An apparatus for providing communication routing information for a subscriber in a mobile communications network, the subscriber being registered with at least one communication delivery network node, comprising: receiver for receiving a request for communication routing information for a subscriber from a network entity, wherein the communication routing information comprises the network routing address of the communication delivery network nodes which the subscriber is registered with; means for determining the capabilities of the network entity, the capabilities comprising the number of communication delivery network node routing addresses manageable by the network entity; identifier for identifying the at least one communication delivery network node the subscriber is registered with; comparator for comparing the number of communication delivery network node routing addresses manageable by the network entity with the number of communication delivery network nodes with which the subscriber is registered; and transmitter for delivering communication delivery network node routing information for the subscriber to the network entity wherein the number of communication delivery network node routing addresses provided to the network entity does not exceed the routing capabilities of the network entity.