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Standard User deleted
(deleted) Wed 30-Nov-11 21:54:11
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
In reply to a post by MrGrumpy:
your line looks very similar too mine

# xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 12014 Kbps, Downstream rate = 50444 Kbps
Path: 0, Upstream rate = 10000 Kbps, Downstream rate = 39996 Kbps

Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3939)
Medley Phase (Final) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3939)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 12014 kbps 50444 kbps
Actual Aggregate Tx Power: 6.6 dBm 11.8 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 5.6 31.4 45.9 N/A 15.3 38.9 59.7
Signal Attenuation(dB): 7.3 30.6 44.7 N/A 15.3 38.9 59.7
SNR Margin(dB): 7.7 7.7 7.7 N/A 7.0 7.1 7.4
TX Power(dBm): -3.9 -13.3 6.3 N/A 8.1 7.9 4.3


thing is it used to only sync at approx 30000kbps downstream and 8000kbps up


Looks like they don't apply the same band settings to all cabinets as mine looks like this:

# xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 19805 Kbps, Downstream rate = 67068 Kbps
Path: 0, Upstream rate = 9995 Kbps, Downstream rate = 39998 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) (2792,4083)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 19805 kbps 67068 kbps
Actual Aggregate Tx Power: 6.5 dBm 12.8 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 1.0 24.0 37.0 N/A 12.7 30.3 50.0
Signal Attenuation(dB): 0.9 23.8 36.9 N/A 12.7 30.3 50.0
SNR Margin(dB): 14.3 13.3 12.9 N/A 14.6 14.8 14.6
TX Power(dBm): -4.9 -20.3 6.2 N/A 11.5 7.4 -6.3

Before the update I had a u/s attainable of 15800 and d/s 41800.

The line is approx 600m ti the cab and 6km to the exchange.
Standard User deleted
(deleted) Wed 30-Nov-11 23:13:55
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
Hi rhino7

In reply to a post by rhino7:
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) (2792,4083)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 19805 kbps 67068 kbps
Actual Aggregate Tx Power: 6.5 dBm 12.8 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 1.0 24.0 37.0 N/A 12.7 30.3 50.0
Signal Attenuation(dB): 0.9 23.8 36.9 N/A 12.7 30.3 50.0
SNR Margin(dB): 14.3 13.3 12.9 N/A 14.6 14.8 14.6
TX Power(dBm): -4.9 -20.3 6.2 N/A 11.5 7.4 -6.3



That's the first one that has been noticed as being a different band plan.

Just to confirm, does it still show as profile 17a?

(xdslcmd info --show)


Paul.
Standard User deleted
(deleted) Thu 01-Dec-11 02:09:36
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
Those are some very different boundaries to the US and DS plans - particularly the top of the last DS band.

My line is also 600 metres from the cabinet, but our cabinet is only 1.5km from the exchange. My boundaries are the same as MrGrumpy.

There is a factor to the cabinets that is known to change, based on the distance that the cabinet is from the exchange: the transmission power maps.

The maps are meant to ensure that the cabinet's VDSL transmissions do not swamp the exchange's ADSL(2+) transmissions. This means that cabinets closer to an exchange can transmit at slightly higher levels (because the ADSL signals are still high) but must take care over a wider frequency range. The cabinets further away are restricted to lower power levels, but over a smaller range (because the ADSL signals will be lower, but some of the higher frequencies will now be unusable that far out)

I wonder if the changes to these power maps cause the differences to the US/DS boundaries? Channel 868 is around 3.7MHz, so is way above the ADSL frequencies. So maybe not...


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Standard User deleted
(deleted) Thu 01-Dec-11 12:22:01
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
In reply to a post by Bald_Eagle1:
Hi rhino7

In reply to a post by rhino7:
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) (2792,4083)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 19805 kbps 67068 kbps
Actual Aggregate Tx Power: 6.5 dBm 12.8 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 1.0 24.0 37.0 N/A 12.7 30.3 50.0
Signal Attenuation(dB): 0.9 23.8 36.9 N/A 12.7 30.3 50.0
SNR Margin(dB): 14.3 13.3 12.9 N/A 14.6 14.8 14.6
TX Power(dBm): -4.9 -20.3 6.2 N/A 11.5 7.4 -6.3



That's the first one that has been noticed as being a different band plan.

Just to confirm, does it still show as profile 17a?

(xdslcmd info --show)


Paul.


Hi Paul,

The modem definitely shows profile 17a. I checked that via the telnet interface when I noticed the increase in the attainable upload and download speeds in the web interface.

Dave.
Standard User deleted
(deleted) Thu 01-Dec-11 12:37:37
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
In reply to a post by WWWombat:
Those are some very different boundaries to the US and DS plans - particularly the top of the last DS band.

My line is also 600 metres from the cabinet, but our cabinet is only 1.5km from the exchange. My boundaries are the same as MrGrumpy.

There is a factor to the cabinets that is known to change, based on the distance that the cabinet is from the exchange: the transmission power maps.

The maps are meant to ensure that the cabinet's VDSL transmissions do not swamp the exchange's ADSL(2+) transmissions. This means that cabinets closer to an exchange can transmit at slightly higher levels (because the ADSL signals are still high) but must take care over a wider frequency range. The cabinets further away are restricted to lower power levels, but over a smaller range (because the ADSL signals will be lower, but some of the higher frequencies will now be unusable that far out)

I wonder if the changes to these power maps cause the differences to the US/DS boundaries? Channel 868 is around 3.7MHz, so is way above the ADSL frequencies. So maybe not...


What are your before and after attainable values? Mine went from 43/15 to 68/20 (or thereabouts). It would be interesting to see your values against mine as your line is a similar length from the cab. It was the fact that it "only" went up to 68 meg that made me look at the band allocation as I'd noticed that other people reported much better improvements in download speed but not always very much improvement in the upload speed (or even a reduction).
Standard User deleted
(deleted) Thu 01-Dec-11 21:44:12
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
In reply to a post by rhino7:
What are your before and after attainable values? Mine went from 43/15 to 68/20 (or thereabouts). It would be interesting to see your values against mine as your line is a similar length from the cab. It was the fact that it "only" went up to 68 meg that made me look at the band allocation as I'd noticed that other people reported much better improvements in download speed but not always very much improvement in the upload speed (or even a reduction).


I don't know the 'before' attainable value, as I didn't unlock the modem until after we went to profile 17a. However, while we synced with a 38717 profile initially, DLM didn't like the error rates on the line, and wiped 4Mbps off us (profile of 34799, download speeds of 33.5Mbps, so i assume a sync of roughly 36Mbps) and turned interleaving on. Upstream was always 10Mbps, so I can't tell the max attainable there. I'll therefore guess that our downstream attainable was the same as actual - around 36 Mbps.

Today, our attainable speeds are 61/17. That is with interleaving turned on - DLM seems to have changed our settings at the weekend. Before the weekend (but still on profile 17a) our attainable speeds were 59/17.
Standard User deleted
(deleted) Tue 17-Jan-12 09:11:14
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
When I was on 8c my us attainable rate was about 14000 syncing at 10000. When it switched to 17a my us sync dropped to 5000 ds stayed at 40000. My current stats are:-

# /bin/xdslcmd info --pbParams
/bin/xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 2
Max: Upstream rate = 7164 Kbps, Downstream rate = 50208 Kbps
Path: 0, Upstream rate = 6739 Kbps, Downstream rate = 39996 Kbps

Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3939)
Medley Phase (Final) Band Plan
US: (0,95) (868,1207)
DS: (32,859) (1216,1963)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 7164 kbps 50208 kbps
Actual Aggregate Tx Power: - 4.8 dBm 12.5 dBm
=========================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 6.4 39.8 54.8 N/A 17.7 49.0 69.9
Signal Attenuation(dB): 6.9 38.5 N/A N/A 17.7 49.0 N/A
SNR Margin(dB): 6.7 6.9 N/A N/A 6.9 7.4 N/A
TX Power(dBm): -15.7 -5.2 N/A N/A 10.8 7.9 N/A

My us has gone up a bit after badgering BT. Openreach are not interested. My line length is about 1300m
Standard User deleted
(deleted) Tue 17-Jan-12 17:55:55
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
Hi Hunter59,

In reply to a post by Hunter59:
When I was on 8c my us attainable rate was about 14000 syncing at 10000. When it switched to 17a my us sync dropped to 5000 ds stayed at 40000.

If your line length really is 1300m, you don't appear to be doing too badly (in comparison to my 800m to 1000m connection).
You are actually achieving higher speeds, with lower attenuation levels than my connection.

How accurate would you say your estimated 1300m length is?

It appears that all the 17a band plans are being detected at Discovery Phase (Initial) Band Plan for your connection, but they are not all actually being used at Medley Phase (Final) Band Plan

Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3939)
Medley Phase (Final) Band Plan
US: (0,95) (868,1207)
DS: (32,859) (1216,1963)


It would appear that your attenuation levels are simply too high to make use of the higher frequencies of the higher Band Plans

VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 7164 kbps 50208 kbps
Actual Aggregate Tx Power: - 4.8 dBm 12.5 dBm
=========================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 6.4 39.8 54.8 N/A 17.7 49.0 69.9
Signal Attenuation(dB): 6.9 38.5 N/A N/A 17.7 49.0 N/A
SNR Margin(dB): 6.7 6.9 N/A N/A 6.9 7.4 N/A
TX Power(dBm): -15.7 -5.2 N/A N/A 10.8 7.9 N/A


These are my current stats:-

Text
1
23
45
67
89
1011
1213
1415
1617
1819
2021
22
# xdslcmd info --pbParams 
xdslcmd: ADSL driver and PHY statusStatus: Showtime
Retrain Reason: 1Max:    Upstream rate = 6026 Kbps, Downstream rate = 30968 Kbps
Path:   0, Upstream rate = 5840 Kbps, Downstream rate = 23242 Kbps 
Discovery Phase (Initial) Band PlanUS: (0,95) (868,1207) (1972,2783) 
DS: (32,859) (1216,1963) (2792,3939) Medley Phase (Final) Band Plan
US: (0,95) (868,1207) DS: (32,859) (1216,1963) 
       VDSL Port Details       Upstream        DownstreamAttainable Net Data Rate:       6026 kbps         30968 kbps
Actual Aggregate Tx Power:        6.3 dBm          12.1 dBm============================================================================
  VDSL Band Status        U0      U1      U2      U3      D1      D2      D3  Line Attenuation(dB):  8.6     53.0    63.9     N/A    21.9    63.2    0.1    
Signal Attenuation(dB):  14.1    52.0     N/A     N/A    21.9    63.2     N/A           SNR Margin(dB):  6.5     6.7      N/A     N/A    9.4     9.3      N/A   
         TX Power(dBm): -4.4     5.8      N/A     N/A    11.1    5.3      N/A


My us has gone up a bit after badgering BT. Openreach are not interested. My line length is about 1300m


The slight lowering of US rates appears quite common with the switch from 8c to 17a, usually with a slight increase in DS Rates (currently capped at 40Mb).

Do you recall your DS Attainable rate for 8c, as a comparison with the current Attainable Rate for 17a?


Paul.
Standard User deleted
(deleted) Wed 18-Jan-12 09:58:40
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
Hello Paul,

The 1300m is measured using the website "where's the path" (http://wtp2.appspot.com). It is actually 1100-1300 depending on cable route.

The most significant thing I think is my US transmit power, it�s pitiful, As yet I have seen nobody else�s stats with a negative aggregate. I think that is cause of the reduced US rate.

My US rate hasn't lowered slightly, it has halved.

I think my original DS attainable rate was about 42000. It�s gone up quite a bit with 17a.

Steve
Standard User deleted
(deleted) Wed 18-Jan-12 10:33:47
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Re: Profile 17a - U/S worse?


[re: deleted] [link to this post]
 
Hi Steve,

It might be interesting to see some graphs of your current bit-loading/SNR/QLN levels etc. that may just help to identify the problem area(s).

If you are a Windows user, the tools to generate such graphs can be downloaded via the "Huawei HG612 graphing scripts" link in this TBB post:-

Profile Steps

e.g. these are my recent snapshot graphs:-

Recent snapshot graphs


If you have any previous logs (preferably generated by PuTTy), you could also graph previous stats for comparison purposes.

Getting your ISP/BT to do anything about it would be a whole different ball game though.


Did your US rate deteriorate IMMEDIATELY on being switched from 8c to 17a?

Paul.
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