A communication network unit having a memory for storing, for each communication terminal of a plurality of first communication terminals which are each associated with a same user identification, information about communication capabilities of the respective communication terminals a determining unit for determining which communication capabilities can be used for communicating with the user identified by the user identification based on the information about the communication capabilities of the first communication terminals, and a signaling unit for signaling to a second communication terminal which communication capabilities can be used for communicating with the user identified by the user identification.