I've got a Zen ADSL connection that's been stable for some years now at ~15mbps down/~1mbps up. For the last couple of months or so I've had a problem whenever I upload files, either using Dropbox, backup programs or anything uploading non-trivial files. Specifically, the ADSL connection drops and has to reconnect - usually takes a minute or two, and interrupts whatever I was doing.
I've gone through various things with support over the last 5 weeks. Microfilter, test socket, the usual things ... none of them solved the problem. I've now been told that there isn't a fault and that my usage is the problem. I've been told that it's normal for upstream saturation to cause the ADSL (sometimes at the PPP level) connection to drop. I'm not a network engineer, but I've been using ADSL for over a decade and never seen this happen. A question for the experts - is this actually a real thing with ADSL? I know that upstream saturation can cause problems at the TCP/IP layer, but not at the PPP or ATM level.
A support engineer earlier on the ticket suggested something to do with noise margins to fix this, but nobody has followed up on this.
I can control some of my upload usage, but not all applications allow you to configure the upstream bandwidth limit. I've been with Zen for around a decade now, but this bizarre, frustrating and surreal experience is moving me towards jumping ship.