UCCX Enhanced does not include the Advanced IVR license and therefore, IVR ports are not licensed. The install will be limited to the platform limits. On a 7845 this is up to 300 ports depending on design and features implemented.
Please reference the SRND for additional details.
Cisco Unified Contact Center Express 6.0 Solution Reference Network Design (SRND): http://cisco.com/en/US/docs/voice_ip_comm/cust_contact/contact_center/crs/express_6_0/design/guide/crs60srnd.pdf
Also, the Configuration and Ordering Tool is required when designing a UCCX deployment as part of the A2Q process. This may require a partner-level CCO account to access: http://www.cisco.com/en/US/prod/collateral/voicesw/custcosw/ps5693/ps1846/CRS_Config_Order_Tool_for_CCE_6.xls
