7Mbps v 2 Mbps

So on one line I get 2208Kbps download and on the other I get something around 7500Kbps download (both sync speeds).

These lines are very nearly right beside each other, they are within 10 metres of each other.

One is on BT (the 7500Kbps line) and the other is with Sky (both line rental + broadband).

I called up Sky today and told them this and they said that it must be a problem with my router. I told them that I've tried different routers and they continue to blame it on the microfilters etc.
They asked me if I plugged the modem directly into the test socket and I had did this, not a difference.

Does this mean that it is a problem externally? On the other line which is now achieving 7Mbps sync, I was previously getting speeds like this. It took six engineers and finally I complained to BT's CEO and he sent out probably one of their best engineers. He replaced the cables on the pole outside and told me that I had got the last pair or something and that if there was any other problems they'd need to get an underground team out.

So here's my router stats:

ADSL Link Downstream Upstream
Connection Speed 2208 kbps 448 kbps
Line Attenuation 37.0 db 19.5 db
Noise Margin 6.1 db 10.0 db
Poll Interval: (secs)

They are basically identical on the other line (with the best speeds except the downstream speed is different obviously).

My questions:

1) If it does prove to be a fault on the pole, what happens next? Will they just say that they can't do anything because there's no more space left for anymore lines on the pole?

2) Does it mean if I plug into the test socket that it's a problem externally? There's no noise on the line.

3) How can I ensure I won't be charged if Sky give in and send an engineer out?

By the way, both lines are connected to the same cabinet. Get around the same attenuation and I have confirmed this with BTW.

Thanks

Jack

For a more informed answer you need to post the line stats from the router on the dodgy line.

It is quite possible that the dodgy line takes a different route back to the exchange.

That is a noisy line ...

What are the comparative figures from the good line?

They may go back to the same cabinet but from there they could be in different cables back to the exchange or even different parts of the same cable and it is picking up more interference.

Without curing that and it could be near impossible there is not much you can do.

Dodgy line stats are above.

From the good line:

VPI/VCI 0/38
Type PPPoA
Modulation G.992.1 Annex A
Latency type Interleaved
Noise margin (Down/Up) 8.5 dB / 6.0 dB
Line attenuation (Down/Up) 35.1 dB / 19.5 dB
Output power (Down/Up) 5.9 dBm / 0.3 dBm
Loss of Framing (Local/Remote) 0 / 0
Loss of Signal (Local/Remote) 0 / 0
Loss of Power (Local/Remote) 0 / 0

ADSL Downstream:
7328Kbps

ADSL Upstream:
448Kbps

In reply to a post by jdowning640:

From the good line:
Output power (Down/Up) 5.9 dBm / 0.3 dBm

Funny! Power looks low on good line. What is it on bad line? Also, bad line's equivalent of this:

In reply to a post by jdowning640:

Modulation G.992.1 Annex A

Is the Sky line an LLU service - if yes then it may be their DLM has locked you down to a 2Meg profile - if line always syncs at 2208 then that almost confirms this

Looking at your stats I would have thought that noise is the problem?

Noise margin on good line: 8.5 dB
Bad line: Noise Margin 6.1 db

I have a noise of about 6, and my speed synched at 5Mbps by the end of the test.

I did some investigation, and swapping out the old microfilter and putting the new one in, made a huge difference (jumped to over 10dB). I convinced Sky to retry now that I had sorted out the noise, and I jumped to synching at 14.5Mbps, that has dropped to 12Mbps today but even so, much more what I would expect based on the attenuation for the line.

Hi Nicky & MrSaffron,

LLU isn't enabled on my exchange so it's definitely not.

It sync always between the region of 2xxx. It can fluctuate at times so I don't think it's a profile which has been locked.

I've tried different micro filters and tried using the test socket but no difference.

What next?

Thanks, Jack

Hi guys,

Have booked an engineer with Sky (BT Openreach) but I need to ensure that I won't be charged a fee.

Is it definitely within their range of problems if I've tried the test socket?

I have until tomorrow to confirm! Please help.

Jack

Is this a LLU service? If yes, has sky confirmed they are not limiting the line to 2Meg?

Hi mrsaffron

There is no LLU providers at my exchange. It's not activated.

Thanks
Jack

In reply to a post by MrSaffron:

Is this a LLU service?

Connection Speed 2208 kbps 448 kbps

Do you know if it is a problem on my side xrayspex? And MrSaffron probably just glanced over the stats, don't worry about it

While the 448Kbps is usually a sign of IPStream Max, if an ISP has forced a 2Meg profile, they might force the upstream to a slower speed too.

If this IPStream Max and the modem is not doing a massive power backoff, then the suggestion is something wrong with the line, or a line card port that is giving grief

I complained to BT's CEO and he sent out probably one of their best engineers.

Probably one of the funniest thing's Ive ever seen because as far as I'm aware, last time I saw him on Directory he didn't have Openreach as his LoB

In reply to a post by krazykizza:

Probably one of the funniest thing's Ive ever seen because as far as I'm aware, last time I saw him on Directory he didn't have Openreach as his LoB

He's Chief Executive of BT Group?

Edited by deleted (Sun 20-Mar-11 00:57:33)

Hi guys,

On my good line with the extremely high ping (as always), I've just got these stats -

Can someone tell me if this noise margin is acceptable?

DSL Status: Up
DSL Modulation Mode: GDMT
DSL Path Mode: FAST
Downstream Rate: 7872 Kbps
Upstream Rate: 448 Kbps
Downstream Margin: 3 db
Upstream Margin: 23 db
Downstream Line Attenuation: 35
Upstream Line Attenuation: 20
Downstream Transmit Power: 0
Upstream Transmit Power: 0

Thanks

Jack

Nothing wrong with that ...

Can I guess that you have a 2wire2700HGV modem/router on that line?

In reply to a post by jdowning640:

Can someone tell me if this noise margin is acceptable?
Downstream Margin: 3 db

Depends! It's bit low unless you are intentionally tweaking it or you took reading after dark. Better to get router stats after reconnecting during daylight.

Your power readings are still suspicious.

Edited by XRaySpeX (Mon 21-Mar-11 22:44:30)

In reply to a post by XRaySpeX:

In reply to a post by jdowning640:

Can someone tell me if this noise margin is acceptable?
Downstream Margin: 3 db

Depends! It's bit low unless you are intentionally tweaking it or you took reading after dark. Better to get router stats after reconnecting during daylight.

It's not low - it is NORMAL on a good BT Business line with an 2wire 2700 modem

I stand corrected! Did he say he was on a BT Business line? His NM was 8.5 dB 4 days ago.

at that time he had 8.5 dB and 7.3Mb which suggest as a couple of reyncs just before that possibly because of a burst of noise and the SNR then rising whereas now it is 3dB and 7.8Mb.

I'm on a BT Business Broadband package (residential line) but not using the router/modem you mentioned - am using a Linksys WAG354G.

Could I get my sync any higher? No?

BT Business will work wit a 3dB SNR - I have not seen it with any other ISPs though. and it only seems to happen on good quality lines. Yours is he first time I have heard of it with a non 2700 router though.

And no, you will not get better speeds on that line.

In reply to a post by MHC:

BT Business will work wit a 3dB SNR - I have not seen it with any other ISPs though. and it only seems to happen on good quality lines.

I think several ISPs have the option available, but as you indicate it needs an exceptionally stable, quiet line.

In reply to a post by MHC:

at that time he had 8.5 dB and 7.3Mb which suggest as a couple of reyncs just before that possibly because of a burst of noise and the SNR then rising whereas now it is 3dB and 7.8Mb.

For what it's worth, I don't believe that computes!

A drop of (8.5-3) dB NM should give well in excess of increase of (7.8-7.3) Meg Sync.; more like +1 to 2 Meg.

If the exchange were to be ADSL2+ enabled, what speeds would I expect? And would I expect the same if FTTC was available? (is available although can't get it... the cabinet is situated above 20 metres from exchange, exchange = 2 miles away.).

About 10 Meg Sync on ADSL2+.