Search:

Yes. It is amazing. However, you can get more advanced system these days, which are more reliable and faster.
______________
telecom billing

You can look for the billing software available in the market. They are simple, reliable and efficient. Get the trial version if you want.
______________
telecom billing

I do not have any favorite system as such but i am using telecom billing software as i am managing a call centre.
_______________________

I think looking for the ASP based application would consume a lot on the head. Rather it would be better suited to have a complete software package that is compatible with all the utilities.