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Standard User mabibby
(learned) Tue 31-Jul-12 23:43:40
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Gained 1mb Sync Randomly....


[link to this post]
 
Hello,

I'm one of those unfortunate ones who deals with single figure Mb speeds.

I've for 2 years have ben syncing at a solid 3mb... (ADSL 2/2+) but, all of a sudden today i'm now syncing and downloading at 4Mb?!?!

Stats below...

ADSL Link Downstream Upstream
Connection Speed 4094 kbps 794 kbps
Line Attenuation 58.5 dB 36.0 dB
Noise Margin 4.9 dB 7.4 dB

Potential BT copper upgrade? E-Side? Any ideas?

Regards
Matt

Sky Unlimited
4.3MB @ 4.5KM Line Length smile
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Standard User tommy45
(knowledge is power) Wed 01-Aug-12 00:50:16
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Re: Gained 1mb Sync Randomly....


[re: mabibby] [link to this post]
 
ADSL Link Downstream Upstream
Connection Speed 4094 kbps 794 kbps
Line Attenuation 58.5 dB 36.0 dB
Noise Margin 4.9 dB 7.4 dB


Looks to me like the downstream NM maybe was higher than it is in the stats at the time sync was established , as sky's default target nm is 7db not 5db , that's the reason you got a slightly higher sync, which would suggest that your line is capable of a bit more speed, but their one size fits all approach is basically capping the potential of the line,

Standard User RobertoS
(sensei) Wed 01-Aug-12 01:07:08
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Re: Gained 1mb Sync Randomly....


[re: mabibby] [link to this post]
 
I'm confused?

You say you are on Sky Unlimited, which is LLU, but this is the forum for the discussion of the technical aspects of BT Wholesale connections.

Completely the wrong place I would have thought. BT Wholesale has nothing at all to do with your service. Why not the Sky forum or General Broadband Chatter?

My broadband basic info/help site - www.robertos.me.uk
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Standard User ukhardy07
(experienced) Wed 01-Aug-12 04:58:00
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Re: Gained 1mb Sync Randomly....


[re: mabibby] [link to this post]
 
Looks like SKY DLM has re-trained the line. Looks like it's set an optimistic sync...

If you sync at around 10am you'll get better speeds than say 7pm

The speed it's set you to allows the noise margin to go below 7db if you sync at around 10am I'm guessing.

smile Your line must be very stable for DLM to set it like this. On my line it took 2000 hours of constant uptime before it did the same thing. This was with NO drop outs.

Now on fibre so it's totally different though.

Edited by ukhardy07 (Wed 01-Aug-12 04:59:18)

Administrator MrSaffron
(staff) Wed 01-Aug-12 08:57:05
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Re: Gained 1mb Sync Randomly....


[re: ukhardy07] [link to this post]
 
I have seen another line or two with Sky heading down towards the 3dB target level now, wonder if they are trying this out, in a move to ensure BT Wholesale is not faster on ADSL2+

Andrew Ferguson, andrew@thinkbroadband.com
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User mabibby
(learned) Wed 01-Aug-12 23:36:35
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Re: Gained 1mb Sync Randomly....


[re: RobertoS] [link to this post]
 
Yeah apologies, I posted this last night when my brain wasn't functioning 100%.

I guess I was trying to post in a section where i'd get the more "intellectual" types replying. I assumed maybe the Sky section wasn't aimed at the technically minded wink

Sky Unlimited
4MB @ 4.5KM Line Length smile
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Standard User XRaySpeX
(eat-sleep-adslguide) Thu 02-Aug-12 02:40:41
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Re: Gained 1mb Sync Randomly....


[re: RobertoS] [link to this post]
 
Perhaps OP thinks this forum covers BT OpenReach in the absence of such forum.

1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 19 Meg WBC
Standard User ukhardy07
(experienced) Thu 02-Aug-12 04:17:50
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Re: Gained 1mb Sync Randomly....


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
I have seen another line or two with Sky heading down towards the 3dB target level now, wonder if they are trying this out, in a move to ensure BT Wholesale is not faster on ADSL2+


Sky are definitely setting lines with speeds higher than they used too.

In the old days, say if my line synced at 6Mbps with 7db noise margin at 10am. This noise margin may go down to 4db by 8pm. DLM used to notice this and set the target sync lower, say 5.5Mbps. This resulted in a high noise margin 24/7 & often resulted in double digit noise margins at around 10am...

Nowadays. Say I sync at 6Mbps with a 7db noise margin at 10am. This noise margin may go down to 4db by 8pm. DLM now seems to keep this target sync, despite it regularly resulting in a low SNR. As long as it's stable DLM doesn't seem to care anymore.

If the user syncs at 10am, they will get an SNR of 4db by 8pm. If the user syncs at 8pm, their sync will be lower than 6Mbps and their noise margin will be 7db. By 10am the following day, the SNR is likely to be in double figures.

Sky are definitely not doing a 3db noise margin. At time of sync it's always 7db. However DLM is often setting syncs above what it used too like in the above example.

So when you see someone on Sky with a low SNR, it just shows that their noise margin is some-what varient... Skys NETGEAR routers used to show an SNR of 5db difference over a full day on my line. Whereas the sagem is always within 2db. So the router makes a big difference too.

Fibre is completely different as I'm sure you know.

Edited by ukhardy07 (Thu 02-Aug-12 04:20:01)

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