dslrocker3
join:2002-05-26
Toronto
4 edits | Help/Advice with my Line Statistics please Hello. I have always had a problematic line but a few years ago, I was able to get them to cut some wiring dead-ahead to get a stable 1728/640 (interleaved) using my trusty old Speedtouch Home. A few months ago, I asked my ISP, Velcom, to ask Bell to examine my line statistics again because I had a different modem hooked up that was capable of RE-ADSL (reach extended) in the form of a Speadtream 5200 E242. They were able to changed by profile to 2496/800 fast path, with no to very few errors and the RX SNR usually ranged between 10 to 14 decibels.
A few days ago, the phone line "gremlins" have resurfaced. Interestling enough, I have always received better line statistics inside the house than when I hook my modem directly to the jack at the demarcation point (bridge tap at work here? extra 100 or 200 meters inside my house adding more distance making a better connection?). Before Bell changed the profile yesterday to 2496/640 interleaved, I went to the demarc and got about 1850/800 with SS5200 and about 1000/800 with ST516 (this modem really didn't like something at the demarc!)
- but a little higher with the SS5200 and a lot higher with the ST516 if connected inside the house.
You will notice that I have tried 2 different modems to rule that out as the problem. I have tried a different phone wire and have tried different jacks within my house. I have even hooked up to the demarcation point (with even worse results).
In the picture are the line stats from my ST516v6 and in the text below are statistics from my SS5200 E242. SS5200 E242 is a lot more aggressive in connecting at higher speeds but results in more errors. ST516 refuses to connect at higher speeds for the "bad" portions of the signal but that results in much more stability (is more fussy and won't connect at rx snr below 7.0). I have a Bell techncian coming today to look at the line.
Advice/thoughts/insight? Thanks.
ss5200 e242:
DSL Status
Status ATU-C Current Tx Rate
(bits/sec) ATU-R Current Tx Rate
(bits/sec)
UP 1984000 640000
DSL Statistics (accumulated at 15 minute intervals)
System
Time Tx
CRC Tx
FEC Rx
CRC Rx
FEC LOS SEF LOS
(sec) SEF
(sec) Err
(sec) Rx
(blocks) Tx
(blocks) SNR Atten.
02:35:36 0 0 0 173 0 0 0 0 40 18185 18185 5.0 56.5
02:30:28 0 0 0 694 0 0 0 0 115 53078 53078 5.0 56.5
02:15:29 0 68 0 927 0 0 0 0 134 53174 53174 6.0 56.5
02:00:28 0 0 0 818 0 0 0 0 141 53182 53182 5.0 56.5
01:45:27 0 0 0 559 0 0 0 0 80 53183 53183 6.0 56.5
01:30:26 0 0 0 308 0 0 0 0 98 53182 53182 6.0 56.5
01:15:25 0 0 0 331 0 0 0 0 94 53131 53131 6.0 56.5
01:00:25 0 0 0 431 0 0 0 0 94 53175 53174 6.0 56.5
00:45:24 0 0 0 539 0 0 0 0 79 53180 53181 6.0 56.5
00:30:24 0 0 0 127 0 0 0 0 45 53181 53181 6.0 56.5
00:15:23 0 0 0 1279 0 0 0 0 51 53082 53081 5.0 56.5
Totals 0 68 0 6186 0 0 0 0 971 549733 549732 N/A N/A
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noisey
@videotron.ca
| Re: Help/Advice with my Line Statistics please Noise problem.
These things tend to happen in spring and fall on the lines outside.
On a stable line you should be able to get 3-meg interleave, or at worse the 2.5-meg interleave with 640 upload.
Only advice I can give is to tell the tech to make that SNR go up.
Have you noticed if you occupancy has gone up at all since the problem surfaced?
If so, tell him that. its a sign of a wire problem outside (maybe wet wires, maybe a voltage cross etc.) | |
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just noticed
@videotron.ca
| Re: Help/Advice with my Line Statistics please I didn't read the whole post you made, sorry.
yeah I would say there is something wrong with the wiring at the demarc or something wrong with the way its set-up.
doesn't make sense that you get 2.5 in the house and 1 at the demarc.
Some type of short for sure.
Let the tech know. | |
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dslrocker3
join:2002-05-26
Toronto
4 edits | Let's just say that a few years ago, I was told by a field technician that the line was trouble waiting to happen. I think the technician said something about voltage on the line but that they were not able to fix it/not cost feasible. Supposedly, the pair with the strange voltage readings is the one that is able to provide the higher speed connection but I was essentially warned that it could be problematic in the future. The other pair on the pole behind my house was very clean but couldn't even provide a 1Mbps connection.
When things are working properly, the results at the demarc and at a jack inside the house are usually about the same. But when I check yesterday, espseically with the ST516, that's when I noticed an extreme difference (ie. worse connection at demarc). How is this possible? | |
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Bicephale
join:2005-09-24
 ·TekSavvy Solutions..
2 edits | Re: Help/Advice with my Line Statistics please If you've been told that you could "bypass" your house wiring
by connecting directly at the demarcation point then now you
learned the truth about it: it's fundamentally wrong because it
doesn't account for the "antenna effect" of your wiring hidden
behind walls - which can amount to a couple hundred feet in a
private home!... Centralized filtering eliminates confusion, long-
term noise curves reveal daily patterns if any and hence point
at potential local issues. Thomson's SpeedTouch 5x6 combined
to TerTech's 'DSL_StatScope' professional-grade utility is quite
the most user-friendly way available to acquire a better overall
perspective of the situation... Beware of SNR Margins as these
can remain stable for days if not weeks and never give a single
clue about what's really taking place. 'DMT' captures are great
for a quick start, "Diagnosis" mode is powerful when it becomes
more serious but 'DSL_StatScope' is much less involving, IMHO.
This is TerTech's 'DSL-StatScope' thread, for your convenience:
%20.GIF)
Yet Another Modem Statistics tool, Bicephale, 2009-Apr-10
Addendum:
Oh, and 'DSL_StatScope' can record logs which other
readers can "PlayBack" and examine as they see fit.
Also, this short thread illustrates the next step:
The customer's own wiring, Bicephale, 2007-Jun-13
Red is bad, green is good... | |
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| | dslrocker3
join:2002-05-26
Toronto
4 edits | Re: Help/Advice with my Line Statistics please It's interesting how you talk about an antenna effect. When I troubleshooting years ago, I decided to change some of the wiring in the house. I removed some wiring that was causing a problem (maybe a staple in through the wire?) and ran a new line up to my modem.
I wasn't willing to drill through the floors and walls so what I did was bridge from a downstairs jack with cat5e to where I wanted to place my modem on the second floor. The downstairs jack where my connection is bridged acts very strangely. To get the best connection and to get the second floor jack up to par with the other jacks throughout the house, I have to plug in an extension cord into the first floor bridged into jack (and it has to be a certain, specific cord for some reason) and it must be left unfiltered with no device hooked up to it. This adds about 0.5 dB attentuation but gives a better connection. So I guess this all means that less attentuation/least amount of wiring is not always better, depending on many factors. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Re: Help/Advice with my Line Statistics please When i moved in, my MoDem couldn't be located conveniently
so an HPNA EtherNet extender is the solution i chose to avoid
wiring issues which i just didn't want to address back then. It
would be profitable to remove everything but the DSL device,
electrically speaking - which means using Centralized Filtering
is a must if you haven't tried it yet! Long phone cabling can't
but cause trouble, if it helps that's because something is dead
wrong, as i illustrated in one of the linked threads from above.
In the end, what you should go after is lower noise and hence
fewer disconnections. It doesn't matter what the SNR Margin
is as long as you remain connected... My SpeedStream works
reliably below 6 dB, my SpeedTouch doesn't. Many parameters
may appear to be relative in the DSL world, that's why i prefer
to compare curves these days: i've found better. | |
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| dslrocker3
join:2002-05-26
Toronto
1 edit | LOL, I guess that I really shouldn't leave the SNR target set to 1dB since there is an open trouble ticket. I was surprised that on a speed test, I was still able to get 2000/500 Kbps even with all those errors.
On a side note, I've noticed that this ST516 is much better at error correction than the SS5200 E242. The E242 seems fine with interleaved turned on but it's horrible on a high error line if you are on fast path, at least from my observations. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Re: Help/Advice with my Line Statistics please Have you considered disconnecting everything at the
demarcation point to test your MoDem from there? It
is a tweak you're showing here, right? Hoping for some
happy ending, i guess...
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| | | dslrocker3
join:2002-05-26
Toronto
4 edits | Re: Help/Advice with my Line Statistics please I haven't done that since the profile change that turned interleave on.
When the profile was set to 2496/800 fast path, I was getting about 1850/800 with the SS5200 E242 and about 1000/800 with the ST516v6 at the demarcation box's jack (about 2000/800 and 1700/800 inside the house).
Yes, that last picture was with the tweaked settings. | |
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| | | | | dslrocker3
join:2002-05-26
Toronto
3 edits | Re: Help/Advice with my Line Statistics please I turned down the slider for the target noise margin forcing to modem to pretty much accept any and all signals, regardless of how bad they were.
I haven't tried there yet. With evertyhing disconnected, the only difference from the inside the basement and the grey box would be about 6 feet of thick wire. Could the results actually be theat much better at the bolts in my basement when it is fed by the same jack that I already tested at in the grey box? Long ago, when I was trying to get a stable 1728/640 with a non RE-ADSL modem, I used a phone jack and hooked it up in the basement by using an old ethernet cable that was no longer being used because the clips on the end were broken. I'll have to comptemplate perhaps doing that again - or perhaps "sacrificing" a phone cord by chopping one of the ends of it.
My next step might be to go back to the outside grey box demarcation point and feed an cable like I did before directly to the bolts there, except on Bell side of the demarc making directy contact with the drop wire - although I strongly suspect that Bell really doesn't like it when you do stuff like this. | |
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ex bell
@cgocable.net
| Re: Help/Advice with my Line Statistics please said by dslrocker3  :My next step might be to go back to the outside grey box demarcation point and feed an cable like I did before directly to the bolts there, except on Bell side of the demarc making directy contact with the drop wire - although I strongly suspect that Bell really doesn't like it when you do stuff like this. They aren't lurking out there now are they? 
Sneak out quick and wire a jack right to the drop wire.
You can wire on to the drop or bsw for a bit unless there is a storm in the area.
Bell doesn't care as long as you put it back together before you have them come there for a repair.
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dslrocker3
join:2002-05-26
Toronto
3 edits | Bell didn't even bothered to show up to day for the scheduled appointment today. I know they showed up yesterday unannounced but told a person at my place that because I (the person who uses the internet here) wasn't home, he would just come back tomorrow (which was today, Saturday, during the originally scheduled time). They closed the ticket and said that conclusively declared that I have a defective modem (even though I have 3 of them sitting beside me) without checking anything at the demarcation box or by climbing the utility pole behind my house. I wouldn't be surprised if the technician's log claims that he came at the proper scheduled time, when in fact he didn't.
Oh well, another trouble ticket has been opened. I'm skeptical now what will happen and I have a bad feeling that I will simply be changed to 1728/640 interleaved even though I was stable for 3 months at 2496/800 fastpath with a RCO that wasn't maxed out (SNR varied from day to day from about 10 to 14 dB). | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Re: Help/Advice with my Line Statistics please Hi,
Sorry to hear that!!! Perhaps your DSL device isn't holding
at 10+ dB 100 % of the time and that's how Bell came to
close your ticket, i sort of wonder. This is the problem i'm
having with single snapshots: generally speaking, we can't
be sure.
Look closely at the 3rd (grey) spectral envelope graphic:
...now look at yours:
Based on this i honestly believe that it's reasonable to ask
for an opportunity to try 3008/640 Kbps Interleaved for a
while - if that profile happens to exist, of course. You can
use 'DMT' to force the unit to reconnect but maybe you'd
be better not to mention the "tweak" word to anyone...
Invent a little white lie for them, say you think the MoDem
disconnects when you have something cooking and you're
too busy to mind about it when it ocurs... It's a real issue,
i've demonstrated the "Cooking Hour Syndrome" long ago:
A wire is a wire is a wire, Bicephale, 2007-Sep-8
%20.GIF)
Tweaks, Bicephale, 2008-Jul-7
Then, with a higher profile, it would make sense to fix your
wiring - at least it should be somewhat more motivating...
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dslrocker3
join:2002-05-26
Toronto
4 edits | Update: Bell just changed the profile again. It started off at 2496/800 fast path (with enough overhead to probaby be fine at 3008/800 or maybe even 3.5Mbps downstream), then 2496/640 interleaved, and now it is at 1728/640 interleaved with a downstream SNR of 9.00 dB, attentuation 55.5 using my 5200 E242 and 1728/640 rx snr 8.0, attentuation 58.0 using my ST516v6. However this profile change didn't really accomplish anything as I could have simply limited the connection rate using my other modem (Speedtouch 516)
I know I'm being cynical now but I have funny feeling that a technician isn't coming this time. On the positive side, my RX corrected errors have dropped form the thousands per 15 minute intervals to only 23 in the last 8 minutes. This still doesn't address the sudden loss of signal quality that resulted in drop of about 1000Kbps in attainable rate but at least it's stable now. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Re: Help/Advice with my Line Statistics please Hi,
If you have a demarcation box with this type of
connector module then it's perfect for testing:
When in use (with its protective lever aside) the
"testing" RJ-11 outlet is the only active element:
the pair of silver switches below it will disconnect
everything else attached to the orange section.
There should be no paradoxal behaviour observed
when testing from that location. | |
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dbsanfte
join:2005-03-15
Montreal, QC
·Colbanet
1 edit | FECs are just flipped bits that get automagically fixed via the wonders of parity. They don't cause retransmission of frames, and so don't affect speed. It's the CRC errors you need to worry about.
I get somewhere around 7 million FECs per hour, and yet only maybe 20 CRCs in that period, and a solid connection at 3.5dBm. | |
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| dslrocker3
join:2002-05-26
Toronto
1 edit | Re: Help/Advice with my Line Statistics please said by dbsanfte :FECs are just flipped bits that get automagically fixed via the wonders of parity. They don't cause retransmission of frames, and so don't affect speed. It's the CRC errors you need to worry about. I get somewhere around 7 million FECs per hour, and yet only maybe 20 CRCs in that period, and a solid connection at 3.5dBm. So I guess that means that the 45000 rx FEC is not a problem because they were corrected and that the 5 rx crc and 0 tx crc in the last 10 hours 20 minutes is minor. This is how it has been since the profile change down to 1728/640 and after I switched my SS5200 back to the ST516. | |
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Bicephale
join:2005-09-24 | Re: Help/Advice with my Line Statistics please FEC Errors are still representative of noise so these can
be useful when one wishes to detect daily patterns but
it seems to me another avenue is going to be explored.
Good luck! | |
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dslrocker3
join:2002-05-26
Toronto
1 edit | Just to clarify, I have no doubt that my internal wiring is really screwed up. At the demarc, the connection is screwed up too though when compared to what the connection used to be.
Bell did agree to send a techncian again tomorrow afterall. Something has happened to the line obviously when the maximum attainable rate on fast path suddenly went from about 3000 to maybe about 3300 Kbps all the way down to about 2100Kbps. if the techncian can prove the the sudden signal drop is on my end and he/she knows how to fix it, I might just have them perform that repair. Any idea of what the cost for something like this would be (rewiring)? | |
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ex bell
@cgocable.net
| Re: Help/Advice with my Line Statistics please I think the starting rate for ISW repair is $99.00 and up depending on how long he is there, plus materials.
It is next to impossible to get a straight answer from Bell on this.
I do ISW repairs and customers have been told been told so many stories from Bell I don't know what to believe anymore.
Remember that you can do the repair yourself or call a private guy.
There are ex bell guys in the phone book under Telephone Installation and Repair.
If you get Bell you are supposed to be able to get an estimate first. | |
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dslrocker3
join:2002-05-26
Toronto
2 edits | I'm not even going to ask.... pooring rain outside, miserable day and suddenly this happens... I wonder if it is something that changed on it's own or if Bell found a problem spot and did something. | |
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| dslrocker3
join:2002-05-26
Toronto
1 edit | Re: Help/Advice with my Line Statistics please ... and now with the settings tweaked a little...
I turned the target snr in DMT 7.35 down 2 notches from the default to what I believe tells the modem to accept a overall RX SNR of 6.0 dB to lower the relative occupancy. Does the Test Centre see that drop in occupancy of a few extra percent? I'm just trying to add a little extra overhead to convince them to allow the 2496/800 profile again. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Re: Help/Advice with my Line Statistics please Unless there's improvement with your wiring you'll have
a trade-off to make. 2496/800 Kbps would be a win-win
situation, no trade-off there so expect 2496/512 Kbps
Interleaved instead. Twelve dB DownStream SNR Margin
should make the Thomson SpeedTouch 5x6 stable. | |
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| | dslrocker3
join:2002-05-26
Toronto
4 edits | With the open trouble ticket, should I leave my Speedtouch 516 hooked up or have the Speedstream 5200 E242 connected intstead?
I just hooked the 5200 E242 and it is giving a SNR of a couple dB higher so that would appear to give me a little more of a buffer (at least when the Test Centre does a line test).
Status ATU-C Current Tx Rate
(bits/sec) ATU-R Current Tx Rate
(bits/sec)
UP 1728000 640000
DSL Statistics (accumulated at 15 minute intervals)
System
Time Tx
CRC Tx
FEC Rx
CRC Rx
FEC LOS SEF LOS
(sec) SEF
(sec) Err
(sec) Rx
(blocks) Tx
(blocks) SNR Atten.
00:01:23 0 0 0 0 0 0 0 0 0 4016 4016 15.0 55.5
Totals 0 0 0 0 0 0 0 0 0 4016 4016 N/A N/A
I'm wondering if the fact that it started raining somehow helped my connection (maybe a wet spot in the wiring but the rain moved the wetness elsewhere).
Update as of 6pm today: The Bell technician was here and said he found a slightly better pair at the OPI. He also found something rather interesting on the Bell pole at the back of my property and says that there was a "cross" on the line. He just left and said he will try his best to get my connnection routed to a stinger but he would otherwise have to send another technician from the cabling department. (LOL, funny how the first techncian concluded that there was no problem other than my supposedly defective modem). | |
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Deadpool
Go Sens Go
Premium,VIP
join:2001-03-29
Canada | Re: Help/Advice with my Line Statistics please PM me your phone number and I can check to see what your neighbourhood looks like as well. | |
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dslrocker3
join:2002-05-26
Toronto
| noise margin at 1728/640 has slowly crept up to 17.0 dB. I haven't been contacted by Velcom or Bell yet so I am assuming that the trouble ticket is still open. I'm hoping that the slight increase in noise margin is a sign that it is still a work in progresss. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
1 edit | Re: Help/Advice with my Line Statistics please Hummm...
I wonder what Deadpool thinks about "tweaking": is it better
to optimize RCOs or SNR Margins knowing one of Bell's worker
is going to take a look?... It's one or the other, no tweak can
make them both optimized but it would mean using the ST5x6
in any case.
 | |
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Deadpool
Go Sens Go
Premium,VIP
join:2001-03-29
Canada
·Bell Sympatico
| Re: Help/Advice with my Line Statistics please There's a GigE remote in the area that he needs to be transfered to, which Velcom has to request from Bell.
Once he's on the GigE remote his line will be able to attain 16 Mbps.
--
Disclaimer: If I express an opinion, it is my own opinion, not that of Bell or its related companies. | |
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dslrocker3
join:2002-05-26
Toronto
3 edits | Unfortunately, I don't really think I am in a position to be asked to be transfered to that remote because I had requested a transfer to one a few months ago and was denied. They simply changed the profile from 1728/640 up to 2496/800 at that time.
The last techncian that was here also phoned me when he was still in the area and told me that the request was denied this time because an open connection wasn't available (exact wording he used was "no extra pair available"). But then again, that could be interpreted as "no extra pair available for wholesale customer". At 1728/640 interleave, rx snr 17.0 dB, I should at least be able to get my 2496/800 back (would accept 3008/640 even if they had to leave the interleaving on).
In this whole episode, I've noticed that different modems handle different lines very differently. Everyone speaks so highly of the ST516v6 but my impressions are less than spectacular. At least for my line, the SS5200 E242 is able to connect at higher speeds by a few hundred Kbps. I know that part for a fact because of how my occupancy was always pretty much 100% while I was experiencing problems. I've also noticed that with a lot of errors, the E242 is fine if interleaving is turned on but can't handle it if you are on fast path. The ST516 -at least for me- was much more stable with errors on fast path in the sense that I was able to connect and peform normal web browsing activities. In the last day the noise margin on the receiving end went from 15 to 17 dB on the E242 but did not change at all on the Speedtouch 516, remaining constant at 13.5-14.0dB. The Speedtouch 516 did however report an increase of attainable rate of about 130 Kbps from 2658 to ~2790 Kbps so I think that the two modems might actually calculate noise margin differently. | |
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See 9 replies to this post |
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dslrocker3
join:2002-05-26
Toronto
1 edit | Funny how Velcom complained to managment and an hour later, I at least got the speed back before that I had before the problems started. At 2496/800, the noise margin flutuates between 9.5 and 11.0 dB. They left the interleaving on though but that's not that big of a deal to me.
Noise margin doesn't tell you the occupancy but I would think that it can give you idea of what percentage you are at (ie. 6.0 dB pretty much being 95-100%). Between 9.5 and 11.0 dB, I really doubt that the my RCO is 90+% like Bell claimed it would be.
Now my only problem is what to do with my ST516 (sell or keep because it is valuable for troubleshooting). I know that will probably barely be able to do the 2496 and will probably be around 6 dB with the ST516. I don't want to plug the Speedtouch in yet though because Bell might see the higher RCO. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Re: Help/Advice with my Line Statistics please Hi,
I don't concur about the value of SNR Margins but i do
share your concern about which unit should be on-line
while Bell looks around. Perhaps DeadPool can provide
some advice here - i've hoped that he might, actually.
 | |
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| | dslrocker3
join:2002-05-26
Toronto
1 edit | Re: Help/Advice with my Line Statistics please said by Bicephale :Hi, I don't concur about the value of SNR Margins but i do share your concern about which unit should be on-line while Bell looks around. Perhaps DeadPool can provide some advice here - i've hoped that he might, actually. I'm not saying that you can always go by the noise margin but in my case, I know that the Speedstream has consistently been able to connect at a higher download speed than the Speedtouch (when I was having problems Speedtouch would connect at 1856 Kbps but the Speedstream would connect at 1984 Kbps both reporting noise margins of about 6 to 6.5).
When I was at 1728 and after the connection had improved again, the noise margin was often at 14 for the Speedtouch with a RCO of 62% but the SNR went as high as 18dB in a few instances with the Speedsream. Since the the Speedstream has been consistently been able to connect at a higher attainable rate when I couldn't achieve the full profile speed and always reported higher SNR values than the Speedtouch, I am speculating that the RCO on the Speedstream was lower than the 62% reported by the ST516 at 1728Kbps. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Re: Help/Advice with my Line Statistics please I've taken a quick look at the RCO records i published and my ST516
won the contest against my ST546 which won against my SS4200...
On the other hand, i know from memory that the SS4200 still worked
with somewhat lower SNR Margins which made any of those STs fail.
But... The SS couldn't be tweaked while the STs could be forced to
stay connected long after that SS got overwhelmed by strong noise.
...
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dslrocker3
join:2002-05-26
Toronto
| It's a good thing that I had my Speedstream 5200 hooked up and not the Speedtouch 516 when Bell did the test to change the profile. Velcom tells me that I am at 87% occupancy with the Speedstream but when I hooked up the Speedtouch modem, it was only able to connect untweaked at 2432 Kbps. I have also noticed that the Speedtouch 516 does something odd when showing RCO on an interleaved line. It will never connect using more than 90-92% of the downstream part of the line. This restriction doesn't seem to be there with a fast path lilne. I beleive that ST516 miscalculates the RCO on an interleaved line by not factoring in the extra overhead for error correction.
By the way, isn't it possible that turning interleaved mode on actually drives up the occupancy of the line up?
Based on the way the old ST Home calculates occupancy, it was actually calculated based on the amount of line rate used up, rather than the ATM rate. Since error correction uses some of the line, more of the line would have to be used to connect at any given speed. I'm just wondering out of curiosity because it seems like to me fast path seems to generate a lot less errors than the number of corrected errors in interleaved mode on the same line. I'm just wondering if extra overhead brings the occupancy up driving the error rate up (but correctable). | |
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See 16 replies to this post |
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dslrocker3
join:2002-05-26
Toronto
2 edits | Hello again Bicephale
Look at what I found inside the TD-8841's brower interface:
"ADSL Tone Settings" for both upstream and downstream
Is this TP-Link and the D-Link 2320B basically the same modem? The tone selection page looks suspiciously almost identical to that in the D-Link 2320B message thread. The guy at Premier Computer Canada actually adviced me to take the TP-Link over the D-Link even though it meant they were selling a product that was half the price.
other features available:
-dsl type selction (g.dmt, g.lite, adsl2, annexL, ADSL2+, AnnexM)
-bitswapping
-SRA
-test mode (normal, reverb, medley, no retrain, l3)
I'll have to do some research and experimenting to see what all this stuff does.
Lots of nice "toys" on the TD-8841 with a very low price. | |
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See 14 replies to this post |
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dslrocker3
join:2002-05-26
Toronto
2 edits | trial and error #1
With all tones enabled:
synced at 2496/800
ds max 2848
us max 1004
disabled upstream tones 20-31:
synced at 2496/448, downsteram snr seems to have gone up about 0.2dB
ds max 2880
us max 596 | |
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dslrocker3
join:2002-05-26
Toronto
1 edit | trial #2
disabled tones 15-31
synced at 2336/256
ds max 2592
us max 352 Kbps | |
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dslrocker3
join:2002-05-26
Toronto
2 edits | trial #3
disabled tones 18-31
synced at 2496/384 ds snr up by about 1.0 dB compared to when all tones where enabled.
ds max 2912
us max 500
trial #4
diabled tones 19-31
synced at 2496/416
ds max 2912
us max 544
I know these numbers look like a big mess now and I know the next step will be to make a chart or spreadsheet but I'm just recording the results as they happen so that it is documented somehwere. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Re: Help/Advice with my Line Statistics please Additionally,
If you also cut the bins from 32 to 70 then we can
expect your DownStream rate to lower as well but it
would prove that you can manage in case Bell could
be convinced to put you on a much higher profile...
I don't know for you but i feel like i need a snack, do
you intend to tweak a little while longer? | |
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dslrocker3
join:2002-05-26
Toronto
| Yes, the URL is correct to take you to the stats page for the TD-8841 modem. That might come in useful for a FAQ so that the line statistics are easier to find for people who might try this modem. I suspect that it might even work for the dlink 2320B and the other modems that had similar interfaces/identical wording and tabs.
I really should try sleeping but this is kind of intriguing me now so I'll probably stay around for about another half hour or so. | |
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| dslrocker3
join:2002-05-26
Toronto
2 edits | Re: Help/Advice with my Line Statistics please I've noticed that this TP-Link 8841 is similar to the Speedtouch 516 in the way that it refuses to connect at speeds with a noise margin of less than 7dB. For that reason, it is rocks solid maintaining a connection once connected but this model seems very picky about the signals that it accepts and rejects. I'd be curious to know if there was a way on this model to change the target noise margin to 6dB as it is set with some other models (to give a little more extra space between the sync rate and the maximum possible sync). | |
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Bicephale
join:2005-09-24 | Re: Help/Advice with my Line Statistics please It would help to have a glimpse at its TelNet CLI, the
unit may be Broadcom-based just like the Thomson
ST5x6 but i doubt we can use the ST TelNet CLI bible
with it... | |
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dslrocker3
join:2002-05-26
Toronto
| here's the graph from orbmt when my tp-link modem is connected | |
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dslrocker3
join:2002-05-26
Toronto
4 edits | I didn't think that DSL Modem Tools would work on such a generic budget brand modem but here's the screenshot I was able to get. I found my noise margin tweak and I guess I can now force it to connect at 2496 for those times that the modem wants to only connect at a speed slightly lower than that set on my speed profile. The second screenshot was taken when the modem was told to accept even the crappiest signals.
While some other modems that always connect at 2496 on my phone line such as units with the AR7 chipset, I don't think it's a matter of them handling my line any better; I just think that they have the target noise margin set lower in the firmware.
So with this new found knowledge, I think I should be able to use this to my advantage. It's great because I pretty much have the flexibility of a Speedtouch 516 at half the price with this TP-Link model. Though this isn't my first exposure to this program, I didn't feel it was as useful for me when I had the Speedtouch due to way that model handled my line.
The only problem is that I really have no idea of what these graphs really mean. I'll do some searching now on this message board. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
3 edits | Re: Help/Advice with my Line Statistics please%20.GIF "38101 bytes")
DSLRocker3 - TP-Link TD-8841 Tweaking (2009-May-6) |
Thank you for posting your 'DMT v8.07' screenshots, it's
now clear that those of us who search for alternatives
based on the Broadcom BCM6338 ChipSet wouldn't have
to fear loosing 3rd-party SoftWare support: the TP-Link
TD-8841 CPE unit can be seriously considered as a valid
candidate for some future purchase!... 'OrbMT' already
allowed the owner to record animated .GIFs of spectral
response through time, 'DMT' opens the door to detailed
performance analysis via its powerful "Diagnosis" mode:
OrbMT on D-Link DSL 2320B, Bicephale, 2009-Feb-28
Additionally, both of the utilities mentioned above can
monitor the MoDem's parameters in order to intervein if
the BitRate and/or SNR Margin level(s) drops too much:
On top of that, you've shown that tweaking might work
as well: your SNR Margin vs RCO trade-off has affected
the estimated loop length by 2.75 %, after all; i find it's
permitted to hope for the best, provided Bell would give
the customer enough room to tweak, of course! Finally,
there's a feature on the "Info1" tab titled "Error Statistic
(last 60 minutes/15min.intervals)" in 'DMT' which looks a
lot like some kind of "noise" graph window to me... Also,
i wonder if the TelNet CLI will allow the owner to adjust
"Interleaving depth" but i'm not even sure which TelNet
CLI "bible" to use yet. This one is for a ZyXEL Prestige:
ZyXEL P-660 CLI Reference Guide
Oh, and thanks to 'DMT' we can safely assume it's OKay
to turn off tones 64, 123 and 136 to 138, by the way...
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| | dslrocker3
join:2002-05-26
Toronto
4 edits | Re: Help/Advice with my Line Statistics please said by Bicephale :Hi DSLRocker, Thank you for posting your 'DMT v8.07' screenshots, it's now clear that those of us who search for alternatives based on the Broadcom BCM6338 ChipSet wouldn't have to fear loosing 3rd-party SoftWare support: the TP-Link TD-8841 CPE unit can be seriously considered as a valid candidate for some future purchase!... There are some other Tp-link models that I suspect might have the same chipset that and wil be in the $20-$25 range. The TD-8841 costs about $10 more becaue it has 4 ethernet ports.
When dealing with my line conditions, I'm somewhat regretting contacting Velcom and having them open a ticket through Bell. While one of their techncians says that he found a voltage cross on the above-ground pole, another techncian tried to tell me I had a defective modem even though I've tried a few of them. The voltage cross issue is also what I was told before by another technician about 5 years ago and I was told it could be an issue in the future. I do not believe that any substantial repairs were completed to the line as the conditions started to improve again before the techncian even came to find the problem. He did say he did find a slightly better connection but I don't think that was at the root of my line issues. Supposedly, they were going to have the cabling department sent but no one ever came. It's possible that the line would have been able to conect again at 2496/800 like before even if the ticket was never opened.
The end result was that I got switched from fast path to interleaved. The Speedtouch 516 would connect at 98% of the attainable rate but both the Speedtouch 516 and TD-8841 will not connect at above 90-92% with interleaving turned on. That extra headroom that I lost can be valuable and it's possible that I might have been able to control any errors by simply tweaking. Switching back to fast path now will probably be next to impossible. | |
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Bicephale
join:2005-09-24
·TekSavvy Solutions..
| Re: Help/Advice with my Line Statistics please Hi again DSLRocker,
I just went through the whole thread rapidly to remind
me of the time-line and there are a few things still to
be addressed. 1st, i'd contact DeadPool and ask to be
put on 3008/512 Kbps Interleaved at least for a couple
days, while you evaluate your tweaking tools. Another
item on my mind is the paradoxal behaviour described in
your very 1st post: i suspect long-term "noise" curves
would reveal daily patterns and if so this would confirm
you should try to fix your phone-line wiring past Bell's
demarcation point... Last but not least, it's possible to
compare DSL device performances using noise curves...
Obviously, it was a bad idea to have Bell involved via
your ISP. My opinion is that you need to decide what's
coming next: trouble-shoot now then fix the phone-line
or vice-versa!...
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| | | planiwa
join:2009-02-19
Toronto M5S
1 edit | TP-Link Modem models and huge differences said by dslrocker3 :There are some other Tp-link models that I suspect might have the same chipset that and will be in the $20-$25 range. The TD-8841 costs about $10 more becaue it has 4 ethernet ports. FWIW, it appears that ...
Similar product line:
TD-8610 -- very limited modem, limited Web GUI and NO Telnet access ($25)
TD-8816 -- much better modem, better Web GUI and extensive Telnet access. ($30)
TD-8840T -- same as 8816, with 3 more Ethernet Ports ($35)
Different product line:
TD-8841 -- much better and totally different Web GUI than 8816. Has tweaking capabilities. ($35)
Too bad no one has said anything about the 8841's Telnet interface. | |
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Bicephale
join:2005-09-24 | Help/Advice with my Line Statistics please I've been waiting patiently since 2007 so i wouldn't
mind if somebody started an entire thread on them! | |
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