My 2110Vn seems fine with VOIP calls, but PSTN calls have low volume and high background noise making such calls almost unusable. The same phone(s) into the BT line direct through the same house wiring, microfilter etc. are OK.

Anyone else having this sort of problem, either with the 2110 or another Vigor V?

Hi there...I noticed a newish version of firmware (3.3.1.2) was available around October time. Have you tried that as its supposed to deal with loop through issues. I have just ordered a 2110vn to replace a 2900vg which has done sterling voip service, but has a habit of dropping SIP connections a couple of times a day.

Release notes for 3.3.1.2 can be found here...
http://www.draytek.co.uk/support/download/readme_v2110.txt