odd speed jump after power outtage in local area ?

For the last 2 years ive only been able to achieve speeds of 62/14 on my 80/20 package, Our leccy when off just before 12 last night for 2 mins max and when it came back on i ran a speedtest it was showing 69/19 and 12 hours later its now showing 68/19 .... i dont understand where the speed jump came from can anyone explain ?

https://www.speedtest.net/result/8983913852.png

My Broadband Ping

Edited by beefcakechipz (Mon 27-Jan-20 12:59:48)

I've seen the same thing- last year we had a series of power failures due to a weird cable fault that the leccy board had difficulty locating, and after each failure a speed test would show ~73-75Mbps. It would maintain that speed until any "normal" re-sync, when it would revert to the usual ~68-69Mbps. Then go back up after the next power failure

Only theory I could come up with was that everybody else on my cabinet was re-syncing at the same time, and that the cross-talk noise caused by that was lower than when all the lines were up and running normally. But the increased noise when everyone was connected wasn't enough to cause the DLM to throw its toys out of the pram.

But I'm open to more informed suggestions

Post deleted by beefcakechipz

Ive noticed that when running speedtests my latency is much higher since the power outtage... how long will it take for the re-sync to pop things back to how they was ?

The speed jump is nice but the latancy is not

My Broadband Ping

My "base" latency (~10msec) didn't change after a failure, but the jitter increased from negligible to around a couple of millisecs... as I've got a very good line anyway and I don't do gaming I wasn't bothered

My Broadband Ping

Have you tried a manual re-sync? On mine, that would put the speed and latency jitter back to where it was before; waiting for the DLM to do it could have meant it never happened.

Is a manual re-sync where you power down modem for a few mins ?

That's it, but even a few seconds will do it- you don't need to wait for minutes.

Thanks Billford i have done just that and my speeds are back to 62/15 just hope the ping and jitter is back to normal now, i will check bqm in a couple of hours time

I've seen similar behaviour with the occasional power cuts in my area. Along the same lines I would imagine that when your modem negotiates its line rate there is less crosstalk from other users and hence you get a higher speed. If you were to check your SNR you may find it lower than the target 3-6dB and possily more errors. I imagine there is less crosstalk because some modems take longer to boot and hence start negotiation their line rate.

I use a good old Huawei HG612 separate modem - it tends to boot in around 60 seconds and usually negotiates the full ~80/20 Mbps after a powercut - but usually shows 1.5dB SNR and a few errors. It often gets a resync a day or 2 later down to ~68Mbps although occasionally it holds it for a few weeks/months!s

In reply to a post by adrenalize_:

I've seen similar behaviour with the occasional power cuts in my area. Along the same lines I would imagine that when your modem negotiates its line rate there is less crosstalk from other users and hence you get a higher speed. If you were to check your SNR you may find it lower than the target 3-6dB and possily more errors. I imagine there is less crosstalk because some modems take longer to boot and hence start negotiation their line rate.

I use a good old Huawei HG612 separate modem - it tends to boot in around 60 seconds and usually negotiates the full ~80/20 Mbps after a powercut - but usually shows 1.5dB SNR and a few errors. It often gets a resync a day or 2 later down to ~68Mbps although occasionally it holds it for a few weeks/months!s

You could well be right- I'm still using the old HG612 as well, it still works and I prefer separates so why change it?

Mine seems happy to hold the higher sync for ever (unless something else irritates the DLM) so the SNR may be a bit better than yours, but the principle sounds right. (I haven't hacked it so can't check the stats.)