In the previous article we upgraded our directory synchronization server from the older DirSync to the latest version of AAD Connect to prepare our Skype for Business hybrid environment for Office 365 E5 Cloud PBX with on-premise PSTN Connectivity. In this article, we will configure our Skype for Business on-prem environment with a simulated PSTN connectivity using an Asterisk IP-PBX. We will create the necessary PSTN Gateway and Trunk from the Skype for Business side, and configure the corresponding SIP trunks and inbound/outbound routes on the Asterisk side. Then we will register a Polycom VVX600 and Polycom Trio8800 using accounts homed on the on-premise Skype for Business and make sure they are able to call extensions on the Asterisk IP-PBX. Once this is completed, we will move those accounts to Office365 E5 and test the voice functionality again to confirm that on-premise PSTN connectivity is working. Below is the diagram of the initial setup before moving accounts to Office365: |