The CUCM Branch Exchange is responsible for registration of IP phones and videoconferencing units, numbering plan management, call routing, call permissions and many other functionalities. It is a virtualized application with a high emphasis on capacity scalability, designed for deployment by customers of all sizes. Support for SW clients, high quality of transmitted voice and video, emphasis on security, use of standardized signaling protocols. These are all features that CUCM offers after basic installation and configuration. Open APIs are used to integrate with other IT systems, so the entire system can be tuned to the exact needs of individual customers.