Hi all,

My setup is a little complex, so please bear with...

I use a 2860ac connected via VDSL to Aquiss (an Entanet reseller) and use the BT firmware - on Aquiss' recommendation, their staff also use these devices.
However, I noticed the connection likes to drop out every now and then. Sometimes every 2 hours, sometimes more frequent. The key point here is that the connection itself isn't dropping, but the PPPoE connection is.

How do I know this?
Well, I connected a Mikrotik (RB3011) device to it and set the 2860ac into PPPoE passthrough mode, then had the Mikrotik initiate the PPPoE connection. Initially, I had the same issue, but, with a bit of tweaking, I noticed that setting the keepalive timeout to a high value (99999 in this case) resolved the problem. The connection remained rock solid for weeks at a time. In addition, I maintain a small linux box which pings 8.8.8.8 every 2 seconds and logs any failed results. Not a single result during the time in which the Mikrotik was initiating the PPPoE connection.

Recently, however, I've had a desire to downsize my network (power bills, growing mess in spare room etc) so have decided to once again have the Draytek initiate the connection. And once more, it's dropping on a regular basis.
I cannot seem to find any 'keepalive' setting, the closest I've encountered is the ping detect feature. So I set about tweaking that. I set it to ping 8.8.8.8 with a secondary of 1.1.1.1, using default values. Connection still dropping. So I increase the time between pings - 5 minutes and the connection still drops. 20 minutes and the connection never even establishes itself.

I'm running the latest firmware (3.8.9.2_BT) and have currently switched back to having the Mikrotik do the PPPoe dial out for the time being.

I notice there's different DSL modem codes available - I'm currently using Default, but there's also AnnexA_576d17_572801 & AnnexA_574307_571801 available. I've not tried either of those as unsure to what impact it'll have.
I've also tried using the NonVector firmware, which, in addition to having 10Mbps shaved off my sync speed, didn't seem to allow any connection either.

I'd greatly appreciate any assistance with this.
Thanks.