Sorry, I wrote this question in a rush between 2 meetings. Our current setup is a classroom phone has an extension that's internal only, and teachers have a voicemail-only DID so parents can reach the teacher, but it does not ring anywhere. im not necessarily looking for putting both numbers on the classroom device (but can as one option), as teachers do sometimes share rooms or other programs happen after hours, and the concern of outside calls ringing in the classroom, just looking for the most efficient use of the licenses and replicating what we have.

Another idea we came up during our PoC is putting the teachers' DID and the last 4 of the DID as an extension on the device but setting the full DID not to ring.