PSTN/PBX setup, Mac OS X

Copper Contributor


Hello --


We have team of five people, with a outside PBX/SIP (3cx). We have just signed up our entire team with Office 365, all users are on a T5 plan, with active Domestic&International calling plans. We are trying to connect our SIP with Skype Business' PSTN/PBX service. 


Within the Skype business admin center, every user has "PSTN connectivity: online", however, under the tab "on premises PSTN", it states "No on premises PSTN information is available". 


We have not been able to find out how to turn the PSTN on or manage the PBX Office 365 services. -- We are a Mac's only and read several reports that one needs to set this up via Microsoft Shell / Skype for Business Online cmdlets; we have tried this attempt, but our coding skill are inadequate, and it doesn't seem to be working well on Mac. 


Is there a more traditional way of approaching and fixing this matter? - Any help with this matter are greatly appreciated. 


Thank you. 



2 Replies

The "on premises PSTN" tab you are referring to relates to hybrid voice configuration. A hybrid voice scenario is where you have your users homed in the Office 365 cloud using Microsoft Phone System (Cloud PBX) functionality, but their PSTN connectivity actually breaks out from your office rather than through Microsoft's Calling Plans. To set up hybrid voice you need an existing on-premises Skype for Business Server deployment, or a Cloud Connect Edition solution. Either of these two components will then be able to proxy calls between the local PSTN connectivity and the Skype for Business Online users.


That is the only scenario where that tab is relevant - it's not for directly connecting a third party PBX solution such as 3CX.


You can read more about providing on-premises PSTN connectivity for Microsoft Phone System here;


Kind regards


The best option for an organization of your size would be to port your phone numbers into Microsoft Phone System and just use the Microsoft Calling plans and eliminate the on-premises 3CX PBX.