DSL Resync Command?

Hi,

I was somewhat surprised that the usual subjects don't seem to work.

clear int atm 0 Does not force a re-sync.

clear int dialer 1 does force ppp to restart.

Even: int atm 0 shut

leaves the DSL in the "Showtime" state and the CD light on.

One way that I did mange to force it was to change the operating mode.

BT in the UK seem to support both dsl operating-mode ansi-dmt and dsl operating-mode itu-dmt

I usually specify dsl operating-mode auto.

This would clearly be a bit dodgy remotely over the dsl line since it may never work again.

I am on 12.4(8) mainline.

Maybe there is no need for this?

Hi there,

Aye I tried those here, too, shutting/clearing interfaces, though could only manage to drop/restart the PPP side of things. Switching the 'operating-mode' appears to work though as you suggest, cheers for that. I found I can switch between auto/ansi/itu to force a resync.

I'll only be performing a resync locally. :)

I've had noise issues with the line and so felt the need to resync now and again in order to observe differences in output from a 's dsl int atm0' command, which only appears to refresh during initial sync (I didn't manage to locate a command to refresh this info either). SNR here can fluctuate wildly with sporadic noise at times so a look at bin allocation and such has been a part of trying to determine what's going on, amongst other things.

Thanks again for the workaround.

Hi.

I tried on a C837 to shutdown the ATM0, and after I shutdown it the CD led turns off.

If I put it again with "no shutdown" the led will blink and then stay fixed on.

What software version are you using?

As I said I am on 12.4(8) [i.e. mainline].

User said:- "Aye I" - where does this come from?

Also - you may want to consider:-

int atm 0 dsl enable-training-log

I have no idea what the output means and some cisco document says (IIRC) that this may extend the time taken to "train".

Produces loads of weird stuff in the sh dsl int atm 0 output though. Quite satisfying but completely unintelligible.

Aaron?

Hi Aron,

I have a theory about what is happening here...

I am using an older 827 with (C820-K9OSY6-M), Version 12.2(15)T12 and I did notice that even if you SHUTDOWN the ATM interface, and it shows as DOWN, it does NOT seem to deactivate the "ADSL-CD" LED until the ATM re-sync process fully completes. As a DSL Negotiation cycle can take about 2-3 minutes to complete, this may explain why SHUT on a DSL line is not instantaneous like most other interfaces. You just need to wait a while........;-)

A debug of ATM events should show it cycling through the various stages and the LED will probably go out when it gets back to step 1.

Cheers................pk.

Interesting. I found if I 'shut' ATM0 here the CD light remains active (using IOS 12-3.4T).

I'm running IOS 123-4(T) here. I'd like to try a newer version though I'll be needing more memory as the C837 I'm using only has 32MB installed by default.

Manchester, UK. Just another way of saying: "Yeah, I..." or "Yes, I..." :)

Aye, I've used that before though, like yourself, have as good as zero understanding of any of it. =]

As an aside I found that if I enable the training log, 'shut' ATM0, then 'no shut', nothing appears in the log (as I suspected) as the line never drops to resync. It just states:

"Training log enabled, but not collected yet, beacuse there have been no state transitions since log was enabled. You can force a state transition through unplug/plug DSL line."

I can only guess at this point that no provision was made to enable forced resync of a line via IOS command given the "unplug/plug DSL line" bit, at least with the IOS version I'm using.

Thanks for your time.