Forgive me I do not fully understand the black art of certificates!

We have a DAG with 6 Exchange 2013 CU7 servers.  Each server has the same internal Certificate Authority issued certificate installed for Exchange and was setup by consultants.

We are now looking to configure EXUM and I would like to know if we should be looking at using the same certificate for UM or if we should be looking at getting a new certificate for UM?

If we should be using the existing certificate would it need to be installed in Lync?

If a new certificate is recommended what is guidelines for required certificate?

I am going round in circles looking for definitive instructions without much luck.  A steer in the right direction to the best document to follow for setting up UM would be much appreciated.

The current certificate details are as follows

Name :- Exchange Internal Cert

Issuer  :- Is the internal CA

Subject :- CN=ExchangeCert

Subject Alternative Names :- contains ExchangeCert, 6 servers FQDN, 6 Servers hostnames, the FQDN for each of the Exchange services E.g. eac,owa.

• Moved by Winnie LiangMicrosoft contingent staff, Moderator 4 hours 25 minutes ago