SAP HCI is created as Integration Platform-as-a-Services (PAAS) which helps you to combine multiple independent devices/purposes for a business method. HCI can perform Cloud to Cloud, Cloud to On-premise, On-premise to On-premise and Hybrid design. HCI features Adapters (Connectivity alternatives) for instance: Cleaning soap Adapter, IDoc, HTTP, Mail, SFTP,Ariba, oData. https://s4-hana-cloud-faq47024.blogproducer.com/34533894/hana-cloud-integration