User nodes are homed to network nodes in an IMS network or other communication system by determining a function hierarchy for functions provided by the network nodes. Starting with a function at an initial level of the function hierarchy, a predetermined criterion such as throughput-weighted distance is applied to assign a given user node to a particular network node providing that function. The homing process then proceeds through one or more additional levels of the function hierarchy to assign the given user node to at least one additional network node providing at least one other function identified in the additional level(s) of the function hierarchy. These operations are repeated for one or more additional user nodes until each of the user nodes is homed to one or more of the network nodes providing all of its required functions.