BT 21CN not fit for purpose?

Update: The BT Wholesale Incident Helpdesk manager has stated:
Please rest assured that BT Wholesale are fully committed to ensuring that all capacity issues are addressed.

I posted about this some years ago when BT had recently started their 21CN network. They had congestion in parts of their network and were refusing to believe it, let alone fix it.

Eventually, after the press got hold of my blog post, BT took action, and our monitoring graphs were used internally within BT where BT Operate staff were able to track down a series of errors and mis-configurations that were causing the congestion.

Following that (as we understand it) BT set up a new department to pro-actively manage the various links and perform necessary upgrades. Occasionally there are still issues, usually a mis-configuration or a fault and hence something BT do not pick up themselves. These usually get fixed once we report them.

Unfortunately there must have been a change of staff or attitudes in BT and once again we see core links within BTs networks showing congestion which BT are basically refusing to address.

Importantly these congestion issues are present even when paying extra for "business grade" premium services (elevated weighting) on the broadband tails.

We recently had a statement from BT that "3% packet loss is not considered a fault", which is outrageous. Despite being published on ispreview they have not refuted that statement. This was an idle line 3% loss all the time (which we believe we have tracked down to a fault on a core link within BT), but the suggestion that 3% idle line loss is not a fault is totally crazy.

Now it seems that serious back-haul congestion is also acceptable to BT. They insist on SFI engineers (who cannot test packet loss anyway) sent during the day (when the packet loss is not present).

The good news is that we don't see this on TalkTalk back-haul, and we, like you, have a choice. If we have to move all customers on a congested area to Talk Talk back-haul to fix this, we will. I am sure other ISPs can do the same.

What is even odder is the comment from a senior member of BT plc staff, Neil McRae, that it was "rubbish" and  "there are no BT exchanges at all that have any congestion". I pointed out that we have clear evidence of exchanges where all 21CN show packet loss, i.e. "Every line we have on Hampton exchange shows signs of congestion". At the suggestion it was the SVLAN not the exchange I said "If you say it not the exchange it is the SVLAN, then that is the same thing - if the pipe to the exchange is getting full, then that is congestion at the exchange". I was told "no" and "but if you want to be stupid then I won't argue with you". These are the comments from someone that describes himself as Chief Network Architect at BT.

We know there are exchanges showing serious signs of congestion, such as Coventry, Hainault, Southwark, Canonbury, Loughton, where 21CN lines are showing loss in the evenings.

We have, of course, confirmed that this is real and general problem by checking with other ISPs, who are also chasing BT

Update: For one area BT have stated: "The issue that is currently causing packet loss and slow speeds to end users is with the backhaul links being over utilised. In relation to over utilisation, we are talking about ports or lag groups trying to send more than 100% of their capacity. When the buffer on these ports or lags fills up, it will cause packets to be dropped." confirming BT have congestion in their core network.

The question from me:

This is a really simple question for BT plc: Are BT going to formally commit to addressing congestion faults, or do we (and other ISPs) need to start moving people to an uncongested network like TalkTalk wholesale instead?

Example of a line on Canonbury exchange over the last week