Below is a diagram showing the calls and data-flow between the entities in A2Billing.
A2Billing can provide a number of services to the end customers including, but not limited to, Wholesale, business and residential VoIP origination and termination, calling card and call-back services, and special applications requiring telephony and billing.
Termination and Origination
A2Billing supports origination and termination using a variety of technologies such as VoIP, PSTN (PRI, BRI and analogue circuits) and GSM gateways.
A2Billing has a number of payment methods including online payment processors including Paypal, as well as manual payment and top-ups using vouchers via an IVR or the customer's portal with full accounting and reporting.
Sales and Marketing
A2Billing supports commission agents allowing online signup and affiliate marketing, as well automated signup via a simple telephone call providing easy customer acquisition.
The architecture of A2Billing consists of a database server, Asterisk telephony server and a web-server for administration, agent, customer and online sign-up. Usually these servers are hosted on the same physical hardware, but can be distributed across multiple servers to increase the capacity. A SIP proxy can be added to load balance calls across multiple Asterisk servers and assist with NAT traversal.