it's a coincidence.
I'll disconnect the un-needed wires in the BT66 box tomorrow.
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Hmmm.
Your attainable rate has decreased & your Hlog graph now doesn't look quite right - a small dip in the D1 band along with a slightly wider gap in D1 bitloading & a spike in the D3 Hlog band.
D3 still looks too high an attenuation level to actually use any of it though.
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Any suggestions on what I should do next with this? I'd had no problems at all until the unexplained BT fault I received a text message about while on holiday.
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Would there be any benefit in having the modem connected to the master socket which is about a metre from where the service feed is presented and then running CAT5/6 ethernet to the router location? Probably about 15/20m from the service feed presentation point.
Would reducing the amount of CW1308 cable to a minimum provide connection speed benefits? Or is the 15/20m of CW1308 currently running to near the router from the service feed point not going to be the major cause of speed issues?
I'm only talking hypothetically here as it would require re-wiring the sockets again, and would probably be a total nightmare getting ethernet chased down to where I need it.
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Would there be any benefit in having the modem connected to the master socket which is about a metre from where the service feed is presented and then running CAT5/6 ethernet to the router location? Probably about 15/20m from the service feed presentation point.
Quite honestly, it will probably not be worth the effort.
Would reducing the amount of CW1308 cable to a minimum provide connection speed benefits?
Highly unlikely.
Or is the 15/20m of CW1308 currently running to near the router from the service feed point not going to be the major cause of speed issues?
The current configuration looks good enough, to me. :)
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I decided to leave my connection for a while, and sourced a new ECI modem from eBay in the hope that matching the kit would help matters. In the time it's been connected I had two DLM forced resyncs on the line. These had the effect of reducing the profile to 23.5mb and now to 19.36mb.
At this point I documented everything I had and contacted BT. This was the most painful experience ever. They insisted the HomeHub was re-connected, the modem re-set. They wanted me to re-run the BT speedtest. Explaining that the profile being set to 19mbps would mean I would not see an increase didn't seem to register. I eventually gave up on the first agent and tried again. The second person was slightly more helpful and has agreed there's an issue. He was going to raise it with the "Network Fault Specialist" team, and I've received some e-mails acknowledging that a fault has been raised.
When doing the tests for BT I used the opportunity to re-connect the HG612 modem so I can start getting stats again. Attached are the latest.
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the final two are attached.
The agent who I spoke said the following about the nature of the fault:
"A hard network fault has been found and so this case will be sent to suppl"
Didn't make a lot of sense to me.
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Your latest unfortunate experience is due to you being a subscriber to a Beattie Retail service. Her 'front line, level 1, customer support staff' are nothing but script reading numpties. :-X
Regarding the statement "A hard network fault has been found and so this case will be sent to suppl", I interpret its meanning as try as hard as they can, they cannot deny that there is a problem with your service. Accordingly they have passed their findings to either Beattie Wholesale or Openreach for investigation and, thus, hope to have 'washed their hands of the problem'. :-\
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Hi All,
I finally had a visit from BT Openreach yesterday. I really couldn't fault the guy that turned up, he spent over 2 hours with me trying different things. He started by doing a line test from my master socket on the top floor. This showed no errors on the line and said all the figures coming back showed no faults. He then got DLM reset. This had the immediate impact of bumping the speed back up to 31mbps, so I was happy.
He then decided to have a look at the service cable, and do some tests on it. He said it showed a slight 'dip' about 15m from the house. With that he found the distribution point in the pavement and pulled all that out. He straight away found a load of cabling trapped in the side of the clamshell type casing. He said the jelly crimp for my line wasn't in the best condition so he replaced that for me. He then checked the speed directly from the the grey box and found the speed was 44mbps.
On re-connecting my master socket the speed had increased to about 32mbps. So I was even happier. However, he wasn't done. Next he wanted to see how fast the original master socket performed on the ground floor in the kitchen. We were getting 38mbps from that socket. I was really surprised. As it's not practical to have a router in the kitchen we tried leaving the modem there and using Devolo 500mbps Homeplugs to link the modem and router together. While this worked, the speed for some reason wasn't great (24/25mbps). I'm sure it's because the mains wiring on the ground floor of my house is on a different circuit to the middle and top floors.
So reluctantly we had to re-connect the master socket upstairs in the house. He was very surprised I was getting around 6mbps speed loss on that run of cable from the front of the house up to the master socket in the office. Unfortunately I didn't get a chance to grab any modem stats while it was running in the kitchen, but the engineer said he thought the reason the bins weren't more loaded in the range 100-500 tone range was because of the house cabling going up to the office.
He recommended if possible in the future to use the master socket in the kitchen. So I'll probably need to find a way of running some ethernet into the kitchen, which is do-able.
My only concern was that with the all connecting of different kit to the service line the active pair has got really short. I don't actually think I could cut off the existing jelly crimps and get new ones on the cable without cutting away some of the black jacket protecting all of the wires in that service feed.
Would I be better off asking BT to come back out and swap over the active pair on the service feed?
Any thoughts on anything I can do to find out what could be causing such a large loss on a relatively small run of cabling in the house?
Cheers... James
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he spent over 2 hours with me trying different things.. /snip/.. We were getting 38mbps from that socket
Excellent ;D
but the engineer said he thought the reason the bins weren't more loaded in the range 100-500 tone range was
Which tells me that you got a damn decent engineer, not all engineers are even aware of bitloading. The guy I got yesterday was fascinated with DSLstats and wished that BT issued them with something similar. Yes I know they can get figures on the JDSU, but its hard to see things like bitloading on the tiny screen.
Would I be better off asking BT to come back out and swap over the active pair on the service feed
iirc your wiring was quite complicated, so I'd need to go back and re-read to make sure Im speaking correctly... but.....
if possible in the future to use the master socket in the kitchen
what happens if you just connect a cat5 run laid losely over the carpet etc, just as a test.. if the results are much better.. then you know its worth laying properly.
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I definitely consider myself lucky with the engineer I got.
The problem I've got is that the service feed outside the house now has hardly any cable for me to attach a jelly crimp to. Where the engineer was playing around so much with different things he cut the cable and jelly crimped several times progressively making it shorter.
So if I cut off the existing jelly crimp to crimp the other wire coming out of the house (coming from the master socket in the kitchen) I don't think there'll be enough cable to attach the new jelly crimp to.... unless I cut away some of the black sheathing around the service cable.
There are plenty of other wires coming out of the service cable itself (as you'll see in my previous pictures), but obviously they won't be connected to anything in the distribution point. So wasn't sure what to do really.
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My bug-bear !!! I always extend the 'active pair' if it's getting down to the cable butt. It only takes seconds. Equally, removing the outer cable-sheathing takes literally seconds to achieve, thus ensuring what you are calling the 'active pair' (commonly known as the 'feed'), is sufficient in length.
As you aren't supposed to be messing with this side of the network ..........a) I wouldn't request OR return to put your circuit onto another spare pair of wires in the black cable, and b) They wouldn't do that anyway, they'd just carry out the action/s I suggested at the start.
If you're hell-bent on making the kitchen as the master socket, then could you not cut the pair further up on the existing wire, feeding the upstairs master socket ?? Hard to put across in words, but instead of cutting it at the crimps like you say, cut it nearer the butt of the cable going to the socket upstairs and then you'll have enough to patch through to the 2 wires feeding the socket in the kitchen. It means you'll have 2 crimps on each wire (4 in total), but you'll be able to achieve what you want.