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Standard User schander
(learned) Fri 08-Feb-13 16:05:45
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Possible two routes for line


[link to this post]
 
Hi all,
Recently the bt adsl checker has started listing that I can get 17mbps over WBC ADSL2+. I have always been told the my line length is 5000m therefore wouldn't be able to get more than 3mpbs, which is what I have been getting for the last few years. My isp confirmed that I'm on WBC adsl2+ and have a line length of 60db, which would make my 3mpbs sensible.
My ISP is suggesting that there could be 2 routes for me getting to the exchange and that I'm connected to the longer route? given that I'm not getting the 17mbps that BT are listing on the checker.

Also I know that I was being served by a TPON cabinet (20yards form my house), however recently a OpenReach engineer said that the cabinet was no longer in use and that all the connection were done in the, recently extended manhole, next to the cabinet.

Is there any chance that BT would re-route me to the shorter line?

The ISP as arranging a engineer visit.

Thanks
Satpal
Standard User yarwell
(sensei) Fri 08-Feb-13 16:29:26
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Re: Possible two routes for line


[re: schander] [link to this post]
 
is that higher result for your number, or postcode / address ??

http://windows.mouselike.org/be/?DoAction=BrasChecker returns a line length estimate as well as a BT BRAS chack

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User RobertoS
(sensei) Fri 08-Feb-13 16:37:31
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
That's neat - the other info it gives.

Interesting it should say:-
BT Recorded Line Length to Exchange (m): 3081
BE LLU: Activated


for a Plusnet FTTC line though.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 54.3/15.4Mbps @ 600m. - BQM

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Allergy information: This post was manufactured in an environment where nuts are present. It may include traces of understatement, litotes and humour.


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Standard User yarwell
(sensei) Fri 08-Feb-13 17:16:43
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Re: Possible two routes for line


[re: RobertoS] [link to this post]
 
that's still true for FTTC isn't it ?

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User RobertoS
(sensei) Fri 08-Feb-13 17:30:40
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
The distance looks right, yes. But the line below it is rather suspect tongue smile.

Ahhh - maybe it means Available/Activated at the exchange. That's not what it says.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 54.3/15.4Mbps @ 600m. - BQM

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Allergy information: This post was manufactured in an environment where nuts are present. It may include traces of understatement, litotes and humour.

Edited by RobertoS (Fri 08-Feb-13 17:46:23)

Standard User Apprentice
(knowledge is power) Fri 08-Feb-13 17:39:42
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
Just tried it > http://oi48.tinypic.com/a1k27c.jpg

The distance to the exchange is a bit out as it's around 5 Kilometres according to the OR engineer using a hawk.

Alastair

omadasafisho
Standard User yarwell
(sensei) Fri 08-Feb-13 17:42:54
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Re: Possible two routes for line


[re: RobertoS] [link to this post]
 
see what you mean.

The distance is spot on for me, but the LLU line length database has always had its issues.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User XRaySpeX
(eat-sleep-adslguide) Fri 08-Feb-13 18:33:28
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Re: Possible two routes for line


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
BE LLU: Activated
It says that even for a line with no BB. So it must just refer to the status of the exchange.

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 schander
(learned) Fri 08-Feb-13 21:53:35
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
The higher result is for my telephone number. My postcode comes back with the speed that I'm currently getting.
The result from the link is:
This is a 21CN line
Current Down: 2.3Mbps
Current Up: 0.45Mbps
BT recorded line length to exchange (m): 4430
BE LLU: Activated
Real Error: Migration code required for this number

Thanks
satpal
Standard User yarwell
(sensei) Fri 08-Feb-13 22:18:56
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Re: Possible two routes for line


[re: schander] [link to this post]
 
A comparison point :-

BT Recorded Line Length to Exchange (m): 4123
This is a 21CN line.
The current Downstream BRAS rate is: 3.78 Mbps (6 dB SNR, 54 dB attn)
The current Upstream BRAS rate is: 0.45 Mbps

Previously the BT number checker picked up data for your active service and fed it back as available speed, this doesn't seem to be the case currently as I have a line saying "up to 3M" that syncs at 8128. Sounds like you have a database glitch the other way.

Ed to add: I guess what I'm saying is that there isn't a shorter route, the ISP might be making it up and the TPON overlay will be long back to the exchange and that won't be changed by the reconnection work unless you're on an exchange boundary and they're connecting to the "other" exchange (Hampton in Peterborough for example is fed from two exchanges) but this seems unlikely TBH.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics

Edited by yarwell (Fri 08-Feb-13 22:22:20)

Standard User schander
(learned) Fri 08-Feb-13 22:43:26
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
A comparison point :-

BT Recorded Line Length to Exchange (m): 4123
This is a 21CN line.
The current Downstream BRAS rate is: 3.78 Mbps (6 dB SNR, 54 dB attn)
The current Upstream BRAS rate is: 0.45 Mbps

Previously the BT number checker picked up data for your active service and fed it back as available speed, this doesn't seem to be the case currently as I have a line saying "up to 3M" that syncs at 8128. Sounds like you have a database glitch the other way.

Sounds reasonable. If this is the case then BT OpenReach are likely to charge for coming out frown
Ed to add: I guess what I'm saying is that there isn't a shorter route, the ISP might be making it up and the TPON overlay will be long back to the exchange and that won't be changed by the reconnection work unless you're on an exchange boundary and they're connecting to the "other" exchange (Hampton in Peterborough for example is fed from two exchanges) but this seems unlikely TBH.

BT are saying that i'm connected to cabinet 49T, I'm assuming that the T means TPON, as I said before the cabinet is not in use, well if I believe the OpenReach engineer.
Don't think that my ISP (Merula) is making it up, they're just reasoning why the adsl checker would be quoting the higher figure.
I'm pretty sure, I'm not on a exchange boundary.

Thanks
Satpal
Standard User Zarjaz
(knowledge is power) Sat 09-Feb-13 00:07:03
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Re: Possible two routes for line


[re: schander] [link to this post]
 
Surely if you were off a TPON cabinet, you'd not have an ADSL service already.

Standard User schander
(learned) Sat 09-Feb-13 07:42:18
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Re: Possible two routes for line


[re: Zarjaz] [link to this post]
 
In reply to a post by Zarjaz:
Surely if you were off a TPON cabinet, you'd not have an ADSL service already.

Then what the engineer said must be true as I have adsl.

Satpal
Standard User yarwell
(sensei) Sat 09-Feb-13 10:49:09
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Re: Possible two routes for line


[re: schander] [link to this post]
 
Don't think that my ISP (Merula) is making it up, they're just reasoning why the adsl checker would be quoting the higher figure.
that's what I mean by "making it up" - retrospectively generating an explanation to fix the observations wink

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User Chrysalis
(eat-sleep-adslguide) Thu 14-Feb-13 23:19:22
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
is that tester accurate?

The Service ID is: BBEUxxxxxxxx
This is a 21CN line.
The current Downstream BRAS rate is: 78.73 Mbps
The current Upstream BRAS rate is: 20 Mbps

So it says I have higher than the max 77.43.

The reason I did run it is from my tbb graph it looks like my modem resynced 2 days ago, but the ppp didnt timeout, I still have the same throughput meaning if it did resync its either at the same speed or higher, and my ECI telnet is now closed (dodgy ECI modem bug) so cant check the modem.

However since my ip profie wont have updated and also confirmed with my throughput (cant check on BTw tester now for 1-2 hours) the question is how is mouselike.org reporting this high profile, does it somehow read a value stored elsewhere that will come into play if I reestablish ppp?

seems according to this I am right there is 2 profiles.

http://www.kitz.co.uk/adsl/IPprofile.htm BRAS and IP profiles are seperate.

BT Infinity 2 Since Dec 2012 - Estimate 65.9/20 - Attainable peak 110/36 - Current Sync 71/20

Edited by Chrysalis (Fri 15-Feb-13 10:18:57)

Standard User BatBoy
(legend) Fri 15-Feb-13 08:20:24
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Re: Possible two routes for line


[re: Chrysalis] [link to this post]
 
It just runs the BT speedtest and reports the IP profile from that. It looks like the BRAS profile is once again not updating as I reported before Christmas. http://forums.thinkbroadband.com/bt/f/4191475-bras-p...


__________________________________________________________________________The back pedalling starts here__________________
Standard User Chrysalis
(eat-sleep-adslguide) Fri 15-Feb-13 09:50:43
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Re: Possible two routes for line


[re: BatBoy] [link to this post]
 
that BRAS profile was from the windows.mouselike.org link which doesnt run a speedtest, it just shows some stats like estimated line length and BRAS profile. (incidently 2.4km line with gives 50db attenuation on adsl).

The IP profile last time I checked I had was 69.xx mbit as my sync was just under 72mbit. Now my unlocked ECI modem however the telnet daemon has crashed on it so I cant access my sync stats until I reboot the modem (dont want to do). I had a red line on my tbb graph 2 days ago at 1am which may have been a DLM change of some sort.

Now even this morning I cannot run the BTw tester as it says this for further diagnostics..

"The Performance Tester is currently unable to run a speed test for your broadband connection. Please try again shortly, however if this problem persists, raise the issue with your service provider"

My pppoe has not been recconected at all during this time so my ip profile should (and appears to be the same), I believe I have seen it mentioned elsewhere there is 2 profiles with only one getting updated on the new ppp session which is the one reported by BTw.

Either that or http://windows.mouselike.org/be/index.asp?DoAction=B... is inaccurate and wrong.

I defenitly am not on a 78mbit ip profile at the moment, throughput matches the 69mbit profile.

I see according to kitz site the BRAS profile is indeed seperate to the IP profile, the BRAS profile it seems is supposed to be a bit higher than the IP profile.

BT Infinity 2 Since Dec 2012 - Estimate 65.9/20 - Attainable peak 110/36 - Current Sync 71/20

Edited by Chrysalis (Fri 15-Feb-13 10:24:28)

Standard User yarwell
(sensei) Fri 15-Feb-13 10:29:16
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Re: Possible two routes for line


[re: Chrysalis] [link to this post]
 
It's a lookup thing that interrogates the BT database, so it should I believe yield the same results as the BT speedtester without having to go through the speedtest.

If BT have "evolved" the systems and the tool isn't up to speed then it may be stuck with an old value. I was just using it for the line length TBH.

incidently 2.4km line with gives 50db attenuation on adsl


that's a bit [censored], mine's under 40 dB at 2.5km and I can cycle the line route with a GPS to confirm distance.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User BatBoy
(legend) Fri 15-Feb-13 10:34:03
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
In reply to a post by yarwell:
It's a lookup thing that interrogates the BT database, so it should I believe yield the same results as the BT speedtester without having to go through the speedtest.
As I said, it runs the speedtest. It's just been upgraded for the new Flash-based one.
"Tom's BRAS Checker" is back up and functional after BT redirected the old Java based site to the new Flash based test.



__________________________________________________________________________The back pedalling starts here__________________

Edited by BatBoy (Fri 15-Feb-13 10:37:02)

Standard User yarwell
(sensei) Fri 15-Feb-13 10:36:02
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Re: Possible two routes for line


[re: BatBoy] [link to this post]
 
As I said, it runs the speedtest.
Didn't see that - it runs it and hides the output ? seems a bit pointless if it gets the data anyway

eta - of course it'll be run from the server so a duff value. Doh ! more caffeine required.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics

Edited by yarwell (Fri 15-Feb-13 10:37:17)

Standard User BatBoy
(legend) Fri 15-Feb-13 10:38:48
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
Apparently, it runs a really slow test so that the results don't distort any stats that BT might analyse.


__________________________________________________________________________The back pedalling starts here__________________
Standard User yarwell
(sensei) Fri 15-Feb-13 10:39:44
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Re: Possible two routes for line


[re: BatBoy] [link to this post]
 
In reply to a post by BatBoy:
Apparently, it runs a really slow test so that the results don't distort any stats that BT might analyse.
Doesn't that just put a really slow record in the database ?

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User BatBoy
(legend) Fri 15-Feb-13 10:44:11
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
I'm not sure BT's technical programming team in India has discovered databases yet.


__________________________________________________________________________The back pedalling starts here__________________
Standard User yarwell
(sensei) Fri 15-Feb-13 11:04:40
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Re: Possible two routes for line


[re: BatBoy] [link to this post]
 
LOL. The speed test results get put in a spreadsheet or something wink

The average reflectivity of personnel entering Martlesham Heath suggests the team is Indian but may not be in India smile

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User BatBoy
(legend) Fri 15-Feb-13 11:23:46
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
When you call BT India, they can see the last few speed test results and may request a new one which they can also see. I imagine the personnel here are the ones that tell the management that everything is progressing well and to plan, but the real work is being hacked together UTC+5:30 ahead.


__________________________________________________________________________The back pedalling starts here__________________
Standard User Chrysalis
(eat-sleep-adslguide) Fri 15-Feb-13 12:00:42
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
ok.

I still cant use the BTw checker.

My line I believe resynced again last night, downwards again, and now with the HG modem back in I see different line charactersitics.

the mouselike BRAS checker now reports a much lower BRAS rate so its gone down again (so I wasnt able to check sync or ip profile by relogging in to ppp whilst I had the higher bras rate).

The sync on the HG initially had the same stats as the previous weeks so about 72/73 attainable and a sync of 71. But upstream attainable has now shot up to 32mbit. Given I seemed to briefly get a higher sync the last 2 days and my upstream has gone up again I thought ok thats good.

But now I see my downstream snrm is all over the place (and the attainable with it) so am now graphing the connection. Currently I have a 5.4 downstream snrm. Was 6.6 30 minutes ago. It seems to be slowly moving downwards. Probably another topic but the mouselike site at least does seem to be updating.

and yes the reported line length for my line seems very short compared to what my adsl attenuation was. The BTw checker estimates 4.5mbit or that length.

BT Infinity 2 Since Dec 2012 - Estimate 65.9/20 - Attainable peak 110/36 - Current Sync 71/20
Standard User yarwell
(sensei) Fri 15-Feb-13 12:29:13
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Re: Possible two routes for line


[re: Chrysalis] [link to this post]
 
there's a warning on mouselike that running it will mean you can't use the BTW test until the minimum time has elapsed, as it apparently pretends to be you running the tester.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User Chrysalis
(eat-sleep-adslguide) Fri 15-Feb-13 14:06:10
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
and that time seems to be much more than a few hours.

I couldnt run the BTw tester this morning about 10 hours after I ran it last night.

Remember in another post I mentioned to you about the power?

Well initially my line had 6.6 TX power with the 36mbit attainable upstream
Then it dropped to 5.8 with 24 attainable
Now its 6.1 with 29 attainable (Was 32 initially).

Also looking at my bitloading I can see the power output has been dropped on my D0 range, same QLN as before but now less power transmitted, so it seems DLM is fiddling with the power masking I assume to manage crosstalk.

So I think the power was increased 3 nights ago, I had temporarily a higher sync for 2 days, last night for about an hour I see sustained packetloss on my tbb graph, this may have triggered excessive errors and DLM maybe reduced the power again this morning. delay depth, inp etc. not touched still fast path.

I only used mouselike again because the BTw tester wouldnt work. I will try the BTw tester again tonight. The speedtest works but the page that shows the profile fails. It seems if I am right the BRAS updates without a ppp reconnect (after new sync), and the ip profile which is a set a bit lower than the BRAS is what updates (and what the BTw page shows) on a new ppp connection.

BT Infinity 2 Since Dec 2012 - Estimate 65.9/20 - Attainable peak 110/36 - Current Sync 71/20
Standard User yarwell
(sensei) Fri 15-Feb-13 14:20:05
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Re: Possible two routes for line


[re: Chrysalis] [link to this post]
 
Well initially my line had 6.6 TX power with the 36mbit attainable upstream
Then it dropped to 5.8 with 24 attainable
Now its 6.1 with 29 attainable (Was 32 initially).


Chicken or egg - less useable tones means less power, can you see that effect on the bit loading as it matches the above.

Is that the upstream power - if so it's your modem controlling it.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User Chrysalis
(eat-sleep-adslguide) Fri 15-Feb-13 14:31:00
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
you said this last time, the amount of tones in use is the same, I use every tone in the entire 17a range. Except when I had a 90mbit attainable sync, the very last tones werent used as they werent needed. But now they are all used. Its not a static power per tone, those days are history, dsl has advanced since then. since adsl2 power cutback is a feature.

The HG dslams used by openreach allow powermasking to be set individually per line. adebov had the same issue and adsl24 also posted a while back they seen powermasking changed on lines as well.

The dslam most defenitly can control upstream powermasking, its listed in the vectoring documentation that prior to vectoring its CP's primary tool for controlling upstream crosstalk.

BT Infinity 2 Since Dec 2012 - Estimate 65.9/20 - Attainable peak 110/36 - Current Sync 71/20

Edited by Chrysalis (Fri 15-Feb-13 14:33:10)

Standard User yarwell
(sensei) Fri 15-Feb-13 19:37:27
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Re: Possible two routes for line


[re: Chrysalis] [link to this post]
 
how does the DSLAM control upstream power ? I can see how it might send data to the modem but the modem does the transmitting and the DSLAM merely listens to it.

There is still a maximum power per tone, which is what I was driving at, as fixed by the power mask. If the lower speed means less tones, rather than less bits/tone, then there'll be less power. Power cutback is seldom seen in the wild for "optimisation" but a regulatory mask is A Different Thing (tm).

Conversely if the power mask is "in the way" there'll be less SNR per tone and hence less bits.

The ANFP requires upstream power masking per line based on D side length, just like it requires downstream masking based on E side length.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User Chrysalis
(eat-sleep-adslguide) Fri 15-Feb-13 22:42:09
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
well the modem is the device doing the transmitting, but most likely the parameters are sent to the modem during the sync process.

To make this even more interesting, my 36mbit upload attainable bitloading with the highest TX power at 6.6 is also not using all the tones for the upstream, since it had so much excess snrm the tones between 1000 and 1250 werent used. So it was using more power across less tones.

BT Infinity 2 Since Dec 2012 - Estimate 65.9/20 - Attainable peak 110/36 - Current Sync 71/20

Edited by Chrysalis (Fri 15-Feb-13 22:45:27)

Standard User yarwell
(sensei) Sat 16-Feb-13 07:53:53
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Re: Possible two routes for line


[re: Chrysalis] [link to this post]
 
I have seen different strategies used by different kit where they easily meet the required speed like in your upstream case. One modem used a small number of bits per bin across the whole range and another piled lots of bits into the low bins until it met the speed spec.

The first would allow power cutback to be used across the range, the second used less power due to less tones.

With a limit on total power and on power per tone there are many permutations I guess, without throwing "Green DSL" into the pot and getting 80% of achievable speed for 50% of the power or whatever. I don't think we're seeing power cutback used other than on lines at maximum sync, are we ?

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User Chrysalis
(eat-sleep-adslguide) Sat 16-Feb-13 11:11:09
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Re: Possible two routes for line


[re: yarwell] [link to this post]
 
no idea.

Crosstalk can also cause crc errors even without an impact on speed, so it may be there is lines in any given area (maybe my area) that are having stability issues so then power is cutback to reduce crosstalk to manage the errors, maybe not I dont know.

To be fair I havent read documentation anywhere that states CP's use powermasking to manage downstream crosstalk (only upstream) and on downstream to protect adsl services, I just assumed if its used on the upstream it logical its used on the downstream as well. Then I made further assumptions based on what some end users have reported and what I am seeing on my own line. But in the VDSL spec's power can be cutback on individual tones if desired.

An end user eg. is more likely to notice a 15mbit speed drop off to 5mbit than someone on 80mbit drop off to 70mbit. So a CP making choices on who to hinder for the sake of fairness and all that maybe chooses to help the 15mbit user over the 80mbit user. Indeed I havent reported this as a fault, but if I had a 15mbit sync dropoff to 5mbit I would almost certianly be crying about it to tech support on a regular basis.

In terms of crc errors. on the 5.8 power my upstream had about 50% of the downstream crc error rate. On 6.1 its now about 20% with the extra margin, on 6.6 it was extremely low.

To me it looks fairly clearcut my upstream power is been fiddled with, but far less clearcut on the downstream. The downstream could easily be just down to huge crosstalk.

BT Infinity 2 Since Dec 2012 - Estimate 65.9/20 - Attainable peak 110/36 - Current Sync 71/20
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