Has anyone attempted to integrate Verotel as a Payment Provider for Merchello? I think it would be similar to PayPal but I am struggling to get my head around it. It would need to generate a signature from some of the invoice, payment fields and pass them to Verotel as a query string with the signature for verification, the customer fills in the Credit Card details at the Verotel end and then Verotel calls a Post back URL which checks a signature and if OK the processes the successful transaction, Verotel also handles subscriptions which I need to implement as well. Any pointers would be gratefully received. Thanks