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Standard User linnite
(newbie) Mon 03-Feb-14 00:04:53
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Weird chain of events


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Hi all,

Been with TalkTalk for about a year I think, Sky and o2 before that. I have had an 'interesting time' with my BB for the last few years as I should have been able to get about 11 meg, i.e as per Openreach estimate at the time, and in fact used to get that for a while, but suddenly it dropped (possibly to coincide with getting a second line fitted for working at home) and then tended to get about 4 meg.

My attenuation is 25.6 and ouput power is 20.4, I am about a kilometre from the exchange.

Whilst with TT it has varied from about 3 meg to about 8, frequently dipping down to about 2.0 or 1.5 noise margin and either re-synching itself, or the router falling over and being restarted by me. The line seemed to be constantly in testing, hunting around for a sync it could stay at.

After a particularly bad spell a few weeks ago I reported it as a fault, got a text back from TT saying it had been resolved, for a few days it seemed like it hadn't.....but then suddenly got a nice rock solid connection albeit at 6 meg.

That's kind of the weird thing now, my noise margin is varying from about 12.0 to about 20 plus, but the line never tries to sync higher than 6 meg (6028 exactly I think). I feel sure this is somehow tied to the fact that they have, just this last week or two, done a FTTC cabinet about 150m up the road.

Has this work fixed whatever problem I was having? Does it explain the few days of appaling trouble that caused me to log the fault (was I getting unplugged and plugged in again at the exchange/cabinet?)

If so, why now stuck at 6 meg when the noise margins I am getting would probably allow for the 11 meg I used to get (funnily enough Openreach now says 6 meg is all I should expect). They don't shunt people down to ADSL2 from ADSL2+ when they install fibre cabinets do they?

Post code checking shows my exchange LCBUS is now accepting orders for fibre but the various phone number or address checkers show it as not available. I know that could change any day with this cabinet having just been done.

Hmmm. sorry for the rambling. Can anyone piece these bits of info into something that explains what's going on at all? I'm pleased to have this solid 6 meg but really want to be able to understand what has gone on.

Many thanks if you can.

-linnite
Standard User XRaySpeX
(eat-sleep-adslguide) Mon 03-Feb-14 13:55:14
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Re: Weird chain of events


[re: linnite] [link to this post]
 
In reply to a post by linnite:
My attenuation is 25.6
You should be getting about 18 Meg sync. I get that on same attn. when my NM = 6dB.
my noise margin is varying from about 12.0 to about 20 plus
That's damping your speeds; it is usually 6dB or less on a good line. Each 3dB of NM is worth anywhere between 400 to 1200kbps of speed.

Post your full router stats in 1 snapshot.

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 20 Meg WBC
Standard User linnite
(newbie) Mon 03-Feb-14 21:36:52
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Re: Weird chain of events


[re: XRaySpeX] [link to this post]
 
Hi and thanks.

Here are the stats, although obviously they can't help me understand what has been going on in the past.

ADSL
Type Interleave Path
Status Show Time
Downstream Upstream
Data Rate (kbps) 5752 921
Noise Margin (dB) 14.0 15.6
Attenuation (dB) 25.7 13.1
Output power(dbm) 20.4 12.4

Many thanks again

-linnite

Edited by linnite (Mon 03-Feb-14 21:37:34)


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Standard User XRaySpeX
(eat-sleep-adslguide) Mon 03-Feb-14 23:59:29
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Re: Weird chain of events


[re: linnite] [link to this post]
 
AS I say you should be getting about 18 Meg.
In reply to a post by linnite:
Downstream Upstream
Noise Margin (dB) 14.0 15.6
This high NM explains some of your about 13 Meg loss, but not all of it; perhaps it might account for 3 to 6 Meg loss at most.

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 20 Meg WBC
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