After buying a CA sign certificate from Geotrust i got this in my Event viewer:

Remote principal name is not configured in trusted server list.

The subject name sip.XXX.com of the certificate assigned to process AVMCUSvc(1788) was not found in the trusted server list.
Certificate serial number: OU=Equifax Secure Certificate Authority, O=Equifax, C=US
Certificate issuer name: 0DA2A3.
Cause: Incorrect setup of the pool. Should never happen.
Resolution:
Verify that the Subject Name of the certificate presented by the remote peer is configured in the trusted server list.

For more information, see Help and Support Center at

I fix this problem by typing:

c:
cd \
cd “C:\Program Files\Microsoft Office Communications Server 2007 R2\ResKit”
cscript OCSTrustEntry.vbs /action:add /FQDN:sip.XXXX.com /type:TrustedServer

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