What eactly does the cup Certificate do?

[Scuromano]

I'm trying to find out what exactly the cup certificate does and why nothing broke when it expired?  This is on version 10.5.2., 4 node CUCM cluster and 2 node CUPS/IM&P cluster.  It's a self signed Certificate. Does it really need to be regenerated?

[Roger Kallberg · Accepted solution]

This document outlines the important certificates in a CM and IMP system.

Cisco UC Certificates Renewal Guide