Abstract: The present invention relates to a communication node and method for connecting and maintaining a call between a caller device and a callee device. The communication node comprises a session controller module and a plurality of internal SIP UA (Session Initiation Protocol User Agent) servers. The session controller module is adapted to remain in communication with the caller device and the callee device through a whole duration of the call. The plurality of internal SIP UA servers is adapted to communicate with the session controller module by open protocol.