Tools drop down: Dial-in Conferencing Settings= no dialog. Response Group Settings = 404 error
Response Group Settings redirects to https://webpooldm21a02.infra.lync.com/RgsClients/Tab.aspx which is 404.
Steven S commented
I'll add to this that Response Groups are a critical feature. Most organizations have a support # that multiple employees are responsible for answering and need to be able to have calls distributed to whoever is available.