standard function
SAP help Computer Telephony Integration
drawback
Only client-side Integration is supported so you must have a client-side application to communicate via the built in adapter.
Agents using the CTI solution must have this client-side application running on their desktop.
(1) Inbound calls are achieved using a parameterized URL that your client-side application passes to the SAP Hybris Cloud for Customer CTI Client Adapter. This allows the call attached data to display in the Live Activity pane in the solution.
(2) Outbound calls are achieved by using a DLL which passes the dial out phone number from SAP Hybris Cloud for Customer to your CTI solution and in which you have included the necessary dial-out logic.
enable inbound call：
https://help.sap.com/viewer/cea15f900ca04c4faa35d3044577fe27/1708/en-US/2534475c2bb544ffbbde4fbfe60da58f.html