[hrgajek]

Hello,

maybe there some children-disease ("Kinderkrankheiten") problems, but the main principle is allways the same.

You need a small (GSM)-SIM-Provider who needs more traffic in his networks and gives you affordable rates. This Provider could not have the necessary good interconnections like a T1 Carrier like BT, DT, FT etc.

You need a numbering provider in let's say the UK, there are a lot of it, as Ofcom gives numbering codes to all companies who whant numbers.Then you need interconnect regime (routing, tariffs etc.) to those "unknown" numbers.
If the mainstream providers do not know the exat destination or the tariff is not convenient... they don't connect or route to Nirvana.

Remember the "good old days" of United Mobile. They lived of very high interconnection tariffs to +421 663 ("Premium Rate"). But one day these tariffs were reduced... The rest is history.