DesiGuy1981
join:2008-05-01
Scarborough, ON
| reply to TilhasBB
Re: SpeedTouch 516 Tweaking :)
just want to let u know with DMT..i was able to boost the speed by more than 50%..if u see my first snapshot..i was only getting 600 kbps downstream...but nop i get about 1344...which is preety good...the only thing im trying to do is if i can lower the upstream...that mite boost the downstream may be a littel bit...that wud be a good achievement. |
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Bicephale
join:2005-09-24
 ·TekSavvy Solutions..
·Velcom
| Hi,
I'd like to see how 3Com USR-9108 tweaking would perform
in this case (it's supported by 'DMT v8.x', according to
ggpr) but you have a "locked" SS5200 instead. Well, the
Bell MoDems will operate as "dumb" units by default if i
am not mistaking. Install it in front of a router of use
the Windows MiniWAN adapter to manage your PPPoE session
externally and the MoDem should work in "bridge" mode...
If that works (i'm no SpeedStream owner myself) you must
find out what HardWare version you've got before anything
else. Once that is done the magic word will be "unlock"
but those discussions are most probably required to occur
in the background (privately). As for Spectral Shaping,
the only thing that might be close enough is a ferrite
choke installed on the MoDem's phone/WAN input. With a
DownStream band this tiny my bet is that you have to use
a fairly large toroid to be able to wrap as much as tenty
some turns of RJ-45 phone cable around it. You won't be
able to affect the UpStream band but this may eliminate
a few weak DownStream bins near A.M. interfering signals.
Euh...
Cross you fingers that an SS5200 with some RF choking does
improve your RCO figures! In absence of real Spectral
Shaping festures that's all i can think of right now.
 |
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Bicephale
join:2005-09-24 | reply to DesiGuy1981
N.B.:
By "fairly large" toroid i mean 2+ inches. |
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dslgr
join:2008-05-07
| reply to DesiGuy1981
@DesiGuy1981 try clicking the "Option 2" checkbox under the noise margin bar and then hit the "apply / resynch" button.
It supposedly activates the power cutback on the ST, decreasing internal crosstalk and lowering the upstream rate in favor of the downstream. I say supposedly because even the creator of DMT Tool, doesn't really know if it works or not. Some users said it did work, some said it did nothing. Probably it has to do with the fw, the DSLAM, etc.
The latest fw that works 100% with DMT Tool is the 6.1.0.5.
What's the situation with the modemoption 2 tab? Is there an option to increase the Register 0D, Register 0E bars? They supposedly (once again no guaranteed results) increase the Remote TX Power, which in your case probably has some room for improvement.
Register 0E is for use with firmwares under 6.1.0.5 and Register 0D is for the 6.1.0.5. You could try, at your own risk of course (imo there's no risk at all, but I have to state it nevertheless), to fiddle with those bars. When you move them, return to the modemoption tab and hit the "apply /resynch" button in order for the change to take effect. |
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Angelo_
The Network Guy
Premium
join:2002-06-18 | on the 3com no tweaks
ADSL Information
Internet Downstream Internet Upstream
SNR Margin (dB): 10.9 17.0
Attenuation (dB): 61.0 31.5
Output Power (dBm): 11.9 18.1
Line Speed (Kbps): 3840 964
Rate (Kbps): 3008 512
|
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DesiGuy1981
join:2008-05-01
Scarborough, ON
edit:
May 7th, @08:05PM
| reply to dslgr
hi dslgr..thanx for ur reply
heres some snapshots...
i have changed th firmware to v6.1.0.5
Bicephale..ill try to hook up speedstream 5200 over the weekend..thats when ill have mroe time to play around with it..thanx again all for ur time.. |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
·Velcom
| reply to dslgr
Hi dslgr,
Thank you very much for offering some feedback about your
3Com USR-9107: Spectral Shaping made on a per-tone basis
and via a GUI as above certainly stimulates my curiosity!!!
The US Robotics SureConnect 9105 CLI Command List refers
to some "--tones" parameters but i'll confess that i find
the GUI a lot more intuitive; DesiGuy1981 would be able
to explore real options should this be available to him,
no doubt. I've been hoping to meet with a pioneer who's
willing to test the 3Com's Spectral Shaping abilities for
quite a while so here's how that's supposed to work. In
short, the idea is to use as few UpStream bins as possible
so that the output level will generate less local noise;
it would seem even better if you could adjust the bin's
weight on an idividual basis as well but it will have to
do... My post titled "GNet Tweaking" illustrates how one
can control the DownStream/UpStream speeds on his GNet:
GNet Tweaking, Bicephale, 2008-Feb-18
You may not have a "Bits-per-Bin" option but weak tones
can be disabled individually, on the other hand. Tweaks
like this don't "boost" the speeds without taking their
toll: be prepared to settle for a trade-off where you
let go some performance on one hand to gain on another.
Usually, equal RCO numbers confirm that a fair bablance
has been reached; i shown some examples in this thread:
Tweaks, Bicephale, 2007-Aug-27
One other indicator to keep an eye on is the CRC Error
rate: you're making real progress if it's brought down
consistently - and i mean the numbers need to be sampled
over days instead of minutes... My own case, which you
mentioned so nicely, demonstrated how trouble-shooting
can help and what an appropriate fix may look like. At
the moment, my RCOs are near 85 % (DS)/87 % (US) and an
SS4200 can make it even lower at 59 % (DS)/73 % (US)!!!
In conclusion, there's hope but the DSL customers are
on their own; they need to develop patience and to earn
new skills - which begins with concepts grasping and i
think "Internal Cross-Talk" is one that falls well into
this category. I just gave up relatively to the Thomson
SpeedTouch, though. My impression was that 'DMT' worked
better with the v5 line but i abandoned all hopes one
dozen FirmWares later so i'd rather not comment further
on its theoretical tweaking abilities... To be honest,
the tweaker's dream machine must be lying elsewhere!...
I find that the site's old timers overlooked the tweak
topics for too long, my attempts to raise interest over
this have failed miserably but there's a product similar
to the 3Com which supports bin-per-bin Spectral Shaping:
it's from D-Link and the exact model number is DSL2320B!
Various DSL modems, Bicephale, 2007-Sep-18
This GUI sure feels a bit familiar to yours, doesn't it?...
Once again, thank you! |
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Bicephale
join:2005-09-24 | reply to DesiGuy1981
Good luck with your week-end tweaks!
 |
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dslgr
join:2008-05-07
| reply to DesiGuy1981
@DesiGuy1981 apparently, there was no positive outcome from the changes you've made with DMT. Unfortunately, it is a tough situation, taking into account the very high attenuation your line has, but I understand your efforts to get the max out of it.
The only thing I can think of, is to ask from your ISP if they can increase the Remote Tx Power, from their side. Doing so will give you another boost for sure, considering that there should be at least another 4dbm room for increase (in order to reach 19dbm in total). |
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dslgr
join:2008-05-07
| reply to Bicephale
@Bicephale first of all, I would like to thank you for the comprehensive post you've made above.
I can see your excitement for the USR's tweaking capabilities, as it matches mine, the first time I realized I could "play" with my line and try to get it to reach its limits.
Sadly though, my initial expectations weren't met and that's why I asked you in my previous post if there was something more besides tone selection, that could have slipped my mind.
I agree that tone selection is a nice feature but imo it can't compare with the tweaking options the GNet, for example, has to offer, which you are very familiar with, as you made the best out of them.
From what I gained from my experience, there's not much tweaking you can do and benefit from it. It's straight forward really, you just select which tones to use and I have "played" both with the cli --tones parameters and with the GUI too. Eventually I realized that besides the extra parameters, it gives you the exact same results.
Reading that the cli command lets you specify the starting tone used in the upstream and downstream direction, and the number of tones in each, my mind went at once to spectral shaping. And with spectral shaping I mean something like that. Unfortunately there's no such option, or at least I couldn't make it work. Regardless of the bitmap I sent to the router, it just masked some tones and didn't change the spectrum.
The only use I could find for the tone selection feature is if you have some kind of RFI which you can't avoid and which hits at random time and in specific frequencies. With tone selection you could exclude those problematic tones, so you won't have to worry if the RFI is on or not, leaving your line steady in all cases.
In your post, you mention another benefit from it, which I hadn't really considered and that's the reduction of internal crosstalk. I probably didn't think of it because I value the upstream rate too much (and it already has a hit, as an annex b line, and from my crappy NT1 device), to sacrifice it for a bit more downstream, but I would be more than glad to give it a try first chance and present you with some results.
In fact, if you like, you could give me specific parameters you would like me to test (like specific tones, ranges and such). The only problem is that I can't really give you longterm statistics (such as crc errors in days uptime) because unfortunately my line is not so stable. With the ST I will probably have a drop every one or two days, which doesn't really bother me, but with the USR, that number goes up to 4-5 a day, so you see I can't collect enough data.
Those are my thoughts for now. I will be waiting for a response while getting the USR out of the drawer. Hope there's more to do with it.
Greetings from Greece and a fellow tweaker.
Thank you. |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
·Velcom
| Hi,
Perhaps there's next to nothing to tweak on your side
simply because nothing is really broken as some of us
around here would consider 24 Mbps with pure envy!...
DesiGuy1981 would be lucky if could get 2496 Kbps; if
he were the one with a 3Com, i'd recommend him that he
tries an UpStream band starting with bin 6, 7 or 8 and
ending with bin 14. This should limit the UpStream
signal to 256 Kbps or so and then, maybe, he would be
allowed to dream of a DownStream speed of 2496 Kbps...
I expect the DownStream starting bin to be somewhere
between 32 and 36 and i find it even more improper to
guess what the ending bin should be but lets put it
in the 70 to 248 range. Most unfortunately, your own
DSL signal doesn't compare with that of DesiGuy1981 so
i'd rather not draw definitive conclusions from future
tests: i've learned to be carefull with predictions, not to
mention i found no gain/bit-loading CLI commands neither.
I suppose a Bell technician wouldn't raise his profile
unless there's a strong basis to request it anyway.
Fingers crossed...
 |
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dslgr
join:2008-05-07
edit:
May 8th, @09:54PM
| Well my line has its problems too. After all, that's what got me into this tweaking expendition I started some time ago. If everything worked as it should, then I probably wouldn't look any further.
First of all my line is up to 24Mbps/1Mbps, which for me that I live about 2,5-3km away from the CO, means that I get to enjoy about half of that. My line is ADSL2+ over ISDN (annex b), rate adaptive with a target SNRM of 9db for the downstream.
It usually synchronizes around 10-11Mbps DS and 650-700kbps US. I should have been able to have 1Mbps upstream but that's where my second problem arises. The upstream takes a big hit, mostly from my NT1 device (the device where the phones connect in a ISDN line). That's why I was looking for a spectral shaping solution, but unfortunately haven't been able to find one till now.
Wish I could do some tests for DesiGuy1981, but as you have already said, our lines are disproportionate. |
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DesiGuy1981
join:2008-05-01
Scarborough, ON
edit:
May 9th, @06:08PM
| reply to dslgr
thans dslgr..ill call my ISP and ask em to increase TX power..im not too sure if they wud do anything...when i complained about the speed..they said theres nothing they can do..but if i want i can cancel the account with no charge...apparently i signed a contract with emf or a year..
thanx aagin..and yes i wish too that u can do some test for my line..lol
UPDATE: The primus tech support does not even know about Remote tx power. so they cudnt help. |
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DesiGuy1981
join:2008-05-01
Scarborough, ON
| reply to Bicephale
than bicelphale..i wonder whats a 3com? is it a software like DMT? if it is how can i download it?
r u suggesting me to download U.S.ROBOTICS software? i can give it a try...
i luv readin wat u guys write but the only problem is u guys use so professional wrds that so go over my head..lol
im very new on this..so plz bare with me. thanx again both of u..i do appreciate ur help. |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
·Velcom
edit:
May 9th, @10:07PM
| Hi DesiGuy1981,
I don't know about dslgr but i was as professional
as any other user when i subscribed to DSL for the
1st time so i'd like to help you save the time and
frustration if i can. You don't have to embrace a
learning curve as steep as mine was, just consider
that the existing 3rd-party trouble-shooting tools
will help you to acquire a proper understanding of
the situation. 'DMT' is the most popular, use the
version corresponding to your MoDem, if supported.
My favourite trouble-shooting tool is the 24 h CRC
Error ("noise") curves generated by a GNet BB0060B
using 'DMT v2.20'; those from an Efficient SS4200
with generic FirmWare combined to 'DMT v9.01' seem
even better but i haven't tried that one just yet.
Typical SNR Margins are approximative as they vary
throughout the day, sometimes they're even totally
paradoxal. See for yourself by reading this post:
SpeedTouch 516 Tweaking :), Bicephale, 2007-Dec-11
According to the record shown above, it's possible
to register normal SNR Margins during a disruption
and then to read mediocre values once the noise is
gone! Of course, some people here will argue that
my GNet was faulty but my reply to them is that it
must be a self-healing GNet then! The same people
will brag around about the SpeedTouch which didn't
provide any "noise" curve at all until i asked the
author of 'STMT' to include this function; try it
if you have no alternative but be warned that i've
catched my ST resetting its counters unexpectedly.
Anyway, i suggest you keep in mind that trade-offs
are required while tweaking and that you shouldn't
rely on SNR Margins (static numbers) only: try to
gather stable feedback from a mix of RCO figures &
long term CRC Error rate curves as you toy around.
Now, here's what i mean by 3Com: "3Com USR-910x".
That's a MoDem brand/model and the D-Link DSL2320B
has an equivalent Spectral Shaping capability. My
underlying thought, i must confess, is that i'd be
more optimistic if you could use other HardWare!!!
Only three units are known to do Spectral Shaping,
only one of them got its tweaking abilities tested
(GNet's BB0060B) and this item was discontinued so
you probably won't find one of those in your local
electronics store. As i wrote before, practically
no interest could ever be raised relatively to the
Spectral Shaping topic and all we got to gather an
overall picture of this feature is my own numbers.
In other words, you may end being your own guru...
Congratulations, the average unsatisfied DSL users
would rather switch to cable than enter this quest
alone! Phone companies like to lower profiles, it
isn't profitable to send skilled technicians every
time a customer complains and 3rd-party ISPs don't
give orders to them: at best they open "tickets".
Normally, only you can pinpoint wiring problems or
evaluate devices in search for the ideal candidate
and there's no garantee you'll succeed in the end.
Phone companies like Bell would go bankrupt should
they compete with cable via pre-emptive techniques
such as systematic twisted-pair wiring, shielding,
RFI control by using ferrite toroids if necessary,
and, why not, on-site DSL unit tweaking (if it can
support it - which it doesn't, usually)! I may be
mistaking but it looks like Bell and others chosen
distributed filtering over existing phone cabling,
in hope that the subscribers would be satisfied to
finance the next fight (with help from ADSL2+ when
the time has come). I bet our forum didn't become
so popular because the phone guys guessed right...
Their plan left a few customers behind, welcome to
your new DSL neighbourhood! After a while it will
feel like amateur radio: the hobby makes us busy.
Well, i don't want to end my message on a negative
note so i added captures to boost your motivation:
Now, imagine if we knew the answer to this riddle:
|
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Bicephale
join:2005-09-24 | reply to DesiGuy1981
Remote Transmit Power is 20 dB or so when the line is
fine, it's negociated to a lower value because there's
a bottleneck located somewhere on the line, i believe. |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
·Velcom
edit:
May 9th, @10:08PM
| reply to dslgr
I don't want to minimize your problems, i just think
that the ADSL2+ protocol probably serves you right
under these circumstances. You mentioned being on
ADSL2+ Annex B, here's the illustration i could get:
You may have to use relatively expensive filtering
circuits to reject the ISDN band as it is closer to
the DSL band. Perhaps you should ask your provider
to do the tweaking for you: for example, request a
change to 9984 Kbps/512 Kbps if they don't mind...
Euh... But i read that you want to win on all bets
so that won't work for you i'm afraid! So, if no
trade-off is possible on the software side then you
are left with your phone wiring. Anything you can
improve? Still in the HardWare department, i have
this riddle for you. The answer might point at a
solution which many of us might also benefit from:
|
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dslgr
join:2008-05-07
edit:
May 11th, @12:11PM
| reply to Bicephale
If DesiGuy1981's modem readings are correct (which we can't take for granted), then my guess is that the Remote Tx Power is lower than it should, due to misconfigured power profile at the CO DSLAM (you also use the word exchange for it if I'm not mistaken?) or bad ISP network topology.
There's a reason PSD (Power Spectrum Density) masks are being applied and that is mainly to reduce crosstalk among lines in the same bundle.
If all things worked as they should then, by ADSL-standard definition, the Maximum Nominal Aggregate Transmit Power for the Downstream is, as you correctly said, 20dbm and for the Upstream 13dbm.
That means that in a properly configured providers network, for DesiGuy1981's case, there should be room for a signal power increase, leading to an increased downstream rate. But unfortunately, as it seems, since the call has already been made, that's not the case here. |
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dslgr
join:2008-05-07
| reply to Bicephale
The illustration you presented is correct, with the addition that the downstream goes up to 2200kHz. Tone 32 (138kHz) to 64 (276kHz) for upstream and 64 to 512 (2200kHz) for downstream.
You are also correct about the fact that a trade-off (especially in the upstream rate) is not preferable and that one solution is expensive filtering circuits.
I've searched the internet extensively for a high quality filter that could cut the "noise" that my NT1 is injecting into my line in frequencies that it shouldn't, but unfortunately, although I tried a couple of splitters, I couldn't get one that does the job. My next move will be to try to construct one myself, when I find the time.
Changing that crappy device for a newer model would possibly make things better too, but that's not an option atm, so for now I've decided to live with it.
For your question now, because I am fairly new with the forum and I haven't been used to following lots of threads easily, could you provide me with some details regarding the graph?
From what I get, you are looking for a router's chipset that could provide a DS rate of around 2Mbps, for a 78db attenuated line? Where does that graph data come from? |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
·Velcom
| Ho DSLGr,
We're seeing more and more degradation cases where the
customer complains that his UpStream speed is lower than
it used to be. In my opinion, Cross-Talk would explain
this situation easily if we could accept that DSL has
gained popularity through time - which means Cross-Talk
levels must have increased a great deal during the last few
years. In my region, the phone company is using strudy
flat copper pairs to bring our DSL signal from the pole
to the house, that's where some progress can be made: i
showned it by turning a noisy & slightly unstable 4032/800
Kbps FastPath access into a quiet & stable 6016/512 Kbps
InterLeaved one using shielding and some RFI control...
The previous ADSL graph is for the 1st generation DSL
service, i believe ADSL2+ would have twice as many bins,
e.g. 512 bins instead of 256. By the way, did you try
to force your MoDem to negociate ADSL v1 only? That's
not going to solve your problem definitively but the
additional stability that it might bring would be one
more clue to guide you in the right direction... Sorry,
i don't see how to help you other than to mention that
TerTech is using a SpeedTouch with FirmWare v6.1.0.5.0
('ZZQOAA6.105') in combination with 'DMT' MoDemOptions.
The same person also shown me where his DSL device is
located on the graph by John Bullas (from Flickr site)
and i'm afraid that your speed might be even worst if
you were living around here, according to the curves;
DesiGuy1981, on the other hand, can expect up to 2M5
bps unless TerTech's unit is marginal. I wish i knew
what MoDem John Bullas tested to read 1M7 bps @ 78 dB
but i don't suppose he kept a record of that...
Have a nice day! |
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