Using VoIP in various countries

Question posted by Stuart White, on behalf of UKTI South East in PO15

I am trying to find out the legal restrictions in using VoIP in the below countries, any guidance would be most appreciated for a starting point

Australia
Brunei
China
India
Indonesia
Malaysia
New Zealand
Singapore

Am also seeking a list of countries that a company specialising in VoIP could provide to.

Appreciate any help

Stuart