Interleaving suddenly enabled - advice please!

Hi,

I've had a solid 79995 / 20000 sync on my line for the last year, with no disconnects / reboots in about 2 months. This morning at around 6.30 my Draytek 2860 reported a disconnect / reconnect, and now I'm connected at 74728 / 20000 with an Interleaving depth of 1089! This seems very odd to me - as I understood it, interleaving would only be applied on a line with clear instability, which mine definitely doesn't have. I have tried a reboot in the meanwhile but nothing has changed.

Any idea what may have happened here, and moreso how I could report this issue to BT (my ISP) without getting fobbed-off? I'm less bothered about the 5Mbit drop but really don't want the unnecessary Interleaving. My attainable rate is showing as 86475 which is even stranger. If it was during working hours I'd have thought someone made a manual error but this confuses me.

Thanks in advance!
Mark

I can only guess that your line has been experiencing errors and DLM has decided to apply interleaving improve stability

In reply to a post by BatBoy:

I can only guess that your line has been experiencing errors and DLM has decided to apply interleaving improve stability

Right, that would be my usual guess. But it's had zero disconnects in 2 months and is typically very stable. Could I have a bunch of errors without a disconnect??

Any thunderstorms around last night?

On FTTC, as well as interleaving lowering the connection speed it does strangely always raise the maximum attainable.

Do you know whether you are on an Huawei cabinet or an ECI FTTC cabinet?

If it's ECI I'm not sure what might happen next. Possibly the interleaving will be removed in a while. On Huawei I think it likely that G.INP will be activated within three days. That will leave you with a small level of interleaving and return your latency to what it was before, as well as adjusting the connection and attainable speeds to normal.

In reply to a post by Bluestraw:

But it's had zero disconnects in 2 months and is typically very stable. Could I have a bunch of errors without a disconnect??

It must have disconnected. Those changes could not take place without one. If you are monitoring with DSLStats it won't notice it, except for the speed change and perhaps the noise margin, as its shortest sampling interval is 1 minute. A disconnection and re-sync typically takes more like 20 seconds.

RouterStats and RouterStatsLite (I use the latter) can sample as frequently as every 5 seconds, which is how mine is set.

Edited by RobertoS (Tue 06-Jun-17 13:32:23)

Yes. Errors and disconnects are separate events and different actions will result. If you have too many disconnections then DLM will cap your connection speed to increase the SNRM.

Thanks everyone. What I meant about the disconnects is - I had ONE single disconnect this morning, after 2 months with zero disconnects (I have uptime stats on my modem). So I was shocked to find DLM applied after just a single disconnect / reconnect. Heavy rain and wind last night (no thunder) so could the line have had enough errors to force DLM so quickly?? Here's my cabinet - anyone know if it's Huawei or ECI?

Cabinet

That's an ECI cabinet.

ECI. The black one on my linked page.

In reply to a post by Bluestraw:

Heavy rain and wind last night (no thunder) so could the line have had enough errors to force DLM so quickly??

DLM monitors errors and disconnections over a 24 hour period then takes action the next day if the limits are exceeded