Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: S.Stephenson on June 02, 2015, 02:50:55 AM
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After looking at many line status with similar line attenuation my line seems to be performing quite badly.
When looking into cross talk I hear the typical loss is around 10-15mbit, I will go through what I have experienced with crosstalk.
Shown is a speed test from late 2013, at this time I recall having a max attainable around 85000.
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fs3.postimg.org%2Fqk03ht74j%2FUntitled2.png&hash=80e52b6441b72802cde86da04e8e7cd85872e9b1)
However within the last year the line has carried on dropping, with different periods of syncs.
1. Kept around 73mbit with drops to 68mbit
2. Around 70mbit drops to 64mbit
3. Around 64mbit
At present I can maintain 60mbit, but the issue I have is the upload speed dropping to 13mbit.
Also seeing as I'm on an ECI cabinet I hold no hope for vectoring, its just frustrating to lose so much speed.
I have seen people with lower download syncs but still having 20mbit upload speeds, as well as better speeds on much higher attenuation, so is the low upload speed normal?
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fs4.postimg.org%2F63mkcx2d9%2FUntitled.png&hash=76f74f4cf0e01e8c66fb72f087854ea657c3df0a)
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I am in a similar position I had attainable in the high 90's but I am now in the mid 50's down. Still got 20 upload though. Eci cabinet, hg612 modem so I can get stats for when it drops another huge chunk - hopefully never as I am getting close to 50% loss due to crosstalk.
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ISTR a rule of thumb about the max attainable rising with increasing interleaving and vice-versa.
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Ive lost circa 30Mbps from my max downstream to crosstalk since Aug 2013. Only just hanging on to 80/20 due to the router Im using.
ISTR a rule of thumb about the max attainable rising with increasing interleaving and vice-versa.
It does seem to go skewy when Interleaving is applied - or more correctly when Error Correction is applied. I think it may have something to do with the overheads needed to transmit redundant data for RS encoding.
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I went from 110/36 attaianable to below 50 and about 21 up.
So I lost over 50% of my attainable speeds. I remember a certian person on plusnet try to tell me loss of attinable is irrelevant, it isnt as it shows how bad the local loop's are to lose well above average crosstalk (40% from alcatel testing is considered worst case scenario).
The good news is I failed the GEA test as I lost a chunk in one go (for a 3rd time) which made me fail on the basis of a 25% loss of sync speed in a short time, then I got a pair swap and am back to low 70s, still over 30mbit down, but at least close to the service limit now.
In regards to vectoring on ECI, given the rumours from ignition and the fact openreach look like they wont even get g.inp properly working, it doesnt bode well.
I know he may come here and slap me as he says they all clever people, but it smacks of incompetence how the ECI situation has came about. How short sighted can someone be to install obselete equipment at time of rollout.
Also given how they even managed to mess up something simple like g.inp, (yes it is simple) they probably will be now scared to try vectoring for a while, they created a mess with mixing modems with wrong chipsets and allowing isp's to use their own modems. all recipes for disaster.
To the guy who has low upstream speed, you could be unlucky and an asus modem user has overridden their UPBO, and openreach not been clever enough to detect someone is breaching the openreach guidelines and not been disconnected for it. Who knows.
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Where are these points of crosstalk?
Neighbours having FTTC?
Being on a full line card at the cabinet?
The ironic thing is that in my area DSL was 1-2mbit and as a result uptake is very high, but because of this speeds are dropping and I wouldn't be surprised if a few people far away from the cabinet have been kicked off as a result.
One of the things that annoys me is the shiny new BDUK Hawaii cabinet across the road serving like 50 people, weras i'm stuck with an ECI serving ~300 people with strong uptake.
Basically if you had bad DSL speeds you are also going to have bad vDSL speeds due to increased uptake.
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One of the things that annoys me is the shiny new BDUK Hawaii cabinet across the road serving like 50 people, weras i'm stuck with an ECI serving ~300 people with strong uptake.
An ECI cabinet can serve 256 lines in total. (The ECI Hi-FOCuS M41 can take a maximum of 4 line cards, each with 64 ports.)
A "small" Huawei cabinet can serve 128 lines in total. (The Huawei SmartAX MA5616T can take a maximum of 4 line cards, each with 32 ports.)
A "big" Huawei cabinet can serve 288 lines in total. (The Huawei SmartAX MA5603T can take a maximum of 6 line cards, each with 48 ports.)
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The good news is I failed the GEA test as I lost a chunk in one go (for a 3rd time) which made me fail on the basis of a 25% loss of sync speed in a short time, then I got a pair swap and am back to low 70s, still over 30mbit down, but at least close to the service limit now.
I am beginning to think I should have followed my drop in speed up but at the time the consensus was crosstalk and nothing could be done.
According to my current stats I am still on fast path and my downstream is a rock solid 6-6.5db and my upload 5.5db-6.5db depending on time of day.
Should I try to do anything as compared to original attainable I have lost approx 40%. BT checker has dropped speed and I an at the low end of scale.
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I stopped monitoring my connection for a bit and have just restarted... I've lost 4dB off my DS margin taking my attainable from 125Mb/s down to 110Mb/s.
That seems to be inline with what you've suggested? :)
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I stopped monitoring my connection for a bit and have just restarted... I've lost 4dB off my DS margin taking my attainable from 125Mb/s down to 110Mb/s.
That seems to be inline with what you've suggested? :)
Yes I can't be sure of my original max attainable as I was not monitoring. I was first on cab and started monitoring after a few weeks at around 95Mbs so may have had over 100Mbs now down to 55Mbs so approaching half lost. Upstream still at 20Mbs which is good,