Sky Hub synced with SNR of 3.0

[nevets5891]

As the title says my wee sister's Sky broadband on the SVBN with a Sky Hub, has synced with the exchange to 21 meg with a noise margin of only 3.0. I thought Sky always synced to 7 ish?

Mine is synced with the same exchange with the Sagem F@ST2304 to 16 meg with a noise margin of 7.0. We're in the same town, a similar distance from the exchange.

Any ideas why this would be? Is it that the newer Hub allows a lower SNR?

[dholdi]

Any ideas why this would be? Is it that the newer Hub allows a lower SNR?

I think its more likely to be the dlm process deciding that the level of errors at 3db is acceptable.

It tried mine at 18.5 meg @ 3 db however went back to 6 db so I would assume the errors at 3db were deemed too high.

I might be wrong and that's got nothing to do with it but it makes sense to me

Personally, I would rather have a stable 16.5 meg at 6 db than an unstable 18.5.

[Scubbie]

Sky changed the DLM software around March/April last year to allow the Noise Margin to go as low as 3dB. Since then we have seen many connections go above 20mb and the Noise Margin frequently below 7dB.

The updated the DLM software again earlier this year and in some cases where the customer has either the Sagem 2504N (with the most recent firmware) or the Sky Hub SR101 the new tweak can kick in and improve the connection speed even more than previously.

The quality of the line needs to be good. If it isn't, then the DLM software will increase the Noise Margin to compensate.

We have often seen new connections drop to 3dB during the initial training, then rise to around 6dB. In theory though any figure below 7dB to 3dB can be used now.

The latest tweak only works on some of Sky's kit at the moment and when you are fully connected. I was on WLR3 so would not have benefited.

[gymno]

I think i may have benefited from this 2nd update to DLM Scubbie, but my 2504N still has the old firmware:

ADSL Firmware Version A2pD030n.d23b
Firmware Version 5.23.1a4N

[nevets5891]

Sky changed the DLM software around March/April last year to allow the Noise Margin to go as low as 3dB. Since then we have seen many connections go above 20mb and the Noise Margin frequently below 7dB.

The updated the DLM software again earlier this year and in some cases where the customer has either the Sagem 2504N (with the most recent firmware) or the Sky Hub SR101 the new tweak can kick in and improve the connection speed even more than previously.

The quality of the line needs to be good. If it isn't, then the DLM software will increase the Noise Margin to compensate.

We have often seen new connections drop to 3dB during the initial training, then rise to around 6dB. In theory though any figure below 7dB to 3dB can be used now.

The latest tweak only works on some of Sky's kit at the moment and when you are fully connected. I was on WLR3 so would not have benefited.

Thanks for that information. I might have so get an SR101 and see if I can benefit from this.

[Scubbie]

I was re-reading the information late last night. Just to clarify at the moment the Sagem 2504N and Sky Hub SR101 are both part of the components for this. It is intended to enable the same feature on the other Sky routers in due course, just not yet.

[Shonk]

Got a link?

[Scubbie]

I can't provide a direct link but I can provide some other information on the topic.

Essentially the Sky Hub SR101 and the Sagem 2504N both support "G.INP". This has now been rolled out to Sky's ISAM hardware. The intent is to do the same for the other Sky routers in due course.

At the present time G.INP will not be available off Sky's kit.

Looking around the Internet there are various articles on G.INP. I don't know which technical aspects Sky have incorporated but the articles are interesting to read. Below are just a few of these articles. Please feel free to google more:

DSL Xpert Support G.INP

Saving Copper

MT2311 & MT3302 **Soon Available**-VDSL2 & ADSL2+- |

DSL Expresse Software - ASSIA

ITU-T Recommendation database

One of the most interesting aspects which will please those who can benefit from this is the reduction of the effect which REIN can cause.

[mattan]

Just read the "Saving Copper" article and think we should ask for some of that NodeScale vectoring!

[nevets5891]

I'm bidding on a few SR101-Z's on ebay. Do you think I'd have to get DLM re-enabled on my line to get this benefit? I recently got reprofiled to 15Mb\1Mb on the gamer profile, then it automatically jumped to 16Mb\1.2Mb about a week later.