Because our BX2000 is mission critical like yours I do now have a second one (partly purchased, unfruitfully, in the hope that its POTS interface would work enough, and better than the other one, to be useable).

I will load the rst version of the 3.8.8.4 firmware when I get a second, then load in the settings files from our live unit and see what happens.

Just as an aside, if this provides any extra insight into troubleshooting, we use WAN2 for VOIP via a Draytek Vigor 120V2 ADSL2+ modem.

WAN1 is used for a fast FTTC fibre (80/20) connection for general internet access and not used for VOIP.

I know that it is an eternity since my last post, but it is difficult to find the time for experimentation!

I have just updated my second BX2000 with the current latest version of the firmware (3.9.0), and then loaded the config file from our live device (which is still running 3.8.1.8 ).

The result? Outgoing VOIP works fine via our SIP trunk (which does not use registration), but incoming calls fail with three beeps. Switching back to the old router works fine aagain.

One change that I have noticed with the new firmware version is the addition of ALG in the NAT section of the UI, although no explanation in the latest manual of what that does. Obviously it may have some bearing because there is a checkbox for SIP and RTSP, but whether it is enabled or not the same problem occurs.

Incidentally I had a real struggle to get the new version of the firmware into the BX2000, and eventually had to use the TFTP approach rather than loading it via the UI. In every other respect than incoming SIP calls the router seems to work fine.

So I am back to 3.8.1.8 again and reluctant to even try going to a newer firmware version again.

Hi.

Just to say that even the latest firmware - 3.9.1 - does not fix the problem.

I've got a support ticket open about the issue. Strangely, Draytek say they are not aware of this ongoing problem.

I wonder how many BX2000s they have out there - maybe yours and mine are the only ones!

Just got off the pohone with Draytek support, and apparently, at least for me, this is a known problem with unauthenticated SIP trunks (where the BX2000 does not register with the SIP provider).

They are "working on it" but there is no acknowledgment of the problem in the Release Notes. I will just have to stay with 3.8.1.8 until it is fixed.

Hopefully when it is finally fixed they will mention that in the Release Notes!!