Help Interpreting ADSL2+ Results

[Ardua]

I have just e-mailed Support with a BT Speedtest showing a downstream speed of 527Kbps on an ADSL2+ service with an 7150 IP profile. My router disconnected itself from the internet at 02.54 this morning to prevent the ISP from initiating a disconnection!  There was also a loss of DSL synchronization at 4.30pm yesterday which resulted in an IP fall from 8000 to 7150. For most of the day, I have had good speeds:

Today 18:52   5929 kbps (741kB/s)   761 kbps (95.1kB/s)   
Today 16:16   6926 kbps (866kB/s)   774 kbps (96.8kB/s)   
Today 13:20   6930 kbps (866kB/s)   774 kbps (96.8kB/s)   
Today 12:02   7013 kbps (877kB/s)   765 kbps (95.6kB/s)   
Today 09:58   6963 kbps (870kB/s)   773 kbps (96.6kB/s)   
Today 07:37   6927 kbps (866kB/s)   773 kbps (96.6kB/s)   

My router DSL overview shows the following:

DSL Information

Overview
DSL


Receive Direction   Send Direction
Max. DSLAM throughput   kbit/s   24384   1280
Min. DSLAM throughput   kbit/s   160   32
Attainable throughput   kbit/s   8865   916
Current throughput   kbit/s   8865   915
         
Latency      1 ms   1 ms
Bitswap      on   on
Seamless Rate Adaptation      off   off
Impulse Noise Protection (INP)      0.0   0.0
Energy-saving Mode L2   NA   -   -
         
Signal-to-noise ratio   dB   15   7
Line attenuation   dB   16   6
Power Reduction   dB   0   0
Carrier record      A43   A43

Seconds With   Remediable Errors (FEC)   Not Remediable Errors (CRC)
Errors (ES)   Many
Errors (SES)   per
Minute   Last
15 minutes   per
Minute   Last
15 minutes
FRITZ!Box   144   0   0.2   0   0.09   1
DSL central exchange   13   5   0   0   0.14   3

Thanks.

[Rik]

My router disconnected itself from the internet at 02.54 this morning to prevent the ISP from initiating a disconnection!

Not quite sure what you mean by that?

The noise margin suggests that the line has been very unstable, resulting in DLM kicking in, either with a banded profile or an increased target margin. What else is connected to the line, and how is the router connected, ie master socket, hard-wired socket or trailing extension lead?

[Ardua]

Sorry Rik - been a bit busy lately. The router disconnect is a daily event which can be scheduled for a specific hour but cannot be turned off. (it's a German thing!) I am not sure what the message means: fortunately, the brief 'disconnect' does not appear to result in a loss of synchronization. After a week, my router stats remain broadly as they were a week ago with a BT Speedtest profile of 7150/915 and downloads bordering on 7000/720. LA and SNr downstream are 16 and 14, upstream 6 and 7. The router maintains a daily log and LA and SNr are broadly flat lined. I have scoured the house with a SW radio and the loudest interference that I can get is about 6 inches away from the LCD clock on the cooker. Simon has been extremely helpful but I can get nowhere near the 14 to 18Mbps service predicted by Kitz and other websites. I got up to a profile of 8000 with a loan router using the test socket but no further. My line stats were broadly as above. At least my line is now stable.

[Rik]

Forget the predictions, I'm afraid they look at line length, not quality. The d/s noise margin is knocking your speed by a couple of meg. You need to use a MW radio, not SW, as that's the band that ADSL works in.

What router is it? It seems an odd thing to force a reset.

[Ardua]

I was using a radio with a frequency of 610. I read somewhere that the optimum is 612. The router is a Fritz!Box.

[Rik]

We always recommend MW, Wiki quotes

With standard ADSL (annex A), the band from 26.000 kHz to 137.825 kHz is used for upstream communication, while 138 kHz – 1104 kHz is used for downstream communication.

.

As to the router, if you got better results from IDNet's test, I'd strongly suggest a change of make/model. Once the line is stable, you could try and get the target noise margin reduced.

[Ardua]

I have been away for a week so I turned off everything electrical in the house that I could. On my return today, router stats remain unchanged and apart from one BT -initiated disconnection, my connection has remained solid with an IP of 7150. Last weekend, I ran another BT 'quiet line' test from the test socket. It was a bit like a full hearing test: after listening for a while, I thought that I could hear some crackling on the line in addition to the slight hum. I spoke to my phone provider who said that they would run line a line test: I got an e-mail back not explaining what - if anything - had been done, but saying that everything was fine. The next line of the e-mail suggested an engineer visit at £99 +VAT +costs. If my line tested OK - then why suggest an engineer visit? This does seem to be an area that requires some regulation. If I take my car in for servicing, the garage usually reads the on-board computer and runs a series of diagnostic tests. If anything is found, then a course of action is proposed and agreed. As far as telecom faults are concerned, the onus seems to be on the end user to prove that there is a fault in order to avoid payment. Thoughts/comments.

[Rik]

The trouble is that so many ADSL faults are intermittent and so few BT engineers are really good at ADSL.

[Lance]

The next line of the e-mail suggested an engineer visit at £99 +VAT +costs. If my line tested OK - then why suggest an engineer visit?

And unfortunately the line tests can't pick up every fault.

[Technical Ben]

That and well, there is nothing wrong with listing all possible checks, even if some are very rarely used.
[edit]
Oh, and if the router is powering down/disconnecting at night, would this not upset the exchange equipment?

[Ardua]

Thanks guys. I am not sure where any of this gets me. My routerstats are stable which suggests to me that any line interference is constant. If I decide to go down the £120 route (at my risk), what objective evidence will I be given that the testing was carried out properly. For example, will I get a printout of the results against agreed standards that I can discuss with Support?

I could though take a more pragmatic view and wait for FTTC. My present broadband downstream speed is at least constant at 7MBps on a 7150 IP - albeit, 50% of what every broadband service checker says it should be. Synch now seems to be stable and I do not get the congestion that I was getting with ADSL Max. Moreover, on ADSL2+, I get a little more for my money than I got with Max.

I am not annoyed - just puzzled. The whole broadband business seems to operate in a World of 'smoke and mirrors'..

PS For Ben. I have spoken to the router manufacturer and the daily disconnect will not result in any loss of synchronization and it is standard on routers used in Germany. Most certainly, the detailed router log which is e-mailed to me daily has not shown any change in connection speed which sits at 8445/923. The router feature cannot be turned off  - but I can select when it happens (6am to 7am).

[Rik]

The system was changed recently to limit an ISP's ability to test. All they can do now is obtain a pass or fail. BT seem to be unanswerable to anyone, unfortunately.

[Ardua]

Thanks Rik. I have just read CBailey's post re his connection problems and if OR hasn't found any issues with his line then I haven't a hope of them doing so with mine. I probably would have better odds of keeping my money if I put £120 on a horse in today's Grand National! Surely, this is something that the ISPs need to take up with OFCOM. The good news is that I have just read in my local paper that WMMAL is now 'firmly' on the programme for fibre.

[Rik]

Sadly, Ofcom is more likely to side with BT than either the ISPs or the consumers.

[Ardua]

Now I am confused. My DECT phone is double filtered. Ten minutes ago, the DECT phone rang as I was sitting by my computer. I noticed that the DSL light on the router was flashing and then I had an internet disconnect. The router has re-synchronized at a slightly lower speed. My computer is connected to a wired LAN. Clearly, the phone ringing has caused the disconnect. What do I read into this and what is the best way to solve the problem? I have an I-Plate fitted and the phone is on an extension circuit.

[Steve]

It's difficult to be specific, classically it's caused by poor or faulty filters however it's a process of elimination. Connect the router with a good filter to the test socket and an ordinary phone if you've got one and see if it still happens. That should eliminate the DECT phone and the extension as a possible cause. If it still happens swap the router if you can and if still no cure I think that eliminates your side of the master socket as the cause and then it's on to support to look at possible line faults.

[Ardua]

Thanks Steve. I think that is back to basics. I will connect the router (again) to the test socket and see what happens.

[Ardua]

A further question if I may. I have decided to bite the bullet and buy an ADSLNation NTE 5 Master Faceplate. I will then connect my router directly to the ADSL unfiltered faceplate socket. Regarding my phones, I have 2 options. One, I could leave the phone extensions disconnected as my router has built in DECT. Two, I could reconnect the extensions which is what I would prefer to do as we are hoping to move in the next year - market permitting. In this case, the jury seems to be undecided re connecting Wire 3 (the bell wire).

If I do connect my existing phone extensions without ADSL, can these still be a source of interference or has the NTE5 effectively separated the two circuits?

Grateful for any thoughts. Thanks.

[Steve]

I would connect the extensions to the filtered faceplate but leave off the bell wire as it's not required for to day's phones.

[Ardua]

Thanks again Steve. Having had no problems before with a phone-initiated broadband disconnect, I have just come back in to find that it has happened again - a second event in a 16 hour period. My router log shows an incoming call at 1030am this morning followed by an immediate disconnect. Much to my surprise the re-connection was at an increased speed 8.7Mbps compared to 8.2Mbps last night (both with an IP of 7150).

[Rik]

Could be a wiring fault. Does it happen if the phone isn't connected to the line?

[Ardua]

To be honest Rik, I do not know. I hope to install the faceplate tomorrow which will take most of the current wiring, filters and the DECT base station out of play. It is just odd that after a month on ADSL2+, the phone-related disconnects have started to occur when I haven't touched the extension wiring. That said, I appreciate that saying 'everything was fine until teatime yesterday' is a pretty meaningless statement.

[Glenn]

There is a good chance, if it is a wiring fault, that it is on BT's side of the face plate or external wiring.

[Ardua]

My NTE5 faceplate arrived today and I have just installed it. Pin 4 had 2 wires connected to it which I understand do nothing so I have left them unconnected as I have with Pin 3. All phone extensions checked and they are working. I have connected my Fritz!box to the ADSL output on the faceplate using the bespoke Cat5 splitter lead supplied with the router. Just prior to the move a BT Speedtest gave the following results: IP7150/924, Connected Rate 9139/924, Downstream 7885 and Upstream 739. My latest BT Speedtest shows an IP7150/1078, Connected Rate 11699/1078, Downstream 7452/850. My current Downstream LA and SNR are 14/14 and Upstream LA and SNR 7/6. Clearly, there has been an improvement in the connection rate. Apart from being patient, do I need to do anything more?

[Steve]

I guess see if it remains stable, the downstream margin is high but that should come down if the connection remains stable, if doesn't and the connection is stable support may be able to get it reset for you.

[Ardua]

Thanks again for all the advice. I read somewhere that ADSL is more of an 'art' rather than a 'science'. Short of digging a 1Km trench to my exchange and putting in a new line, I think that I have now done everything possible to rule out line problems in my home. To complete my ADSL education, could any of the 'wise men' on this forum help me understand this page from my router log? Sadly, the only explanation that I can find is in German. I really should have tried harder at school.

This snapshot is taken with all DECT phones turned off and a single corded extension phone. With a DECT phone on, there is no noticeable difference in the analysis.

[Steve]

There's a better explanation than I can give.

http://forum.zensupport.co.uk/25732/25722/permalink/ShowThread.aspx#25722

[Polchraine]

Thanks again for all the advice. I read somewhere that ADSL is more of an 'art' rather than a 'science'. Short of digging a 1Km trench to my exchange and putting in a new line, I think that I have now done everything possible to rule out line problems in my home. To complete my ADSL education, could any of the 'wise men' on this forum help me understand this page from my router log? Sadly, the only explanation that I can find is in German. I really should have tried harder at school.

This snapshot is taken with all DECT phones turned off and a single corded extension phone. With a DECT phone on, there is no noticeable difference in the analysis.

That is quite a nice fairly clean plot.   It does not show any significant problems - an occasional Bin is missing but that happens and the dip around 900 -1100 kHz is common as there are a lot of MW radio stations in that area.

[Ardua]

Wow - I am learning a lot about something which a month ago was nothing more to me than 'plug and play'. My IP has just jumped from 7150 to 10000 - what a difference a day and filtered faceplate makes. With the higher connection speed I am seeing more router errors which I understand is normal. That said, I do not understand the difference between router and DSL exchange errors - the latter have increased significantly. Thanks again to everyone on this forum who gives up their time to help IT-challenged guys such as me.

[Ardua]

Me again - sorry guys. I now have a pretty stable connection rate of 11800/1078 - IP10000. That said, downstream CRC errors remain high. For convenience, I am still using a new Gigaset pair of DECT phones connected to an extension phone socket. As stated earlier, I now have a filtered NTE5 faceplate so I have removed all the dangly ADSL filters. Over the past week - with both a non-filtered and a filtered faceplate - I noticed that incoming PSTN calls were resulting in a short internet disconnect. One occurred 30 minutes ago when I was not at home. The only effect was a resync at a slightly increased rate. I imagine that the answer is that the incoming call is causing additional line noise which, in turn, is causing a higher CRC rate and a temporary loss of DSL sync or is there a more likely reason for what is happening. What, if anything, can I do about it?

[Glenn]

Get support & BT to take a look at the line, can the problem be reproduced by calling your number?

[Steve]

Have you discussed the problem with support as to me you've done all you can at your end. I wonder if a line fault is worth investigation?

[Ardua]

Thanks. I will give Support a call. My router logs all incoming calls as it is also a DECT base station. The timing of the incoming call and the DSL de-synch are exact match. I have also seen the DSL synch light flashing whilst the ring was ringing.

[Ardua]

I spoke to Support and they were keen for me to go through the whole Test Socket malarkey again. I thought about it some more and then I found some advice on Whirlpool.Au about noise on long and poor phone lines. The consensus seemed to be fit a 'double ADSL filter' to the phone line even where a filtered faceplate is already fitted. I did a 'before and after' test and it seems to be working. I post this in the hope that it might help others in a similar situation to me.

[Steve]

Thanks for the reply Ardua, Whirpool is a very good and active broadband forum.

[Rik]

They make good washing machines too.

[Ardua]

A long weekend and three disconnections later, IP is now down from 10K to 8K. No apparent reason for the disconnects. Different times of the day: no apparent loss of SNR, not related to incoming phone calls. A further disconnect this afternoon resulted in an increase in connection speed from 9942 to 12820 with a reduction in SNR from 17 to 11. The first time that downstream SNR has been below 15 in the 3 weeks that I have owned this particular router.

I contacted Support who proffered the view that I might have router/line incompatibility - a first for me (I am on my 3rd new router). I am about to run a Fritzbox router diagnostics test and send the results to AVM for review once I know what parameters the test records. I have disconnected just about everything short of the kitchen sink to rule out RF interference.

Grateful for any thoughts on what might be going on.

[Rik]

I think we've had a case of a Fritzbox problem before with ADSL2+, but I can't put my finger on the thread right now. Certainly, some routers are incompatible with some MSANs.

[Ardua]

It is time to close out this thread with an update which may be of help to others who experience similar issues in the future. Sixty Seven days on from my upgrade to ADSL2+, I now seem (tempting fate/fingers crossed) to have a stable connection with a static downstream SNR of 7 with a connection rate of 12/1.1Mbps IP 10000. I can now claim 9 days of solid connection with a very low CRC rate - both upstream and downstream: this is 3 times better than I could claim 10 days ago! Yesterday, Support connected me to say that they have done some further research and they could limit my upstream to 800 or 448. However, collectively we have decided that as my line appears to more stable it is probably best to leave things as they are even if the downstream is less than predicted. It will be interesting to see what happens after my Exchange's PEW next week. If I experience frequent losses of synchronization in the future, then I have 3 options: (1) Update my router with beta firmware which has quote an improved ADSL pump unquote; (2) wait for the planned firmware formal release in Jun/Jul or (3) ask IDNet to limit my upstream and then see what happens. Come what may, I grateful to Support for the time and effort that has gone into addressing my concerns.

If I have learnt one thing about an ADSL upgrade it is this. Treat it like gardening - prepare the ground first. Put in a filtered faceplate and find a way to connect to the Master socket. ADSL2+ is quick to respond to losses of synchronization and v...ery slow to catch up once line conditions change.

And finally, thanks to Rik et al for their patience and well-considered and knowledgeable advice.

[Rik]

Thanks for the update. Nice analogy that, I'm just off to water my router.

[pctech]

careful not to over do it though as it could just sync.

[Rik]

[pctech]