At the moment, as you've probably guessed, the international nature of NGNs such as Skype mean that are largely unregulated.
According to Ofcom, over time it expects NGNs to offer consumers a wider choice of new products and services, as well as better value for money.
"However to ensure these benefits are delivered, providers need to agree the technical and commercial arrangements for connecting to each other's networks," said the regulator.
And that's the crucial issue - interconnection.
At the moment, interconnecting between different VOIP networks is a bit of a nightmare - assuming you can do it all, of course. And you can usually forget about your VOIP calls being encrypted on an end to end basis, as well.
Ofcom has created a new industry body, NGN UK, which will led by Peter Black, a well-known Ofcom luminary.
Surprisingly, a number of carriers have already committed to NGN UK, including BT, Cable & Wireless, Easynet, Kingston Communications, NTL, Thus, Vodafone and Wanadoo.
Quite an eclectic mix there - but no pure VOIP carriers yet. We can but live in hope...