Hi
Ichwan ,
If I understand correctly ,you want to enable Enterprise Voice for the meeting room system?
Based on my research, you donot achieve the room mailbox call to pstn directly, you should Setup for Exchange Room Mailboxes and Skype Room accounts,like the following link
http://lynciverse.blogspot.sg/2017/03/licensing-setup-guide-for-exchange.html
Note: Microsoft is providing this information as a convenience to you. The sites are not controlled by Microsoft. Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please make
sure that you completely understand the risk before retrieving any suggestions from the above link.
If you have on-premise environment, you could refer to the following link
https://technet.microsoft.com/en-us/library/mt691564.aspx
Best Regards,
Leon-Lu
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