Selected ISP Support > Covad / covad.net > Firmware rasied noise margins on 643

reply to gdm

Re: Firmware rasied noise margins on 643

reply to gdm
Have you guys inquired in the Zyxel forum ?? Maybe there's a Zyxel tech who hangs out there and can comment on this...
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-= Mindspring MaxDSL via Covad 1536/384 TeleSurfer Pro =-

Hall,

Bill posted something there a few days ago no real response.

Hall, ZyXEL is one of Alcatel's many partners. The Alcatel chipset does all the telco part of ADSL, probably with DSP processing - ZyXEL plants that chipset in their product. That technology (implementation of ADSL) is pretty closed and proprietary. Chances are, Alcatel sends a block of code to ZyXEL (known as Version 3.8.164 for example) which ZyXEL puts in their firmware to send to the Alcatel hardware to run with. I'll bet ZyXEL knows little about the code they use.

But you'd think f/w enhancements would be passed along. I did notice one Alcatel update ZyXEL had a problem with and removed from one product. Also, every ADSL modem ZyXEL makes seems to run the same Alcatel firmwares - indicating they probably ALL use the same (or very similar) chipset. I looked at quite a few, looking for any products mentioning Alcatel Version 3.8.164.

reply to Hall
Hall, besides all that I also replied to the wrong person, apparently.

Oh well... no FastPath for me (sigh)

Bill,

That sucks but the firmware still helped though besides the primetime, correct?
[text was edited by author 2003-04-12 16:55:47]

The firmware seems to measure noise margin differently and/or possibly retrain quicker or smarter. ADSL is an array of frequencies that can be selected or discarded based on signal conditions. Since it's quite dynamic it's hard to say what's going on, really. All I do is come up with a zillion questions only insiders can answer.

For example, that 1AM recovery - was it the noise going away or did the modem recognize the noise problem and re-train? When I get some time I want to try to get more insight.

Are you brave enough to try non-Safe-Mode yet ??

said by Hall:

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Are you brave enough to try non-Safe-Mode yet ??

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reply to Hall
OK, you guys win. I'll call sometime soon and give it a try. I've done enough creative justification.

There you go Bill!!!!! Let us know what happens and all the stats. Nothing like a little presssure.:)

That friday night dip still seems very strange to me. I thought no matter the usage a DSL line shouldn't spike/dive like that. Bill I know you said they have checked the line and everything else.

Do you know if anything is going on at the CO at this time? It's every friday night, correct?

No, it's not every Friday night. Loss of sync tends to occur around high residential phone usage times historically here. This includes week nights, weekends and holidays. Not always, just most-the-time.

This is across (supposedly) at least 3 different dry pairs and 2 line-shared pairs over 5 years or so. It's also on both Ameritech and (now) Covad DSLAMs.

This is the first time I've seen data indicating what looks like a similar pattern. Notice the small dip Saturday before noon - that's typical, too. Sunday can be bad but not this week.

No, I didn't loose sync *every* Saturday (EDIT: Friday!) night. It was just one of the times I typically would. Get the idea?

Something at the CO can certainly affect only the higher ADSL frequencies and, thus, downstream to me. However, upstream at lower frequencies ("Upstream noise Margin") stays locked at 16db. You'd think it would affect reception there.

Too bad I can't replay Friday night in FastPath. I hate data speculation.
[text was edited by author 2003-04-14 20:27:34]

Bill,

Ok I got you now. I still can't believe high phone usage would cause this issue. I don't know enough to say yes or no but just find it hard to believe.

If you saw the 1-1/2 miles of buried 60-year-old phone lines near me you would. No phone tech EVER wants to go down in that hole and they never do - they just swap out pairs until things settle (sigh). My theory has always been cross-talk due to old, damp, wire bundles. Anything to my house has to go through this mess.

EDIT: Then there's creative phone servicing. Notice I said "supposedly" 3 pairs. Well, "supposedly", I had bridge-taps removed, pairs swapped, etc. etc. several times back in 1998 trying to fix me. Funny... no interruption looking like such ever occurred and I ping-test every 15 seconds. They must be MAGIC! (off the sarcasm for now ).
[text was edited by author 2003-04-14 20:42:41]

That's right I forgot about the OLD phone wiring in your area. Never mind I am done responding about your drops now:)

Oh, I forgot to say 784/784 SDSL was *solid* on the same dry pair Ameritech ADSL was bad on.

And my standing offer to any phone company insider. A steak dinner for the guy/gal that finds me a clean ADSL line! (it's audibly perfect already).

Just an Update