BT Line Stats Random connection drops.

Rangler · 27 Jan 2012 at 15:51

Hi All im having a problem with a friends BT connection
These are his current line stats do they look particularly bad.?

ADSL Information ( SDSLADSL Firmware Version: 232201_A)
ATM Statistics
TX Cells 1950295
RX Cells 12013095
TX CRC errs 163
RX CRC errs 2302

--------------------------------------------------------------------------------

Mode State G.DMT SHOWTIME
Up Speed 160000
Down Speed 4448000
SNR Margin 10
Loop Att. 45

Thanks for any replies.

InQ · 27 Jan 2012 at 16:04

4.4mbit is inline with a line attenuation of 45dB and SNR margin of 10dB.
It could get more speed to 5-6mbit if the SNR margin was dropped to 6dB.
This is assuming whats quoted (SNR Margin 10 and Loop Att. 45) above is for the down speed.
The up speed is low though, 0.16mbit when the normal is 0.4mbit and usually achieveable for a lot of people especially considering your down speed.

What router is it?
And when you say connection drops you mean loss of sync or are they just ISP drops?
How is the wiring and filters from the master socket arranged? Is there other extensions from the master socket? Bad internal wiring arrangements can account for quite a lot of problems.

DJMK4 · 27 Jan 2012 at 16:06

Stats show that the attenuation is mid-highish, SNR margin shows its been raised from the standard SNR profile of 6db to a higher one of 10db (assuming thats downstream SNR margin), so if a line is on a standard profile and is dropping, it will be increased to 10db to help stabalise it, but it sounds like that is still dropping, I would start looking at "WHY" its dropping.

Has he changed all the cables/filters at the house? is he plugged directly in to the master socket? does he use any extension cabling or have any other devices like a fax etc or anything else sharing the filter on the master socket with the router?

Has he plugged the router in to the test socket behind the master socket to see if it still drops?

Has he plugged an analogue phone in the phone line to see if he gets a clear tone using quiet line test?

he can also try and get them to put him on the next profile up to help stabalise it, however this will mean decreased sync speed but "hopefully" improved stability, on the flip side it might not work if there really is something that's putting a stick in the spokes.

Once he has fixed the issue with the drops, he can reset his SNR back to its standard 6db, hopefully giving him better speeds, and no drops.

Rangler · 27 Jan 2012 at 16:10

The router is a draytek 28020.
Plugged straight into BT master socket, nothing else on the line no telephones nothing.

Going round with 2 other modems on Monday am to test.
ISP done a line test and said its his hardware!!, we'll see.

Anyone done the "RING WIRE" trick.? tempted to remove it from pin 3 and see if it helps.

Rangler · 27 Jan 2012 at 16:12

What is this "Quiet line test" you speak of.? Will take a analogue phone round to test.

InQ · 27 Jan 2012 at 16:14

Rangler said:
What is this "Quiet line test" you speak of.? Will take a analogue phone round to test.

Dial 17070 and follow the instructions to pick the quiet line test to listen for noise on the line.

PS is he on ADSLMax/up to 8Mbit and not on an LLU provider?

Rangler · 27 Jan 2012 at 16:17

Im Sure hes on ADSLMax but not certain, any easy way to find out ?

InQ · 27 Jan 2012 at 16:18

Rangler said:
The router is a draytek 28020.
Plugged straight into BT master socket, nothing else on the line no telephones nothing.

Going round with 2 other modems on Monday am to test.
ISP done a line test and said its his hardware!!, we'll see.

Anyone done the "RING WIRE" trick.? tempted to remove it from pin 3 and see if it helps.

If its got the ring wire connected then thats the no 1 culprit although you said nothing else was connected but the router? :confused:

You might be best taking off the NTE5 bottom half and using the test socket behind it. Does it drop quickly or does it drop say once every few days?

Also if you can it might be worth running Routerstats Lite for a few days to plot the noise margin and sync 24/7.
http://www.vwlowen.co.uk/internet/files.htm

InQ · 27 Jan 2012 at 16:24

Rangler said:
Im Sure hes on ADSLMax but not certain, any easy way to find out ?

His ISP?
In his router stats info does it mention he is connected by G.DMT?

Try and telnet in and bring up more stats that way:-
http://www.kitz.co.uk/routers/telnet_router.htm

Not sure on the commands for Draytek though...

Rangler · 27 Jan 2012 at 16:25

Cheers all i shall go armed to the hilt

Rangler · 27 Jan 2012 at 16:25

Of course ISP .. Doh sorry long day.., will ask him.

Rangler · 27 Jan 2012 at 16:28

InQ said:
His ISP?
In his router stats info does it mention he is connected by G.DMT?..

In OP .. Mode State G.DMT SHOWTIME.

InQ · 27 Jan 2012 at 16:31

Ah yes. Speed is inline with stats then but the upload is on the low side.

Rangler · 27 Jan 2012 at 16:37

Correct me if im wrong but doesnt G.DMT indicate standard ADSL and NOT ADSL2+ Reach.??

DJMK4 · 27 Jan 2012 at 17:11

Rangler said:
Correct me if im wrong but doesnt G.DMT indicate standard ADSL and NOT ADSL2+ Reach.??

Correct, if its on G.DMT it will be using G.DMT mode and not the ADSL2+ path, it will also be limited in terms of sync ala ADSL/ADSL max. However if just because it is showing "G.DMT" doesnt mean he has manually selected, he could be on auto where it will pick this up automatically based on what type of connection he is on.

Most conventional routers are set to multi-mode or auto in some way with the ability to "lock down" to G.DMT if it doesnt automatically connect to it.