Instead of having the router default automatically to VOIP and having to dial #0 to select PSTN it would be great if a selection box could enable PSTN by default and de selecting it would revert to VOIP as default as many of us (UK at least) get free BT PSTN landline calls

Or time based dial plans .. so when the free evening and weekend calls are available on POTS you can schedule it to use that - and VOIP at other times (perhaps).

I second this for the 2820VN

Defaulting to VOIP means that the SMS features of my phone are unavailable as they require a PSTN line.

Also, Caller ID does not work for PSTN calls when VOIP is the default. If I turn my router off (enabling the fallback to PSTN) then Caller ID comes through fine.

Caller ID on VOIP calls works no problem.

This is my biggest gripe with the router which otherwise I can't fault.