data rate is not in line with the sync

I know that the guys from Xilo check here, so I'm going to try to be kind.
I've been with them on their "pro 16 Home" package for a month now and haven't received speeds of higher than 2Mb/s (actual dl speed fluctuates around 1.5Mb/s). This is fine obviously for email/basic web... but useless for video streaming. BBC iPlayer, Sky Player and YouTube are all un-usable.
I have tested at various times of the day, changed ADSL filters, tried 2 different routers etc. and still nothing. Living in London, approx 1 mile from Kentish Town Exchange (CLKEN) I had hoped/expected more.
So here is my problem. Xilo have escalated the issue with C&W who are adamant that I am syncing at 19Mb/s (my router currently shows 9470kbs) and "can see no fault". This brings us to the dreaded Engineer visit. I am only in this property for 1 more month and am loathed to spend any more money (I have already bought a new Billion 7800n Modem to try to solve the problem). I am even considering not paying my £17.99/month I am so unhappy with the service I am receiving.
The people before me in the flat had an "up to 8Mb/s" service with Orange and regularly achieved 5-6Mb/s dl. So I really doubt there is anything drastically wrong internally.

ADSL Link Downstream Upstream
Connection Speed 9470 kbps 1023 kbps
Line Attenuation 280 166
Noise Margin 86 db 66 db

The guys at Xilo haven't solved this, all they seem to be able to do is pass it back to C&W and tell me how much it will cost to send an engineer out. So I doubt they will have any problem with me asking here: "what would you do" ?

edit: I should add - I've been using : http://speedtest.uno.net.uk/ to test my speed (but others concur).
MTU was set to 1500, which offered marginal speed improvement, but was advised by Tom@xilo to change it back to 1432... which is where it is at.
There are no other lines/phones/extensions in use in the flat
Updated router firmware to 1.06c
Although slow the connection seems stable (i.e. I think I've seen up to 8 days connected, but with all the tests its hard to tell)

Edited by deleted (Wed 27-Apr-11 17:01:48)

In reply to a post by ataub:

I know that the guys from Xilo check here, so I'm going to try to be kind.
I've been with them on their "pro 16 Home" package for a month now and haven't received speeds of higher than 2Mb/s (actual dl speed fluctuates around 1.5Mb/s). This is fine obviously for email/basic web... but useless for video streaming. BBC iPlayer, Sky Player and YouTube are all un-usable.
I have tested at various times of the day, changed ADSL filters, tried 2 different routers etc. and still nothing. Living in London, approx 1 mile from Kentish Town Exchange (CLKEN) I had hoped/expected more.
So here is my problem. Xilo have escalated the issue with C&W who are adamant that I am syncing at 19Mb/s (my router currently shows 9470kbs) and "can see no fault". This brings us to the dreaded Engineer visit. I am only in this property for 1 more month and am loathed to spend any more money (I have already bought a new Billion 7800n Modem to try to solve the problem). I am even considering not paying my £17.99/month I am so unhappy with the service I am receiving.
The people before me in the flat had an "up to 8Mb/s" service with Orange and regularly achieved 5-6Mb/s dl. So I really doubt there is anything drastically wrong internally.

ADSL Link Downstream Upstream
Connection Speed 9470 kbps 1023 kbps
Line Attenuation 280 166
Noise Margin 86 db 66 db

The guys at Xilo haven't solved this, all they seem to be able to do is pass it back to C&W and tell me how much it will cost to send an engineer out. So I doubt they will have any problem with me asking here: "what would you do" ?

Well from the stats you have posted with an attenuation of 28db down/16.6db up
I would expect to be seeing around a 15-16mbit sync on a target snr of 6db (interleave) higher if on fastpath, the sync being lower than it should , could be an indication of a fault,
but also could be due to other things such as the actual quality of the line its self or the C &W llu kit at fault, if it's down to the bt line,being of poor quality or because it's being subjected to interference would mean that Any adsl2+ service would show similar issues as it would appear to affect the frequencies it uses,where as it isn't as noticeable on the adsl1 gdmt frequencies
Although it won't make much of a difference you could ask to have the downstream snr target set to 6db instead of the 8.6-9db it appears to be set at, that will increase the sync slightly ,but won't improve throughput,

Edited by tommy45 (Wed 27-Apr-11 17:13:31)

if it's down to the bt line,being of poor quality or because it's being subjected to interference would mean that Any adsl2+ service would show similar issues as it would appear to affect the frequencies it uses,where as it isn't as noticeable on the adsl1 gdmt frequencies

Well that would seem to make sense, because the previous tenants' ADSL1 connection was behaving normally, and my ADSL2+ is crippled.

There's something seriously wrong with these stats

ADSL Link Downstream Upstream
Connection Speed 9470 kbps 1023 kbps
Line Attenuation 280 166
Noise Margin 86 db 66 db

Assuming you've missed a 1 from the sync speed, meaning you sync at 19megs, and you've missed a decimal point from the attn and snr, you're probably getting 2MB download which is all correct.

Edited by deleted (Wed 27-Apr-11 20:36:24)

Force your modem to use ADSL mode, does this improve the throughput?

Also make sure your bits and Bytes are not confused

annoyingly that is how the billion 7800n modem reports the stats.
I haven't missed a 1 from the sync speed - it is showing approx 9000kbps
the attn and snr almost certainly are missing decimal points though.
I'll put up a screen grab when I get home.

And I will also try to force connecting at ADSL1 and see what happens.

Its just how the modem reports the stats, you can see here: Screencap of ADSL stats
Upstream 1023
Downstream 9571
SNR Margin(Upstream) 61
SNR Margin(Downstream) 94
Line Attenuation(Upstream) 165
Line Attenuation(Downstream) 280

useful eh?
Gonna try switching to ADSL1 now.

Well that helps! [img]http://speedtest.uno.net.uk/result/29686/[/img]
Connecting with G.DMT gives me 5.5Mbps which I can live with for a month.
wonder why Matt and Tom from Xilo didn't suggest it?

Edited by deleted (Thu 28-Apr-11 19:21:18)

Just a short reply which mirrors that of the ticket as I am currently OTR.

This was already attempted as part of standard diagnostics and made no difference to the throughput rates that you were reporting so was set back to the standard 'MM 16Mb 9db/8ms" profile.

I'll update the ticket when I'm back at a computer with the dates but one thing to point out, on the stats we were and still see on the port, it is showing 19Mb sync with all other stats matching, which has further added more confusion to the problem.

C&W have indeed been investigating, which has taken longer than we'd like simply due to the complexity of the fault and that everything that was attempted on the circuit did not appear to help from your own results.

Matt

Billion obviously work in cB ( centiBels) >>>> 100(log(P1/P2))

It's actually a bug... which is fixed in a newer firmware

Matt