Softswitch - is a software switch for telephone calls.
It receives calls from originators and performs their routing to terminators or users.
When a call comes into a Softswitch, it builds a routing table and performs Hunting over a set of routes.
The routing table is built according to current system configuration and logic or Routing.
All calls are billed according to configuration.
In case if it's impossible to bill a call due to misconfiguration - it will be discarded.
Therefore, you could be sure that Billing is completely in sync with Routing and you won't loose your money.
A step-by-step instruction is available in section Configure softswitch.