A 16 U license actually allows 22 phone slots (16 IP Phones + 4 FXS + 2 Teleworker). Check you configuration and make sure that you don't have some ephones just lingering there. You could also disable SCCP registration of your FXS ports to enable more slots. You do this in CCA 2.0 by declaring these ports as "Fax", not "User".
Marcos Hernandez Technical Marketing Engineer Cisco Systems, Inc.
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