First, we need to tell Skype to trust our CallBridge. To do this we add a Trusted Application Pool. In Microsoft terminology "Pool" just means "Cluster." In this scenario our cluster is just a cluster of one CallBridge. The Identity of our cluster MUST match the common name of the certificate in use on our CallBridge. Microsoft uses this as a security check. Having the Identity in a SAN is not enough. If the common name does not match Microsoft will tear down the TCP connection. When using this command the identity should be the CallBridge FQDN. The Registrar whould be the FQDN of the Front End Pool servicing these connections. The site should be the Lync/Skype site identifier. If you are unsure of the values that should be used for registrar or site please contact your Lync/Skype administrator.