I came across this recently when I had to conduct a bit of a deep dive into how Lync conferences behave when they effectively reach “end of life”. In the first instance, I managed to find this about conference expiration in Office 365:
• For a one-time scheduled meeting, the expiry time is the scheduled end time plus 14 days.
• For a recurring scheduled meeting with an end date, the expiry time is the scheduled end time of the last meeting occurrence plus 14 days.
• For an ad hoc IM or A/V conference, the expiry time is 8 hours.
• For a recurring scheduled meeting without a specified end date, the expiry time is 6 months after the last meeting activation.
To clarify, meeting activation is whenever a conference is accessed by a participant.
These settings apply to Lync on-premises also, but I wanted to know if they could be modified. I knew I’d seen something mentioned about modifying when conferences end, and Brian Ricks reminded me of Set-CsUserServicesConfiguration. With this cmdlet, we can set a parameter -DeactivationGracePeriod that allows us to set the maximum amount of time that a meeting can remain active. However, this was only half of the story.
Deactivation and expiration are related, but different.
Deactivation is when the server will forcefully shut down a meeting. It’s like a server-driven version of the exit-and-end-meeting presenter command. However, you can immediately reactivate a deactivated meeting. This is just a brake on runaway meetings, so if someone locks their workstation and goes on vacation while signed into a meeting the meeting will eventually end. It’s meant to be an “infinity” value. You set it just higher than you expect a real meeting to last.
Expiration is when the server deletes the meeting, its contents, and coordinates (i.e. the link won’t work anymore). Expiration can’t happen while a meeting is activated, and there are grace periods based on the meeting type and scheduled end date. The grace periods are to give time to download meeting data (like uploaded handouts or whiteboards) before it’s deleted.
So, conference deactivation is when Lync will end an active meeting so it doesn’t sit there and take up server resources unnecessarily. It’s controlled using the cmdlet I mentioned above (Set-CsUserServicesConfiguration). Conference expiration however is hard-coded behaviour based on the type of conference that’s been initiated and means the absolute end of a meeting. This means the meeting URL and conference ID cease to work and all meeting content is deleted.
Interesting stuff to know. Credit to CJ Vermette from Microsoft for explaining this and clarifying how the two behaviours are different.
