I have a similar problem with a Grandstream GPX1200 losing connection to Voiptalk when connected through a Draytek 2820Vn or 2830Vn. The phone will change to 'Not registered' and no amount of phone restarts will do anything. Rebooting the router cures the problem.

I'm now trying the phone through a Billion 7800N router and so far have encountered no connectivity problems - it would suggest the problem is with the Drayteks.

Its early days for me, but I have re configured two client networks and the phones now use a dedicated router (Thomson and Netgear) for their dedicated DSL line. No NR messages for me so far. Thats Snoms and Polycoms.

I get this too using a Cisco SPA2102 to get an additional couple of lines.

90% of the time it's fine and then one day it'll stop registered either or both of the handsets on the Cisco and I have to reboot the 2820 to get it back and working again.

Hopefully this will get sorted sometime soon!

2 months and no further mysterious NR`s requiring router reboots. The answer is not to use the 2820 for VOIP phones. Anyone tried the Billion 7800 (looking for the dual WAN capability specifically).

I've been using the Billion 7800N for a couple of months and had no SIP problems at all. I prefer the Drayteks for all their other features but the SIP problems make them a no-no for me just now.

Raise a support call. They have a firmware in beta that's fixed all my SIP problems with the 2820 itself and also with my third-party SIP adaptor that kept losing registration requiring a reboot of the 2820.

Mine's been running for over a week on this firmware now with no issues whatsoever and no reboots required.