One loss of sync event and BT go mad

From 1 LOS event BT decide that I must be on a 9db profile rather than the default 6db and slightley less sync speed.

This 21cn DLM really really sucks.

IamQ, the 21CN DLM looks at more than the loss of sync but also looks at transmission error's on both the upstream and downstream. Its possible the line has been suffering such errors but not dropping. However if this is causing issues for you on the 9db profile PM me your username and I will see if I can get something sorted for you.

Its already been reset onec but started going south again a few weeks after.

Some time this morning it saw a dip in SNR down to 2dB and the router let go of the line. Errors are low and I'm fixed on fastpath.

I've had this happen before with this line, one (requested) reboot of the router gave me a 9dB margin which never recovered back down again.

I fear there is little point in doing anything with it now, im waiting to hear back from someone about early access to fttc, or one of the on-going trials.

Failing that if the line gets any worse then I'll have to look at going over to full LLU without any of the BT DLM sillyness.

and guess what - now I'm on a 12dB margin...

you have PM mail...

IamQ,

Looks like Aaron has you covered. The new 21CN DLM has been implemented to adjust line speeds with more than just SNR profiles. I wont go all the way into it, however as Aaron stated the line may/does have transmission errors and the DLM is trying to adjust these.

It will keep adjusting the line till it finds the profile that works. What we can do is help remove the reason for the adjustment.

In reply to a post by Azzaka:

It will keep adjusting the line till it finds the profile that works. What we can do is help remove the reason for the adjustment.

Indeed - lets hope between us we can as last time I tried to progress this with BT they had no interest what so ever and say there is no line fault. I had tried to get it sorted a long time ago, but that fell on deaf ears somewhere within Zen land when I first tried to get something done. It was only after the shift to 21CN its got worse and I've already had 1 margin reset.

As you say - its down to finding a fault (If anyone will actually do anything)

Just sent Aaron a message back anyway - and I'll chase this up with CS tomorrow once I'm back in the office.

Thanks guys.