On 30 March 2016 at 12:46, David Derrick <[email protected]> wrote: > I'm a bit stumped here, wondering if anyone else has seen this or is using > the same kit with no issues. Even better if you happen to be one of our > resellers. > > Zyxel SBG3300-N router > 21CN lines (ADSL or FTTC with or without OR modem) but not all lines > Juniper MX480 LNS > > Symptoms are high packet loss and frequent disconnects but only on some > lines. > Swap the Zyxel for a Cisco, problem goes away. > Take the Zyxel to a different line, problem goes away. (This may be true > with two lines into the same building via the same exchange.) > Different Zyxel (same model) from a working line to the problem line, > problem persists. > Terminate the user on one of our Cisco LNSs but same router and line, > problem goes away. > > This problem first appeared at the start of the year, went away for a while, > and has now returned. Most of this customer's lines are in Scotland. Problem > exists with current and previous versions of the Zyxel firmware. > > Does anyone have any ideas? We're trying to get BT to look for commonalities > between affected lines but haven't had an answer yet.
On 31 March 2016 at 11:02, David Derrick <[email protected]> wrote: > I probably wasn't clear enough that the copper lines have been checked and > are fine. That was one of the first things investigated and we've had > Openreach guys out to look at several of them. The fact that this problem > exists both with the OR modem and with the Zyxel's built in modem suggests > to me it isn't line related but there is some sort of strange interaction > from Zyxel->DSLAM->BT->Entanet->customer. It sounds like something at the PPP layer (or above) since it only happens with certain modem/LNS combinations. Strange you should say it's in Scotland, as per David's comments are you running MLPPP? I've had some issues with MLPPP over 21CN of late and the only comonality I've found so far is that the affected lines are to the same handful of BT BRAS nodes in Scotland. Have you been able to run a packet capture near your LNS and and analyse then when there are issues? Cheers, James.
