Line fault

We have had a good broadband connection for a long time. Last wednedsay BT upgraded our connection to ADSL2+.
After the upgrade i have noticed the BB conection re-syncing itermitently. Over the last few days i have tried to identify whats been causing the re-syncs. I have noted that the re-syncs only occur on incomming telephone calls being answered. I get no problems on outgoing phone calls. I have replaced my filtered face plate with a spare i had known to be in working order(new), replaced my router with the spare one and changed the telephone.
Today i contacted BT my isp for help. I told them about my broadband problems and what i had done to investigate this on my side. They did a line test and called me back to tell me that there was a problem with ADSL2+ upgrade done last week on my line. They also stated that the test showed that the line to my property and connected items within my house were tested showing a good satisfactory result I was told that they needed to syncronise the autentication on my line back at the exchange and this would be done in the next 24/48hrs.

I would be grateful if someone could educate me on what this repair at the exchange could be.
Apart from the re-syncs on incomming calls the connection is fine.
Overall quite pleased with BT just hope now that this repair at the exchange solves my line problem.

Can you post your line stats (connection speed, line attenuation, noise margin, etc.)?
Are you connecting at about the same speed as before, or is it much faster?

If much faster (practically all lines which used to connect at 8Mbps will go much faster with ADSL2+ and, thus, require "more" out of the phone cable).
For some lines (e.g. ones fed from telephone poles, or houses with large or dodgy extension wiring) this can be a problem and lead to a bit of instability.

In reply to a post by adebov:

Can you post your line stats (connection speed, line attenuation, noise margin, etc.)?
Are you connecting at about the same speed as before, or is it much faster?

If much faster (practically all lines which used to connect at 8Mbps will go much faster with ADSL2+ and, thus, require "more" out of the phone cable).
For some lines (e.g. ones fed from telephone poles, or houses with large or dodgy extension wiring) this can be a problem and lead to a bit of instability.

Below is the line stats taken from the BT Voyager 2500V router.

Line Mode ADSL2 Line State Show Time
Line Power State L0 Line Up Time 00:03:17:22
Line Coding Trellis On Line Up Count 14

Statistics Downstream Upstream
Line Rate 4629 Kbps 780 Kbps
Noise Margin 6.1 dB 5.1 dB
Line Attenuation 51.5 dB 28.8 dB
Output Power 19.3 dBm 12.3 dBm
MSGC (number in overhead channel data) 60 24
B (number of bytes in Mux Frame) 142 32
M (number of Mux Frames in FEC Frame) 1 2
T (Mux Frames over sync bytes) 1 2
R (number of check bytes in FEC Frame) 10 16
S (ratio of FEC over PMD Frame length) 0.9816 2.6667
L (number of bits in PMD Frame) 1247 246
D (interleaver depth) 32 8
Delay 7 msec 5 msec
Super Frames 731208 731206
Super Frame Errors 1305 13707
RS Words 48259762 24861004
RS Correctable Errors 253574 6657433
RS Uncorrectable Errors 9607 0
HEC Errors 1175 0
OCD Errors 0 0
LCD Errors 0 0
ES Errors 0 0

Since the upgrade from last week the re-syncs only occur on incomming calls. I have configured the router now to connect on ADSL2
The down stream sync is relatively about the same as prior to the upgrade. The line errors on the down stream is also about the same as before.
The upstream however has increased from 448kbps to 780 to 850kbs. Also the upstraem RS Correctable Errors are very high. Previously this use to be below 100 over a period of over 30 days.

BT just called me ten minutes ago to say that the line needs to be checked by a line engineer tomorrow. Yesterday they stated that the test showed that the problem was at the exchange.
Im just hoping now that they don't charge me and say nothing is wrong.

4629kbps isn't too far off what should be possible with a 51.5dB line.
Mine's 56dB on ADSL2 (a little higher on ADSL2+) and I can get around 4300kbps with a 6dB margin (and around 4800kbps with a 3dB margin).

It may be your line is one of those which will need a 9dB target margin.
You may want to try the router plugged directly into the 'test' socket INSIDE the BT master phone socket (i.e. under the removable lower front cover), to see if it's either faster or more stable (because your phone extension wiring may be dragging in a bit of interference and causing the re-syncs).

But....Remember this is still a BT product so don't muck about too much (forced re-syncs, forcing modulation types) as the BT DLM may well bite you in the ass and stick you on a 15dB margin (losing masses of speed).

Thanks ADE for your posts.

I have already tried the test socket with just a router and telephone plugged in. I have tried two different routers at the test socket and two different telephones. The sync still drops on incomming calls.
The spare router is a new BT Voyager 2500V which i have kept from a long time.
I am just a little worried that yesterday BT said that the line test carried out which included my installation all connected including secondary sockets, routers etc showed that there was a problem at the exchange and that my installtion tested good. I dont really want their call out charges and some engineer claiming that the line is fine tommorrow. I wonder whats changed from yesterdays line test of the exchange problem.
Its seems a little strange that the problems only started last wednesday the day of the free upgrade which i didnt ask for in the first place.

Just hoping that the line engineer tommorrow will find something external from my property.
My guess is that the upstream sync is whats causing me the problems. 9db on the upstream to get a stable connection is no problem to me as this would probably put the upstream sync to what it use to be on the max product.

I visit these forums quite regularly. In the past i have read a lot of posts where a lot of people have shown their dissatifaction towards BT rightly or wrongly.
I must either be lucky or BT are improving with their customer services.
I have just recieved a phone call from BT to state that they will need to visit my property this afternoon regarding my recent BB issues. I have so far found them very helpful and very eager to discuss in alot detail the exact nature of this fault. They have re-assured me that i would not get charged for this visit as the actual fault is on the D Side? between the line to my house. He also confirmed that their detailed test confirmed that my filters and equipment in the house showed no problems.

Just got to make sure that hot food and drinks are catered for the engineer in these servere cold weather conditions.

Arrr YES I remember this happening to me when my line was upped to ADSL2+

Drove me nuts for a few days.

Do you have other hard wired phones in the house that have a ADSL Filter on the socket?

I had two hard wired phones in the house and I changed both the filters and hay presto all back to normal. So I guess one of the filters was dodgy or old and could not cope with the ADSL2+.

Hope that helps

Simon

In reply to a post by Simon888:

Arrr YES I remember this happening to me when my line was upped to ADSL2+

Drove me nuts for a few days.

Do you have other hard wired phones in the house that have a ADSL Filter on the socket?

I had two hard wired phones in the house and I changed both the filters and hay presto all back to normal. So I guess one of the filters was dodgy or old and could not cope with the ADSL2+.

Hope that helps

Simon

Many thanks simon for your advice which is very much appreciated.
From my earlier posts here is the update so far.
The original OR engineer failed to turn up on Tuesday. Instead i had a phone call from someone who said they were at the exchange and that they had done some repairs and the line tested ok now. I tested the line myself by ringining my home telephone only to find that on incomming calls i still lost the sync.
I called BT BB again. Again BT CS india were very good. They re-did a line check and confirmed that they results show a fault at the exchange and a fault to the D Side. The re-assured me that the test also confirmed that my house wiring and equipment showed a OK. They also were very dissapointed that the engineer did not come to my house to test the line from the house test socket and back to the exchange.
A new appointment was made for the following day(Wednesday).
At about 10 oclock i had a call from an OR engineer who asked if he could cancell this appointment as it was snowing quite bad and he would be travelling from outside my home town.
I could quite easily see from looking from my window that he was corect that the snow was very bad so i stated to him that a few days before christmas the health and safety of him was more important to me than my BB.
BT BB CS India called me again and thanked me for my understanding for the well being of the OR engineer,

Today i have just tried a nother brand new filter and a previously unused home hub at the test socket at my home. The homehub keeps dropping the sync every few minutes and will only connect if a telephone is connected to the filter as well.

So it defantly looks as if there is a line fault back to the exchange and its getting worse.

I have a new appointment now for an OR engineer on 29 December.
I think as the line is now starting to deteriate more the engineers visit should find something.

Finger crossed and hopefully the re-syncs wont spoil my christmas internet experince to much

Update:-

Yesterday i had a BT Engineer visit my house to resolve my recent ire-sync ssues.
He started at 10.30am and finally resolved the issue at about 4.30pm that afternoon.
He had a test instrument which he used at the bt test socket with my home wiring disconnected. He could see large errors on the upstrram. He replaced some bits at the exchange, carried out a lift and shift and something else on the eside. But i kept on getting the re-syncs. Finally they had to cap my upload to 444kbps for the line to finally stabilise. My line was re-set and my downstream sync is at 4329kbps on my 56db line. The only thing that was not changed was the cable from my house to the cab. This tested OK and showed no hr faults. The outcome i am being told is that the ADSL2+ line is a problem on my 56db att line.
I have had no re-syncs since the works carried from yesterday.
Looks like the issue might have been resolved on the price of a cap on the upload sync.

I have confirmation that i am fed of cab 82 which is programmed for fttc between jan to march 2011.
Just hoping now that the cable from the house to the cab is ok as this was about the only thing that was not replaced yesterday.

Very impressed with the BT engineer yesterday for his determination in resolving the issue and communication with me which at times was very detailed and technical.

Dont just tell us, tell his manager,