Specs for new backend system Main Items Required:- 1 New shopping Cart System We need to develop a new shopping cart system where clients can select the services that they require when they signup, or when they upgrade or downgrade their service. 2 New Billing System We need a new billing system to enable us to show a clients account activity in real time via a secure web page. We need to move from the current system whereby the customer makes a deposit and this is slowly eradicated by service charges (which is monitored manually) to a real time billing system that integrates with a new telephone call detail records system. Customers still pay for their services in advance, but their balance will decline in real time as they receive diverted calls. This information needs to be extracted from the call detail records, which are just entries in a flat text file, like a LOG file. We need the system to fire off a warning e-mail and SMS to us and to clients when a customer hits a low water mark with their prepaid money so that they can immediately top up their account. Additionally, we need the system to fire off a warning e-mail and SMS to us and to clients when a customer hits a low water mark with their prepaid money and hasn't topped up, so that they can be temporarily cut off. The system needs to automatically recredit a customer's account when the customer's balance has been updated. 3 New Backend Payment Gatewy We need a new payment gateway implemented, that will take the output from the shopping card and process credit card payments. Full APIs for this payment gateway are available.