bk_856er
join:2007-06-08
Palo Alto, CA
| reply to Doctor Olds
Re: OK stats, but frequent loss of sync
I invested about 3hrs tonight testing the modem noise margins under various conditions. I unplugged virtually everything in the (small) house, monitored the readings for a good bit, and then one by one added things back in. The bottom line is that nothing really made a consistent difference. I did learn that over a longer space of time my downstream noise margins can range between 7db and 16db, and at the low end sync gets iffy. Things are happy at 13db.
On a few occasions the downstream noise margins slowly decreased from 15db to 7db over about 15 minutes with eventual sync loss. Sort of a death spiral. When sync returned automatically a short time later the noise readings were back to normal.
During some periods of consistently low noise margin readings, if I "reset ADSL" with the web interface the noise margins returned to good levels with the new sync. It seems as if some connections are good and some are poor and are doomed.
At one point I thought that things might be correlated with the refrigerator running, but that too proved to be inconsistent. Nonetheless, I think I might benefit from a UPS with a line power conditioner.
I can't find a definitive "in-house" RFI cause for my occasional sync loss, but now I have a better feel for the behavior and I can rule out a bunch of stuff. On the upside, my installation is now very professional looking and strictly according to best practices! That alone might give me the slight edge that I need to stabilize a marginal line.
I tested out the zyxel telnet features. The mode change to GDMT is not a menu item, but is invoked with an undocumented "wan adsl opencmd gdmt" command according to Covad. Anyone know the command to restore ADSL2+ mode? I'm going to hold off on changing the mode until I know how to get back to where I am now.
Bob |
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Doctor Olds
I Need A Remedy For What's Ailing Me.
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join:2001-04-19
1970 442 W30
clubs:
3 edits | A reset should bring the unit back as delivered. 
»Re: Zyxel P660R-ELNK stability issues...
said by chrp2007  :try this - thanks to e_dub at covad.direct forumopen your command prompt and type: telnet 192.168.1.1 the password should be: 1234 you will see a list of menus, type 24 and hit enter another list of menus will appear, type 8 and hit enter you see a flashing cursor at the bottom of the screen; here you will enter: wan adsl opencmd gdmt hit enter. (once you hit enter your modem will lose sync because of the change. it will regain sync.) you will be taken back to the flashing cursor. type exit to back out, your now done. just exit out of all the menu thus exiting telnet. I also added this info to the Earthlink FAQ:
»EarthLink DSL FAQ »How to set the P660R series to use the G.DMT DSL Standard only? |
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bk_856er
join:2007-06-08
Palo Alto, CA | Nice work!
Wow, the link mentioning the "ring loop imbalance" with gradually decreasing downstream S/N readings sounds very similar to my death spiral.
I'll try the GDMT tomorrow.
Bob |
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DSum
join:2009-07-01
Los Angeles, CA
| Hi,
I don't have a solution for bk_856er, but I have similar problems.
I'm in West Los Angeles, CA, three blocks from the CO. No problems for years with a Zyxel Prestige 645M (yes, a 645M, not some flavor of 660 or a 645-UHP) with Covad/Verizon.
Then two weeks ago I started losing sync randomly, sometimes for a few minutes, sometimes for half a day. No sync for most of Friday, then it worked all weekend when I used it heavily, but then not at all Monday, 50-50 on Tuesday.
I don't want to "hijack" this thread with my problems (I'll start a new thread if needed), but Bob may not be alone and I'm curious to see what eventually works for you.
Dale |
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Doctor Olds
I Need A Remedy For What's Ailing Me.
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join:2001-04-19
1970 442 W30
clubs:
| Your Modem is a Bridge and you have to use Telnet to obtain the DSL Stats.
»EarthLink DSL FAQ »How do I access my Earthlink/Covad ZyXEL P645 modem (Bridge Model, not UHP)?
The commands to run in Telnet are in bold in the example below.
quote:
ChangeMe> wan adsl chandata
near-end interleaved channel bit rate: 0 kbps
near-end fast channel bit rate: 3008 kbps
far-end interleaved channel bit rate: 0 kbps
far-end fast channel bit rate: 384 kbps
ChangeMe> wan adsl linedata near
relative capacity occupation: 88%
noise margin downstream: 6.5 db
output power upstream: 12.0 dbm
attenuation downstream: 47.5 db
ChangeMe> wan adsl linedata far
relative capacity occupation: 59%
noise margin upstream: 16.0 db
output power downstream: 20.0 dbm
attenuation upstream: 31.5 db
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What’s the point of owning a supercar if you can’t scare yourself stupid from time to time? |
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bk_856er
join:2007-06-08
Palo Alto, CA
| I contacted Zyxel and obtained the last firmware that Earthlink provided to them for the -ELNK flavor modem. After installing the update (twice) the version reported is the same as before. Bin file was "P660R-ELNK-340AHC3D0." I need to contact Earthlink for something more recent if it's available.
Next I put the modem into GDMT mode. The downstream S/N and attenuation improved immediately! The latest stats are below. Time will tell if the connection is more stable, but I like what I see so far!!
System Name:
ZyNOS F/W Version: V3.40(AHC.0) | 11/16/2005
DSL FW Version:TI AR7 05.00.03.e6
Standard:Multi-Mode (does not show G.DMT mode??)
noise margin upstream: 18 db
output power downstream: 16 db
attenuation upstream: 31 db
noise margin downstream: 19 db (highest ever!)
output power upstream: 12 db
attenuation downstream: 60 db (lowest ever!)
SpeakEasy speed test performed today after the changes:
Download Speed: 1288 kbps (161 KB/sec transfer rate)
Upload Speed: 322 kbps (40.3 KB/sec transfer rate)
Bob |
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Doctor Olds
I Need A Remedy For What's Ailing Me.
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1970 442 W30
clubs:
| There is this, but I don't know what it is for version wise:
»support.earthlink.net/download/broadband/
quote:
EarthLink DSL and Home Phone Service Firmware:
* Zyxel Firmware Upgrade - Windows Download
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What’s the point of owning a supercar if you can’t scare yourself stupid from time to time? |
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bk_856er
join:2007-06-08
Palo Alto, CA
| That's too funny. I just spent 20min with Earthlink support and they were adamant that no firmware update exists, although they were eager to sell me a new modem. I can't get past the password request for that link using my Earthlink info. Anyone know what filename resides there?
Bob |
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Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
clubs:
| said by bk_856er : I can't get past the password request for that link using my Earthlink info. Anyone know what filename resides there? I can't either. Don't know why and I tried all 8 of my accounts credentials starting with the main account username/password. Strange. Also don't know the filename.
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time? |
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bk_856er
join:2007-06-08
Palo Alto, CA
| I chatted with support again and tried to get access to that specific page. Waste of time. They insisted that modem firmware is "upgraded on the server end when the modem powers on" and then finally that only their "engineers" can access that page. None of their info was accurate in the least, so I don't believe any of it. That link is taunting me!
At any rate, I now seem to have the original firmware file from Zyxel, so maybe I can risk trying the retail D1 firmware and then downgrade if I run into trouble. Then again I might savor my new connection stability for a while longer. I've bricked a device or two in my time with botched firmware updates...
Bob |
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bk_856er
join:2007-06-08
Palo Alto, CA
| So far, so good with the GDMT mode....
I'm thinking of experimenting with a different modem than the P-660R-ELNK that I'm using now, and possibly "upgrading" to something else for maximum robustness. I already have a good router/gateway, so my needs are simple bridge mode, and I have enough know-how alter the settings.
Is there a superior modem that'll play nicely with the ELNK LPV service?
Bob |
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bk_856er
join:2007-06-08
Palo Alto, CA | Pulled the trigger today on a Covad-approved Innoband ADSL2/2+ VOA Firewall Gateway 8860-C1. Looks like a nice unit that'll cover my router needs. I'll post up after I put it through its paces.
Bob |
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Doctor Olds
I Need A Remedy For What's Ailing Me.
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join:2001-04-19
1970 442 W30
clubs: | Sounds interesting. Please update us when you get the chance. |
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bk_856er
join:2007-06-08
Palo Alto, CA
| I received the Innoband 8860-C1 today and just set it up. The first impression is good and there were no glitches integrating it into my network. However, for some reason the modem is reporting 1.0/384 instead of my usual 1.5/384, with corresponding lower speed tests. Downstream attenuation is down (56dB) and downstream margin is currently 9dB. I'll update again with more details after I get some additional experience with the unit....
Bob |
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Doctor Olds
I Need A Remedy For What's Ailing Me.
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join:2001-04-19
1970 442 W30
clubs: | That's a bad sign. It should sync at the same rate as your other Modem. If you plug the other Modem back in, do you regain the 1.5 Sync Rate? |
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bk_856er
join:2007-06-08
Palo Alto, CA | I'll swap modems tomorrow. I power-cycled the Innoband and now it syncs at 1.1/384. Weird. I'm no expert, but I assumed that the modem should sync with the DSLAM port setting, which according to a check by Covad just the other day was 1.5/384... |
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Doctor Olds
I Need A Remedy For What's Ailing Me.
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join:2001-04-19
1970 442 W30
clubs:
| said by bk_856er : I assumed that the modem should sync with the DSLAM port setting, which according to a check by Covad just the other day was 1.5/384... That is what it is supposed to do.
You may need to inquire with »innoband.com/support/contact_support.php
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What’s the point of owning a supercar if you can’t scare yourself stupid from time to time? |
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bk_856er
join:2007-06-08
Palo Alto, CA | Thanks for confirming the proper sync behavior. Before I posted here I put an inquiry into Innoband with all the modem data and configuration, so we're on the same page. I see that you are a night-owl like me! |
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bk_856er
join:2007-06-08
Palo Alto, CA
| Slightly off-topic, but does anyone have an opinion of this Wilcom device?
»www.wilcominc.com/Item.cfm?ProdID=108
I currently use their PS-15S POTS wall-mount ADSL2+ splitter, but the "advanced filtering" claim of the DSL600-PS unit caught my attention. Maybe it would clean up my line a little and increase my downstream margin?
Bob |
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Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
clubs:
| said by bk_856er :I currently use their PS-15S POTS wall-mount ADSL2+ splitter, but the "advanced filtering" claim of the DSL600-PS unit caught my attention. Maybe it would clean up my line a little and increase my downstream margin? Yes, they make very good products. As to any additional cleaning of the signal above what you already have, I cannot say if that is accurate or just sales talk. It can't hurt to try unless it is prohibitively expensive. 
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What’s the point of owning a supercar if you can’t scare yourself stupid from time to time? |
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