XMLPay Specification

A wide variety of payment types is available for conducting commerce over the Internet, including debit and credit cards and automated clearinghouse (ACH) payments. The XMLPay specification, created by VeriSign and Ariba, addresses sending payment requests and responses through financial networks, using XML. The specification is open and can be used in both business-to-business (B2B) and business-to-consumer (B2C) Web services.

XMLPay can communicate requests for payments through intermediary payment gateways, such as VeriSign (Figure 16.2). A Web service can communicate requests for payment to the XMLPay gateway, which in turn switches the request to the appropriate financial institution and returns the result to the Web service.

Figure 16.2: XMLPay flow

In a B2C scenario, the selling Web service forwards the buyer's payment information to a payment processor. The selling Web service formats an XMLPay request and sends it directly to an XMLPay-compliant payment processor or indirectly via an XMLPay payment gateway. In a B2B scenario, the seller may not initiate payment requests and may use a trading exchange. The trading exchange, in turn, uses XMLPay to communicate purchasing information to the payment gateway. In this manner, payment can be linked to other Web services, such as purchase orders and advance shipping notice delivery.

Services of high importance to an organization are the ones most likely to have charges associated with them. Services such as the weather or stock quotes are most likely to be free. With the advent of a paid Web services model, organizations will also need to consider quality of service guarantees.