Lower minimum latency with new modem

After a scare earlier this week caused by Community Fibre contractors killing our voice/FTTC line whilst installing a pavement chamber, it transpired that my old ECI Openreach modem was not in a happy place.

As SWMBO works from home and I do on occasion as well I decided to bite the bullet and source a decent replacement rather than a Fleabay offering.

I plumped for the Draytek Vigor 167 which arrived the following day and after updating the firmware via my PC dropped it into my setup as a slot in replacement.

It worked perfectly first time and out of interest I had a nosey at my BQM for that day.

To my surprise (a pleasant one I may add), my minimum latency (the green "floor" section) had noticeably dropped which I definitely wasn't expecting at all.

You can see it for yourself via the following (look at the green level before and after the short period of disconnection in red.

My BQM

Edited by Memphis (Sat 29-Oct-22 22:14:43)

Do you know what chipset the Draytek uses?
I would guess it is Broadcom. I've always used an unlocked HG612 which is Broadcom based I believe and also see around 7ms latency on BT VDSL.

I can't see your BQM because it's been more than 24 hours but if the drop in latency was 8ms then it's because interleaving has been removed from your line.
Openreach add 8ms delay with their low interleaving on FTTC.

If the drop in latency was immediate then it will probably be because the Draytek is taking advantage of G.INP/Retx.

If you post the xDSL statistics from the Draytek it would give more of an insight in to what's going on.

The old ECI modem uses an old Lantiq/IFTN xDSL chipset.
Intel has since bought Lantiq.
The Draytek 167 uses an Intel xDSL chipset. Much newer, better performing and supports more standards.

Edit: scrap that. I assumed the BQM linked was your live graph. I didn't even notice the latency change.
It's pretty insignificant and might be the old ECI was adding a tiny bit interleaving/delay which some Lantiq chipsets often do.

Edited by j0hn83 (Mon 31-Oct-22 16:23:25)

In reply to a post by j0hn83:

I can't see your BQM because it's been more than 24 hours

The BQM is still there for 27/10/2022 and you can see the lower latency after the disconnect although its 1ms improvement at most.

In reply to a post by dect:

In reply to a post by j0hn83:

I can't see your BQM because it's been more than 24 hours

The BQM is still there for 27/10/2022 and you can see the lower latency after the disconnect although its 1ms improvement at most.

Wow, I assumed it was a live BQM as I was looking for a significant drop in latency. I didn't even notice the change.

I did have to get my magnifying glass out to see it, the minimum latency before and after the disconnect seems pretty good for FTTC.

Yep I don't think our line has had interleaving for any appreciable period on it as we're literally around 50m from the cabinet which is at the end of our road.