In reply to a post by AdrianPH:

Your TBB monitor graph looks familiar.

I left Zen because the FTTC connection was so erratic. Lots of packet loss and peaks of high latency.

My graph was showing lots of high blue and yellow spikes, even between 9.00 pm and 3.00 am, it looked like someone running large downloads.

This was every single day, thing is all our systems are off by 9.00 pm, WiFi is also shut down at night.

Moved to Uno , (still via BTW ) and the graph is clean, no big peaks, no packet loss , no speed changes.

My Zen connection looks pretty much the same as your Uno one, rarely there are some changes to average latency which seem to coincide with network reconfiguration in the early hours.

looks like congestion, but the source of the congestion no idea.

For the price zen charge, get them to fix it, if they cannot switch isp's.

interesting, maybe I will finally get round to ordering my backup broadband service then, with aaisp finally going ahead with talktalk FTTC.

Although pulse8 I have been seriously considering as they seem a good choice as well.

For completeness and to close out thread, the problem was confirmed by Zen to be a congested SVLAN and that the exchange back-haul capacity is at capacity awaiting an upgrade at end of Feb. I was moved to another SVLAN and that has helped a lot.