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Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

mgillespie
Grafter
Posts: 222
Registered: 08-04-2007

Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

Been very happy since my ADSL2 upgrade, aside from one persistent problem.  When my router reboots, it gets given a totally outragous profile, one that is totally useless, the error rate is sky high, with almost every packed arriving corrupted.
I then reboot my router and it gets a far more realistic profile.  Is there any way to manually "cap" thew profile?
26 REPLIES
Community Veteran
Posts: 19,099
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Registered: 31-08-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

When your Router reboots ......... Can you say why or under what circumstances it reboots?
mgillespie
Grafter
Posts: 222
Registered: 08-04-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

Because the builder needed fo turn the leccy off, because I updated the firmware, because of a powercut...

Does it matter?  It's an annoyance that my broadband is useless until I reboot it again because of the silly profile it's given
Community Veteran
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Registered: 15-06-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

Have you tried resynching the router in the late evening and leaving it connected
mgillespie
Grafter
Posts: 222
Registered: 08-04-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

Yes, and everything is super, until the router is reset for whatever reason, and then it just gets a silly profile thats 1MBit/sec that's higher than usual and totally unattainable, resulting in 90%+ packetloss.
Community Veteran
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Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

Quote from: ClashcityRocker
Because the builder needed fo turn the leccy off, because I updated the firmware, because of a powercut...
Does it matter?  It's an annoyance that my broadband is useless until I reboot it again because of the silly profile it's given

Yes it mattered, and as you may not understand how ADSL works, it could have been you rebooting because of line drops or some other fault affecting your noise margin. We don't know what modem/router you have, how old it is, or any line stats or BT speedtest results etc. Have you tried an alternative modem/router and filter at the Test Socket to try and eliminate those possibilities?
If you are wanting a profile to be fixed to some "nice" value, in fact any value, the short answer is no.
As you seem unwilling to give any information, you are probably best to raise a fault and wait for a member of the Plusnet team to look at your account rather than other forum members trying to assist you.
mgillespie
Grafter
Posts: 222
Registered: 08-04-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

I'm more than happy to give whatever info is needed.
It's a draytek 2820, and the line is very stable (and always has been) except when the router is initially started, and it gets a totally unrealistic profile.  I admit I don't know how these profiles are worked out, and what kind of history they have, but I know that my line is totally incapable of supporting 17715947, and the 1MB downloads from fast severs are taking over 3 hours to download and my router error rate is going bananas, yet when I restarted it gets 16854532 and the speed is brilliant and there is virtually no error packets.
Community Veteran
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Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

Basically I think that your default noise margin is 3dB - you can check this by looking at the margin immediately after a router resync.
I think what you are seeing is that very quickly - probably in the evening - the noise margin drops to about 1dB and the errors kill your connection.
A resync at that point will give a slightly lower speed with the 3dB noise margin.
The problem is probably related to the router (I have seen this before) hanging onto the connection and not resynching when the error rate is too high
If Plusnet manage to force the default noise margin to 6dB your speed will drop a lot more than 1,000kbps
Community Veteran
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Registered: 31-08-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

Going on from what Jim has said, I believe it's possible to get the Target SNRM minimum set. There is another current thread on here with a similar issue. http://community.plus.net/forum/index.php/topic,104227.0.html
If you have the latest firmware (a quick cursory search indicated it fixed a few bugs - didn't look at the detail) then I'd go for trying another modem/router and filter just to test if the same occurs.
It might be worth you posting the Modem/Router Line Stats from when it's ok and then again next time it isn't to see if the differences reveal anything.
Edit: add thread link
mgillespie
Grafter
Posts: 222
Registered: 08-04-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

Well things were on a goslow, a reboot and it's sync'd slighty lower, but it's 10x quicker downloading the same file it was downloading before I rebooted.
Current GOOD  are:

 --------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
  Running Mode            : ADSL2+(G.992.5)       State                : SHOWTIME
  DS Actual Rate          : 16997087 bps   US Actual Rate       :   888888 bps
  DS Attainable Rate      : 18592000 bps   US Attainable Rate   :   888000 bps
  DS Path Mode            :  Interleave    US Path Mode         :  Interleave
  DS Interleave Depth     :       96       US Interleave Depth  :        8
  NE Current Attenuation  :       27 dB    Cur SNR Margin       :        3  dB
  DS actual PSD           :    20. 3 dB    US actual PSD        :    11. 8   dB
  ADSL Firmware Version   : 2471201_A
 -------------------------------- ATU-C Info ---------------------------------
  Far Current Attenuation :       15 dB    Far SNR Margin       :       13  dB
  CO ITU Version[0]       : 00004946       CO ITU Version[1]    : 0000544e
  DSLAM CHIPSET VENDOR    : < IFTN >


I will wait for it to go wrong again, and repeat the above.
Community Veteran
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Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

After it reconnects and starts giving loads of errors, how long do you leave it before forcing another reconnect? I'm wondering if you are not leaving it long enough for the DLM to realise 3db isn't enough and raising the target to 6db.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
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Mobile: iD mobile (£4/month)
mgillespie
Grafter
Posts: 222
Registered: 08-04-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

OK, on a MAJOR go-slow this evening, my ADSL2+ is behaving like a 56k modem...  It's totally unusable..
Router Stats: (note the higher than normal sync speed)

--------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
  Running Mode            : ADSL2+(G.992.5)      State                : SHOWTIME
  DS Actual Rate          : 17539622 bps  US Actual Rate      :  888888 bps
  DS Attainable Rate      : 17192000 bps  US Attainable Rate  :  888000 bps
  DS Path Mode            :  Interleave    US Path Mode        :  Interleave
  DS Interleave Depth    :      320      US Interleave Depth  :        8
  NE Current Attenuation  :      32 dB    Cur SNR Margin      :        2  dB
  DS actual PSD          :    20. 2 dB    US actual PSD        :    12. 3  dB
  ADSL Firmware Version  : 232201_A
  -------------------------------- ATU-C Info ---------------------------------
  Far Current Attenuation :      15 dB    Far SNR Margin      :      14  dB
  CO ITU Version[0]      : 00004946      CO ITU Version[1]    : 0000544e
  DSLAM CHIPSET VENDOR    : < IFTN >

Speed test:

Going to reboot the router, and pretty sure it will get something that's a MUCH better sync rate, and something that instantly improves my speeds.
mgillespie
Grafter
Posts: 222
Registered: 08-04-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

And as predicted, a reboot, I get slower sync speed and my line is happy again.

  --------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
  Running Mode            : ADSL2+(G.992.5)      State                : SHOWTIME
  DS Actual Rate          : 17115947 bps  US Actual Rate      :  888888 bps
  DS Attainable Rate      : 17152000 bps  US Attainable Rate  :  888000 bps
  DS Path Mode            :  Interleave    US Path Mode        :  Interleave
  DS Interleave Depth    :      96      US Interleave Depth  :        8
  NE Current Attenuation  :      32 dB    Cur SNR Margin      :        3  dB
  DS actual PSD          :    20. 1 dB    US actual PSD        :    11. 7  dB
  ADSL Firmware Version  : 232201_A
  -------------------------------- ATU-C Info ---------------------------------
  Far Current Attenuation :      15 dB    Far SNR Margin      :      13  dB
  CO ITU Version[0]      : 00004946      CO ITU Version[1]    : 0000544e
  DSLAM CHIPSET VENDOR    : < IFTN >

mgillespie
Grafter
Posts: 222
Registered: 08-04-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

How do I go about getting this problem diagnosed?  It only kicks off it seems when my router disconnects after a lenghy period connected (today the ADSL disconnected about 4 hours ago, I guess BT are tinkering again).
Plusnet Help Team
Plusnet Help Team
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Registered: 27-04-2007

Re: Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

Quote
How do I go about getting this problem diagnosed?

I'd be testing this with a different router next to see if the level of errors after a resync is any different.
If this post resolved your issue please click the 'This fixed my problem' button
 Adam Walker
 Plusnet Help Team