80/20 Predicted Speeds vs Actual Speeds

Hi Guys,

80/20 was activtaed last night on our broadband and was wondering if you guys could answer a few questions for me.

Here is what the Broadband Wholesale Checker says:
Our test also indicates that your line currently supports a fibre technology with an estimated WBC FTTC Broadband where consumers have received downstream line speed of 55.1Mbps and upstream line speed of 13.2Mbps.

Here is what speedtester.bt.com says:
Download speedachieved during the test was - 44.15 Mbps
For your connection, the acceptable range of speedsis 12 Mbps-46.75 Mbps .
Additional Information:
IP Profile for your line is - 46.75 Mbps

Upload speed achieved during the test was - 6.09Mbps
Additional Information:
Upstream Rate IP profile on your line is - 20 Mbps

Plusnet Profile:
Current line speed: 20 Mb - This seems a little odd??

I was always under the impression that the broadband wholsale checker is usually very conservative in the predicted speeds, but that doesn't appear to be the case.

Does 80/20 FTTC have a 10 day training period? I have read conflicting information on this subject. Is it likely my speed will increase the longer it remains connected?

Don't get me wrong the speed is great, just wonering if we are likely to get a bit more out of it.

I think I'm about 500 meters from the cabinet, maybe less.
Google Maps - Home - FTTC cabinet

Many thanks

Michael.

Edited by deleted (Fri 08-Jun-12 11:58:59)

At 450-500 metres that does seem at little low ... but as both up and down and low there could be a couple of reasons. High attenuation - or high noise levels. Do you actually know that the route you have plotted is the actual cable route? It could be different and there is no easy way to confirm it. It could go 100m past your house before doubling back, or further along the main road before turning onto the estate.

It is unlikely to change by very much in the near future.

We had FTTC installed on Wednesday. There is a similar thread here about speeds which may interest you:

http://forums.thinkbroadband.com/fibre/f/4128489-802...

BTW estimate was 49.9 / 10.9. Just run BT Speedtester which is reporting:

Download: 44.54 Mbps
IP Profile for your line is - 46.81 Mbps

Upload speed achieved during the test was - 6.72Mbps
Upstream Rate IP profile on your line is - 20 Mbps

So we are in a similar situation to you where the upstream is quite a bit lower than predicted. That said the speed is great so really am knit-picking here.

I think the cabling is pretty direct although I am only guessing by looking at the poles and BT covers in the pavement.

I did do a a test at speedtest.net which showed a great improvement on the upload.

Speedtest.net result

The engineer seemed to think it was pretty direct, but I wasn't sure just how much he actually knew. I haven't unlocked my modem yet as I didn't want to disturb the line if a training period was still used.

Michael.

What does the plot look like in Task Manager - Networking when you do a Speedtest.Net and TBB tests? Can you do a screen shot and provide a link to view it at?

I will do one this evening when I get home and report back.

Thanks.

TLE

In reply to a post by TLE:

Plusnet Profile:
Current line speed: 20 Mb - This seems a little odd??

That bit is absolutely correct - don't be tempted to ask them to change it!

In reply to a post by TLE:

That bit is absolutely correct - don't be tempted to ask them to change it!

With ADSL and ADSL2+ it was always matched to the downstream IP profile (if and when they recieved a delta report), I take it this has changed with FTTC 80/20?

In reply to a post by TLE:

With ADSL and ADSL2+ it was always matched to the downstream IP profile (if and when they recieved a delta report), I take it this has changed with FTTC 80/20?

20Mb is a special value that means unrestricted for FTTC, the value is a hangover from ADSL 2+. This will likely be changed at some point at the future, but at the moment, any value other than 20 for an FTTC connection is potentially bad news as it may restrict your speeds.

Thanks for that info kasg.

Not all Plusnet support agents seem to be fully au fait with this yet, so if you ring up and query your speeds there is a danger they will start playing with it.

Ok I have unlocked the modem tonight and got some stats.

Mode VDSL2
Traffic type PTM
DSL synchronization status Up
DSL up time 241

Downstream Upstream
Attainable rate (kbit/s) 48716 17058
SNR margin (dB) 6.3 6.2
Line attenuation (dB) 0 0
Output power (dBmV) 12.7 6.8

Path 0 Path 1
Downstream Upstream Downstream Upstream
Line rate (kbit/s) 47588 16428 0 0
CRC errors 0 0 0 0
FEC errors 5 0 0 0
HEC errors 19 0 0 0

Here are the task manager results:
Speedtest dot net
http://imageshack.us/photo/my-images/707/speedtestdo...

speedtester dot bt dot com
http://imageshack.us/photo/my-images/43/speedtesterb...

Thanks

Michael.

Edited by deleted (Fri 08-Jun-12 22:22:18)

If you want to see and/or show others your stats such as attenuation, error counts etc. you can run telnet commands.

Alternatively, if you are a Windows user, you could use the graphing scripts downloadable from a link in the first post here:-

Huawei HG612 Modem - Stats & Graphs for Windows Users


EDIT:

I'm also with Plusnet & Alex R is very familiar with my "faulty connection" graphs.
(In fact, I'm 100% sure he is sick to death of seeing them now)

Edited by deleted (Sat 09-Jun-12 09:54:06)

although I cant get FTTC yet its interesting that BT can now give me an estimate. If my down speed is really going to hit 66meg would that typically get me 20meg upload?

ADSL

Between 3.5Mb and 8.5Mb
(Estimated speed: 6.0Mb)

Now

FTTC

65.9Mb download
20.0Mb upload

30-September-2012

If you get a downstream sync above 60Mb/s then you are very likely to get the full 20Mb/s upstream sync (throughput will be lower, 17-18Mb/s being a 'pretty good result').

Ok, Here are some more stats from xdslcmd.

# xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 2
Max: Upstream rate = 16395 Kbps, Downstream rate = 46760 Kbps
Path: 0, Upstream rate = 16428 Kbps, Downstream rate = 48511 Kbps
Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3959)
Medley Phase (Final) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3959)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 16395 kbps 46760 kbps
Actual Aggregate Tx Power: 6.8 dBm 12.7 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 5.4 29.7 44.9 N/A 14.5 36.4 56.3
Signal Attenuation(dB): 7.2 28.9 43.8 N/A 14.5 36.4 56.3
SNR Margin(dB): 6.0 6.2 6.2 N/A 5.3 5.3 5.4
TX Power(dBm): -4.1 -13.1 6.3 N/A 9.8 7.8 5.1

Would I be right in thinking that the Line Attenuation figures would seem to indicate that I am actually further away than 500m, more likley 600m?

Ps. Is there a guide to interpreting these figures for the Huawei modem?

Thanks

Michael.

Edited by deleted (Mon 11-Jun-12 10:07:07)

I have just found out that I can get FTTC on my exchange. BTW gives me an estimate of 31.4mb/s down and 5.7mb/s up I am about 600m from the cabinet (via road). Currently I am on a ADSL2+ connection with a d/l line sync of 17mb/s and line attenuation of 18.5db, surely the line attenuation will decrease as the cabinet is about half the distance between me and the exchange. Do the estimates seem correct as I am hoping to get the 80/20 product.

Edited by deleted (Mon 11-Jun-12 16:21:36)

In reply to a post by whosyagamer:

Do the estimates seem correct as I am hoping to get the 80/20 product.

The estimate sounds about right for 600m, with luck you should get a bit more, but you are unlikely to benefit significantly from 80/20.

Edited by kasg (Mon 11-Jun-12 16:46:21)

Not necessarily. There could be some small gauge cabling in the circuit which will have the same effect.

When you are measuring, remember there is the distance from FTTC cabinet to normal cabinet, the possibility of ducts not being the most direct, 7 metres to get up the pole, the extra in the catenary, maybe a loop at the top of the pole, some slack in the ground, the drop from your eaves to the ground floor.

So does the line attenuation decrease if the cabinet is half the distance from the exchange & does it also effect the SNR ratio as well?

I know my exact line length from the exchange to my home is 1200m (926m as the crow flies) as I have seen it on BT's systems as I am an ex Openreach engineer. From using Google Earth I have estimated the distance from my home to the cabinet of about 600m.

In reply to a post by whosyagamer:

So does the line attenuation decrease if the cabinet is half the distance from the exchange & does it also effect the SNR ratio as well?

I know my exact line length from the exchange to my home is 1200m (926m as the crow flies) as I have seen it on BT's systems as I am an ex Openreach engineer. From using Google Earth I have estimated the distance from my home to the cabinet of about 600m.

Technician or Engineer? An Engineer would know the answer!

The answer is maybe ... but there are many factors that could affect it. Are you talking about attenuation at DC or DSL frequencies? Is the cable exactly the same gauge? Even the same gauge cable has a maximum and minimum size and if at the extremes there could be a difference. The capacitance of the line and proximity of other lines can affect the AC impedance and thus attenuation.

I was a DSL frames engineer.

The line attenuation & SNR is from my DSL router information currently, that is why I am asking does it get better.

But for FTTC I have seen pictures on this forum with higher line attenuation from the test equipment when it is getting installed.

http://tinypic.com/view.php?pic=crcw3&s=6

Edited by deleted (Mon 11-Jun-12 17:54:02)

If your ADSL attenuation was say 50dB then if you had ADSL from the cabinet (at half distance) then your attenuation would drop to around 25dB.

The attenuation figures are an "average" of attenuations at various frequencies or at a specific 300 kHz (on ADSL)

However, as VDSL uses a frequency band a lot greater than ADSL and the attenuation of higher frequencies is a lot greater the "average" attenuation will be greater than you have for ADSL.

My ADSL attenuation was about 45dB but and the distance from house to cabinet is about 1/5 or 1/6 of distance to the exchange. My ADSL attenuation if supplied from the cabinet would be around 8dB but in reality the VDSL attenuation on the JDSU is around just under 20dB. Again, the modem reports attenuation in each of the Up and Down bands.

I am on an ADSL2+ connection with 18.5db line attenuation and it can go down as far as 16db on a good day.

All I want to find out is would it be worth going for an 80/20 FTTC product when the estimate is 31.4mb/s & 5.7mb/s up as I am taking these with a pinch of salt as they are estimates.

The new cabinets only got activated yesterday.

Edited by deleted (Mon 11-Jun-12 18:13:00)

The BT speedtester I've found rather random for FTTC - so check by other means too. I've had it tell me it is seeing 20M down and 2M up when immediately after I can open connections to elsewhere and happily push and pull close to the maximum expected from an 80/20 line (especially if I test using a multi-stream application such as transfers via bittorrent).

BT's "beta" tester for faster lines does better, returning 77.10 and 6.42 just now which is about right for downstream but way off for upstream.

The downstream figure you get from the test is close to what they thing your line is capable of though, so that is unlikely to be an issue with the tester. The estimate from the wholesale checker is an estimate based on lines in the area (and sometimes a finger-in-the-air guess if none of those lines has FTTC active) - it doesn't read from your specific line. For mine it still says 62.5 downstream when I've been happily running at as close to the 80 as you can get since upgrading some weeks ago. Also you could be unlucky geographically and find that the line between the cab and you does not follow the best-case-by-road route to get to your premises.

these are my stats... bout 400 - 600 meters away with some ali

Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 15765 Kbps, Downstream rate = 47424 Kbps
Path: 0, Upstream rate = 15587 Kbps, Downstream rate = 50125 Kbps

Discovery Phase (Initial) Band Plan
US: (0,95) (880,1195) (1984,2771)
DS: (32,859) (1216,1959) (2792,4083)
Medley Phase (Final) Band Plan
US: (0,95) (880,1195) (1984,2771)
DS: (32,859) (1216,1959)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 15765 kbps 47424 kbps
Actual Aggregate Tx Power: 6.8 dBm 11.9 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 2.8 35.2 53.6 N/A 16.5 44.7 66.2

Signal Attenuation(dB): 2.7 35.1 53.3 N/A 16.5 44.7 N/A

SNR Margin(dB): 6.1 6.1 6.3 N/A 4.6 4.6 N/A

TX Power(dBm): -4.4 -7.1 6.3 N/A 10.0 7.4 N/A

# xdslcmd info --show
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 15771 Kbps, Downstream rate = 47424 Kbps
Path: 0, Upstream rate = 15587 Kbps, Downstream rate = 50125 Kbps

Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 4.6 6.2
Attn(dB): 0.0 0.0
Pwr(dBm): 11.9 6.8

Difficult to say ... at 600 metres I would expect more than 31Mbps but there may be good reason for that estimate.

One thin which raises a questions is that your attenuation varies from 18.5 to 16 dB ... that is a lot of variation on a line especially a shortish one. If the modem only reports in 0.5 dB steps then seeing 18.5 and 18.0 (max of 0.5) is normal, or if it is in 0.1 dB steps a difference of maybe 0.2dB but 2.5db is massive and suggests a possible problem.

Can you get Router Stats Lite - use the CUSTOM setting and make it read attenuation rather than SNR - the graph annotation will be wrong but it will show the attenuation varying against time.

Line Attenuation(dB): 5.4 29.7 44.9 N/A 14.5 36.4 56.3

I realise what Line Attenuation is, but why are there multiple values for this now, is this to do with the different frequencies?

They are for the different blocks of frequencies used in each direction.

Up0, Up1, Up2, Up3 (n/a), Down1, Down2, Down3

The band order is: U0, D1, U1, D2, U2, D3, U3

Ok, so finally I had FTTC installed yesterday and as I said initially the WBC checker estimated I would only get 31 down & 5.7 up. I am on the 80/20 profile and 600m from the cabinet my line sync's at 69mb/s down & 20mb/s up so the distance isn't affecting it much. My download tests give me 65mb/s down and 12mb/s up using speedtest.net.

http://speedtest.net/result/2020835870.png

That's a huge increase on ADSL2+ when I synced at only 17mb/s down & 1mb/s up.

In reply to a post by whosyagamer:

That's a huge increase on ADSL2+ when I synced at only 17mb/s down & 1mb/s up.

Only 17Mb/s

Very few people can say that (I used to get 21Mb/s before moving but never said "only")

In reply to a post by whosyagamer:

My download tests give me 65mb/s down and 12mb/s up using speedtest.net.

It will be interesting to see if that holds at that distance. After a couple of days, DLM can strike!

I will keep an eye on it, as I was the very 1st one made live on the new cabinet yesterday as the exchange only went live officially this Monday. The speed hasn't changed today at all.

Nice increase of an extra 10mb/s on Thursdays result.

http://speedtest.net/result/2028145205.png