 BobTheVeg
join:2004-09-05 Montreal, QC
| Need help/tips about DSL connection speed
 Before They Fixed the Problem |  After They Fixed the Problem |  DMT Tweaks |
Hi,
I recently had trouble with my connection ( getting disconnected very frequently ). I called my ISP ( aei.ca ) and they told me that Bell would handle it and verify my line. A day after I got a call from both Bell and aei. Bell said that there was indeed a problem and that it was fixed. Aei called and asked if the problem was solved and they did fix the connection problem.
This problem never happened to me in the last 4 years I have been with aei.
Now I am facing a new problem and it is my connection speed.
I am using a GNet BB0060B. Model: Viking H/W Version: 810012 S/W Version: VIK-1.38.030917a
My connection profile seems to have changed. I am wondering if I can tweak it back as it was before or there is nothing I can do.
I could not find any information on those: RValue, SValue, DValue
I would like to know if this information is good and if I can improve it: Local Tx Power: 12.13 dB Remote Tx Power: 8.11 dB Local Line Atten.: 35.0 dB Remote Line Atten.: 16.0 dB Local SNR Margin: 17.5 dB Remote SNR Margin: 6.0 dB
The DMT screen shows that I could change: - lower the Tx Attun - the bits per bin - the coding gain - ec fdm mode - up/down bin allocation
I have no idea what to adjust. |
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  McSummation Mmmm, Zeebas Are Tastee. Premium,MVM join:2003-08-13 Round Rock, TX | It looks like they "fixed" your problem by dropping your sync speed. You might want to start by calling them and asking why they did that instead of fixing what ever it was that was wrong. |
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  sashwa Pixie Cat Crunchin' n Foldin' Premium,Mod join:2001-01-29 Alcatraz clubs:  1 edit | reply to BobTheVeg Let's get you moved over to our Canadian Broadband Forum for some help.
Good luck. |
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  Bicephale
join:2005-09-24
·TekSavvy Solutions..
| reply to BobTheVeg Hi,
I use a GNet BB0060B as well so i wrote this for the GNet owners:
 GNet Tweaking, Bicephale, 2008-Feb-18
Considering you're now on a 2496/640 Kbps profile, try:
"max. Bits/Bin" = 14 "UpStream (Tx) Bins" = 8 (Start), 24 (End) "DownStream (Rx) Bins" = 36 (Start), 192 (End) "Coding Gain" = 7
Once this is done you'll need to capture 24 h CRC Error rate curves in order to see if it's reasonable to ask AEI for a better profile... By the way, Bell didn't "fix" much that i could see! Your "Remote SNR Margin" remains too close to 6 dB and that's the problem they had to fix...
Oh, one other thing: DON'T FLASH YOUR GNET BB0060B OR YOU MIGHT END UP READING THIS SORT OF THREAD:

Now you've been warned!

Finally, i suspect you may have a wiring issue so i'd like to know if you can deal with it: house wiring...
I also wrote something in order to help a bit with that:
 The customer's own wiring, Bicephale, 2007-Jun-13
The objective is to turn as much red/purple into green as you can, so that in return your CRC Error rate and RCO figures improve - the later being available only through your ISP using Bell's resources... |
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 BobTheVeg
join:2004-09-05 Montreal, QC
| I was looking for something like this: »www.wilcominc.net/Item.cfm?ProdID=35
To centralize my home wiring. Is there a good online shop where I can find comparable product in Canada.
I also tryed to set my GNet BB0060B to: "max. Bits/Bin" = 14 "UpStream (Tx) Bins" = 8 (Start), 24 (End) "DownStream (Rx) Bins" = 36 (Start), 192 (End) "Coding Gain" = 7
But I am facing the problem that in order to be able to make my router connect with a PPPoE connection I must reboot the DSL with default configuration otherwise my router will never connect. Doing so, I lose the configuration.
I assume that I must have a COM1 cable to use the console in order to apply configurations. |
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  Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Hi again,
It isn't clear if you have an NID outside, if so then i doubt you'll be able to fit the "Wilcom PS-15 ADSL2+ Wall-mount POTS Splitter" inside of it. On the other hand, installation of a POTS Splitter inside some NID should be done by the phone company's own people.

The tweaks i suggested won't work unless you click on the [Apply] button and then the [DSL Resync], or preferably, the [Reboot + DSL Resync] button - which implies that the GNet BB0060B would be working as a MoDem/Router (in stand-alone mode)... It's quite possible you'd be able to use 'DMT v2.20' in combination with this DSL device set to "Bridge" (aka "Dumb MoDem") mode via a custom RJ-45 to DB-9 serial RS-232 adaptor cable but i never bothered to try so you'll be the 1st. Welcome to the pioneer club!

As you may have noticed, 'DMT' does also support COM1'.
If this fails, the only alternative would be to remove the router and to switch the BB0060B to MoDem/Router mode. |
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  Bicephale
join:2005-09-24 | reply to BobTheVeg Oh, and don't forget to try the [Refresh] button when the 'DMT v2.20' readings don't seem to make sense!... |
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 BobTheVeg
join:2004-09-05 Montreal, QC
| reply to Bicephale I guess I am now part of the pioneer club !
I managed to build my own rs-232c cable and I can connect with DMT/change settings while using my ipCop router for PPPoE dial.
I'll have results in 24h. |
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  Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Wow! That's a 1st all right, especially with a GNet!!!
Now there's a very good reason to like console ports!
Handy, insn't it?!... Sincere congratulations, really!
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 BobTheVeg
join:2004-09-05 Montreal, QC | reply to BobTheVeg Here is some test I ran before and after. My connection was "fixed" during the 2008-05-22nd.
»/testhistory/1071579/5940e
I can clearly see that I received a 30ms ping increase. |
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 BobTheVeg
join:2004-09-05 Montreal, QC
| reply to BobTheVeg Here is 2 pictures of the custom build RS-232c cable
I took an old "D-sub" of the remaining parts of an old computer. »en.wikipedia.org/wiki/Image:Dsubs.png
And an old COM1 mouse. I had to cut into the connector in order to see which color is which pin number.
I also pulled out the IDE pins of an old ISA sound card (CD-rom was connected on the sound card at that time). I used the pins to connect each wire together. |
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 BobTheVeg
join:2004-09-05 Montreal, QC
| reply to Bicephale
 24h with config |
Here is the result after 24 hours with the settings you suggested me.
I just noticed that we have a different software version. I assume upgrading this is the danger of flashing you warned me about. |
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  Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Hi,
I looked at your 1st tweak attempt and marked the elements which you may want to modify, my suggestion is to proceed in three steps. 1st, emulate previous tweak samples and yet try to use realistic values when necessary (clearly, "DownStream" and "Tx Power Atten.", considering that an SNR Margin of 6 dB doesn't leave room for "Tx Power Atten." adjustments). I'm not sure the "DownStream" field can really affect the final results but i'd give the ISP a phone call and ask what the RCO numbers are in order to have a clue what number to enter there...
Step 2 represents the major part of the work to be done, you're on your own on this one as it is not an exact "science"!... I recall that it was necessary for me to acquire some "feeling" relatively to how the US/DS tweaks worked, the numbers i gave you are only for starters, it was in hope to provide a setup that connects.
Step 3 is optional, once you got acquainted with it much better it's permissible to explore a tighter form of control, namely the bin weight.
I'm sorry that's all i can do, the DSL Reports site doesn't work well for me tonight... I think i'll be lucky if i can post at all! |
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  Bicephale
join:2005-09-24
·TekSavvy Solutions..
| reply to BobTheVeg Hi again,
I revisited your inital post, i woke up and thought maybe i could get thru once more...

When i align the numbers on a paper sheet, these conclusions emerge: the attenuation levels are both steady and so is the Remote/ UpStream SNR Margin which is a mere 6 dB. I can observe both power levels fluctuate: on the Local/UpStream side from 10.12 to 12.48 dBm, on the Remote/DownStream side from 7.63 to 8.63 dBm. Finally, the Local/DownStream SNR Margin varies from 15.5 to 18 dB but we see this happen quite often on DSL Reports.
Now, the "noise" curve says that your line is suitably quiet except on some occasions. The level of CRC Errors you're experiencing is of no concern and it is normal to have so few on an interleaved profile such as yours.
Well, there can be noise bursts but at the moment this is what the curve leads to...

The UpStream SNR Margin, on the other hand, is a major problem since there's no safety margin left. I was hoping "Spectral Shaping" would help here by allowing you to lower the UpStream speed to something like 512, 384, 288 or even 256 Kbps - whatever it takes...
Unfortunately, the late 'DMT' capture appears to indicate that your GNet BB0060B device is not responding to tweaking the way mine does; it's so puzzling i wonder if you saved this configuration and rebooted (a cold power-up boot, for example)... In any case, the final objective is to make trade-offs relatively to your UpStream signal as i just explained.
Lets suppose you managed to force this GNet unit and its peer to negociate 2496/288 Kbps, that doesn't mean you won't be able to find a "sweet spot" where the UpStream SNR Margin will be adequate/tolerable. Using "InterLeaved" mode already, tweaking might buy you a raise of profile but there's something wrong with your attenuation levels: they tell me your estimated "GNet distance" is shorter than my own by five hundred meters and yet i'm on a 6016/512 Kbps Interleaving profile! So, it seems to me it's likely because of a wiring problem which Bell "fixed" by lowering your profile instead of actually going after the source of failure... I've thought of urban cross-talk as the explanation but it would not resurface like this just because one more DSL neighbour arrived or switched to "Total"!

There are limits to what MoDem tweaking can accomplish and trade-offs have to be made, it's not going to resolve any phone line issues magically but good trouble-shooting can help you to understand the situation and then you will be more persuasive when the time comes. |
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 BobTheVeg
join:2004-09-05 Montreal, QC
|  Reduced speed |
I used the settings you gave me. Reduced the upstream bins/speed. I enabled the log each 10min and noticed that the Downstream SNRM has hit 20.0 over the day which I never seen before. As opposed to 11.5 from my first screen shot. |
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  Bicephale
join:2005-09-24
·TekSavvy Solutions..
1 edit | Hi,
There's still a problem with the UpStream SNR Margin so it would be hard to convince your ISP to ask Bell for a profile raise, in my own opinion! If the decision were mine, i know i'd have a hard time trying to put in the balance the fact that you're on "Interleaved" mode vs your relatively stronger DownStream signal.

The areas coloured in purple are those you must focus for the time being, while the ones in red shall guide you toward the goal to attain... 1st of all, call the ISP and request that they capture the statistics from Bell's "Line Test" portal in order to know what your RCO numbers are with and without tweaks, additionally to the attenuation levels. The other numbers coming from the ISP's end would be nice to see as well. As for the tweaking itself, once you have done this you will find that there's no easy way to accomplish this: it's a slow process during which you must try to learn what value ranges are acceptable. Ideally, this must be done one parameter at a time and then you can try combinations later... For example, it's probable the MoDem won't connect if you change all the numbers at once using extreme values; lower 1 parameter slightly (in steps) each time until you reach a limit beyond which issues occur. Keep in mind that this limit may very well move while other parameters are optimized, meaning you better revisit previous limits when some progress is made and then back off a bit to remain in the stable operating range. The objective is to give away some transmission power and hence related noise: watch the UpStream "Tx Pwr" (Transmition Power) level in hope that a few less dBm will translate as a few more dB, with the UpStream SNR Margin but possibly also the DownStream SNR Margin since less local noise should leave more room for the DownStream signal too.

Euh... I made an error about the RCO in this graphic: you should read "Enter Maximum Theoretical Speed based on RCO"!... It may equally tell us what's a viable target.
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  Bicephale
join:2005-09-24 | reply to BobTheVeg Oups!
I forgot to mention the Maximum Theoretical Speed is supposed to be a multiple of 32... |
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  Bicephale
join:2005-09-24
·TekSavvy Solutions..
1 edit | reply to BobTheVeg Hummm...
More comments!
Your present operating rangess are:
DownStream/Remote Power = 7.63 to 8.63 dBm UpStream/Local Power = 10.12 to 12.48 dBm UpStream/Local SNR Margin = 15.5 to 18.5 dB
-=*=-
2008-Jun-1:
Perhaps "UpStream/Local SNR Margin" should read "DownStream/Local SNR Margin", it's a bit confusing if one compares the Web GUI and 'DMT' outputs!...
-=*=-
As you can see, the SNR Margin gain, even if it is improved relatively to the very 1st post, now doesn't make much progress since 0.5 dB can't be considered to be signidicant due to fluctuations.
I'll know you've started to implement a form of Spectral Shaping once the numbers moved below the Power ranges shown above. By the way, more Power means more heat so i suggest you find a way to keep your GNet relatively cold if the work- load makes it necessary... Now, in reality it's not what i would call an overwhelming task to tweak a GNet: it can be slow but right now i see only three fields which need to find their "sweet spot"...

The "max. Bits/Bin" box might make the DSL signal paradoxically stronger when its values decreases but even if it's made a bit more immune to noise you may actually observe a lower SNR Margin past the sweet spot. If you don't wish to evaluate the whole sequence from 6 to 13 then i'd suggest you try to proceed by halves. Determine what's the limit, find the value halway and test this one. If it works better, use that value as one of the new limits and proceed in the same manner by finding another half-value again. It's not garanteed to work in a predictable way but you can try to save some time and effort in that manner. Once your trade-off via the "max. Bits/Bin" field is done, you can work on the "Upstream frequency bands".
This one is trickier but a thinner/lower range should translate as less local interference...
Lets say the upper limit is set to 32, that's as close to your DownStream bandwidth as you should get and you just want to do the opposite. Go way down until it breaks and back off a bit to get a working signal again. The bets are open, it may be something like "8 - 14", "12 - 18", 6 - 14" or whatever. Watch the transmission power level and when you're satified that it's been decreased a bit try a new "Bin Weight" ("max. Bits/Bin"), etc. |
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 BobTheVeg
join:2004-09-05 Montreal, QC
|  New DSL OvisLink OV303R2 |
After reading alot about BB0060, aei.ca proposed me to try ( as long as I pay first and refund if it fail ) a new DSL.
The values are promising, I hope I'll reach a good profile with this. |
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  Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Hi,
I insisted a few times that you should get the RCO numbers and then proceed further but i can see that those OvisLink OV303R2 statistics suggest you can be put on a 5056/640 Kbps Interleaved profile right away! I'd still like to know how both devices will compare once you're upgraded, 'DMT v8.07' supports the BroadCom based MoDems so let us know if this 'DMT' build works for you, in any case! Good luck, i noticed your UpStream SNR Margin is still 6 dB...
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