Hi

Shame, but maybe a sensible solution. A wee while back I was thinking of getting a more current Draytek (so I could use tag based VLAN) but I don't need the wireless n part (I've a separate Cisco WAP). Of course, you only get the VoIP in the wireless n version, so it would be cheaper to get a base model 2830 and a Cisco SPA112 (which I think is the replacement for the PAP2T). I'm yet not sure I'll go down that route (VLAN requirement shelved for now), so I'd like to see this fixed and it just isn't cool to have such a major bug (in what was a top router) and to not fix it sooner than this; I'll contact support tomorrow and ask them what's happening.

Bri

problem I found when debugging is how to replicate the issue with them.

Same problem here on 3.3.7.3_232201.

It has taken me a while to eliminate various things as it seemed like phone hardware at first but I have 2 VOIP providers and 3 phone handsets to try so narrowed it down to the 2820 eventually.

The "stuck" DTMF tone seems to match the number 4 key frequencies. The other person cannot hear it but it makes it impossible to carry on the call. It's a major problem and very frustrating.

FWIW I had the same issue when I had a 2820. It appeared after a firmware upgrade, but stayed after a downgrade as I recall. I have a 2830 now which does not have the problem.

Draytek recommended I send the unit back for repair but instead I changed my 2820 for another of the same model and the problem continued.

After experimentation today I discovered the issue can be reproduced by sending a brief DTMF from the other caller. This triggered the DTMF tone to be relayed and "stick" on the 2820. The fix seems to be to change Phone Settings > Advanced (button in bottom right) > DTMF Mode from OutBand to InBand. I am not sure if there are any other implications for changing this setting but it seems to work so far

Curious to know if others can reproduce in the same way and what provider they use. I am using Voipfone.