Hi, Marvin. It is possible to integrate asterisk with skype, but some requirements are necessary for you to do this configuration. Another question that you will need to pay attention to is the licensing of Office 365, since E3 or E1 does not have the connectivity function with the PSTN. I believe this link will support you in this implementation: https://docs.microsoft.com/en-us/skypeforbusiness/technical-diagrams
