A2Billing lends itself to voice service providers who wish to provide DID (telephone numbers to their customers. DID can be forwarded to an IP-PBX or VoIP phone, as well as being redirected to PSTN destinations.
A-Leg billing is supported meaning that the owner of the DID can be charged with a per minute rate for their DID as well as monthly rental charges. Conversely, a customer can be credited for calls via premium rate DID as well.
B-leg charging for PSTN destinations is also supported, as are failover destinations if the VoIP device is offline.