I thought I would try out the VDSL modem part of my Vigor 2860ac by replacing the existing BT supplied Modem that was installed with my FTTC installation 2 years ago. I have followed the setup instructions from the Draytek UK support site, and have successfully got logged into my Zen Internet Fibre broadband account. The modem connection details are:

VDSL2 Information (VDSL2 Firmware Version: 576D17_A/B/C with Vectoring support )

Profile State UP Speed Down Speed SNR Upstream SNR Downstream
17A SHOWTIME 19999 (Kbps) 79997 (Kbps) 15 (dB) 6 (dB)

So far the system uptime is 18 hours.
However, the trouble is the PPPoE connection to Zen keeps resetting every 1-2 hours (not sure whether the modem is resetting / resynching as well but I suspect not, since BT have not so far at least, detected the line as unstable and the modem is still connecting at the highest possible speed setting.

Any idea what is causing this? I would be grateful for help to improve the stability of the Zen PPPoE connection. With the BT Modem connected to the WAN2 socket on the Vigor 2860ac I used to remain connected solidly to Zen for weeks at a time.

Thanks
NigelS

You don't say which router firmware version you are using but I have a 2860n+ on firmware 3.8.2.2 (VT3) which is pretty stable on my Zen connection - currently up for 167 hours after I did a manual re-start whilst fiddling with settings (much slower than yours though as I'm quite a distance from the cabinet).

I think others here have reported similar problems with the 2860ac but why it should be any different to the n+, if indeed it is, I have no idea. Sorry.

Do you know if you are on an ECI or a Huawei cabinet? That might have some bearing.

Hi there

Thanks for responding. I have the f/w 3.8.2.2_VT3 same as you, and elected to install the recommended Vector3 modem code (full details shown in previous post).

I think the BT cabinet is ECI and the previously used BT Openreach modem was labelled ECI Telecom Ltd (B-Focus V-2Fub/r RevB; dated Feb 2013).

NigelS

Whether or not this http://www.ispreview.co.uk/index.php/2016/04/bt-briefly-start-stop-g-inp-roll-eci-fibre-broadband-cabinets.html has anything to do with it I can't say. Might be worth dropping a line to Draytek support to see if they have a view.

In the meantime I'd be tempted to go back to your OR modem, as in my experience the DLM system seems to be keen on dropping your line speed but very reluctant to put it back up again.

Try the Vector 2 modem code to see if that is any more stable?

I think that if the PPPoE connection is dropping out, it's worth determining whether that's a modem or PPP issue - check the router's syslog output , the WAN information specifically because it would show that.
http://www.draytek.co.uk/support/guides/kb-vigor-syslog - the USB method should work well

interestingly, without doing anything the modem now has been up for 55 hours and counting, so maybe the issue was with Zen or BT instead?