First 10 days

I understand there may be speed fluctuations in the first 10 days and I'm sure I have read (I have read lots, maybe too much) that I need to keep my (engineer supplied) modem and my router on for those 10 days - is that entirely necessary?

FTTC is a little different

First 48 hours are important, but really on the openreach modem is the thing that needs to be connected and working. The router can be rebooted etc

The speeds can and do vary forever as the VDSL MUST react to bursts of noise and things like crosstalk over the life of the line, just like with ADSL and ADSL2+

Thats great. Thanks

In reply to a post by MrSaffron:

The speeds can and do vary forever as the VDSL MUST react to bursts of noise and things like crosstalk over the life of the line, just like with ADSL and ADSL2+

In fact DLM actually seems to work on BT's FTTC/VDSL implementation.
Or, at least, it works in both directions (unlike ADSL DLM which only ever seemed to increase margins and reduce speeds).
Ever since getting FTTC (around 18 months ago) I've had full speed (40Mbps, then 80 when that was rolled out), with few - if any - unforced resyncs.

Over the Christmas period my sync dropped by around 20Mbps, with the IP profile following it, and stayed there (regardless of daytime reboots, etc.) yet almost 5 days (to the hour) from my last forced reboot, my speed is back up to where it's always been and the IP profile has immediately jumped back up.
My guess is loads of tacky external Christmas lights between here and the cab.

Whatever it was, I'm happy to report BT's DLM doesn't seem anywhere near as broken as it was on ADSL

Edited by adebov (Mon 07-Jan-13 17:17:24)

the much improved part seems to be now that ip profile tracks the sync speed better and that its instant on a ppp connection. I cant really comment on the DLM side as on adsl I was on a hideous connection due to E-side noise ingress. So now its different line behaviour the new DLM is dealing with.

You actually have two DLMs operating there.

2? Where?

The UK; Europe; The World; the Solar System; the galaxy; the universe.

Sorry Roberto,

In reply to a post by RobertoS:

You actually have two DLMs operating there.

Can you explain in what way are there 2 DLM's?

The Openreach DLM controls the line connection. Banding, noise margins, interleaving etc. This applies to all GEA connections, currently BT Wholesale, Sky and TalkTalk.

For BT Wholesale-using ISPs, on initiation of a new PPP session the BT Wholesale DLM, (the normal WBC one modified for this purpose), queries the sync speed and sets the IP Profile appropriately.

The WBC DLM also seems likely to be able to pass ISP-requested stability and traffic priorisation settings back to the GEA system.

Edited by RobertoS (Tue 08-Jan-13 13:19:27)