Unfortunately, currently how shared calling is implemented, does not fit our needs. I was hoping - when looking through that, for something else.
The idea sounds great, but to me - or better to say to my company's needs, it was poorly implemented. I do not understand why there is a need for an AutoAttendant to get this working. With the AutoAttendant in between, i have to direct the call to <somewhere> or play a greeting to the caller and then enable voice input. But - where to direct the call to, or in case of voice input, what if i do not know to whom i want/need to talk (in our specific use case, it would be shift leaders in the manufacturing plant or warehouse workers... i want to call that "department", and i do not care who currently is on shift in that department or area...). I do not see this currently as an advantage over Call Queues, which basically (can) do the very same thing with an upblown functionality. To my knowledge, you can assign an account to a call queue without own phone number in a Direct Routing scenario, but not on a CallingPlan or OperatorConnect - maybe that was the intent here...
I fully understand that the underlying resource account would require an Application to call to. But for shared calling, the AA is not the fit. the better fit would then be Call Queues, but that functionality was there before. I did wish for a "call queue light" as 3rd application, without the full blown functionality of CQ's... just simply assign users to that 3rd native app and be done with it. There still does not seem to be a good solution to bring multiple users/accounts to one shared phone number for in and outbound calls. (multiple accounts using one number as well as multiple numbers for one account - that was what i have wished for...)
Based on that blog entry:
https://easy365.io/microsoft-teams-shared-calling-faq-6b3a6be69bcd
it states that the difference between CQ and Shared calling is that with the Shared Calling AA you "explicitly request the person they are trying to reach". But that also was available before on AA, but the outbound option was missing (which could have been covered then when assigning those accounts to a CQ and give them the caller ID...)
I also have tried to set up that Shared calling for outbound calls only, but for whatever reason, i can not bring my test account that i used and assigned that shared calling policy to call out via that shared line number/resource account. I thought i followed the process, but something is wrong here - create resource account with correct pstn usage/voiceroutingpolicy, assign the resource an emergency callback number, assign sharedcallingpolicy and "empty" voiceroutingpolicy to user - which then at least should do outbound calls.)