The speaker discussed the implementation of secure payments over VoIP calls in the cloud, specifically within contact centers that must follow the PCI DSS standard for credit card security. The existing problem was the use of proprietary equipment and DTMFs that sometimes failed, so the solution was a new implementation using Camellio and RTP engine for better integration with modern APIs. The architecture involved a separate environment for PCI, with a secure router and microservices for token extraction, and relied heavily on DNS for stateless deployment in different regions. The implementation passed the audit and certification process, with strengths noted in management and risk treatment. Different PCI partners were used, with SIP being the preferred protocol.