The subject matter described herein includes methods, systems and computer readable media for using a Diameter routing agent (DRA) to obtain mappings between mobile subscriber identification information and dynamically assigned Internet protocol (IP) addresses and for making the mappings accessible to applications. One exemplary method includes, at a DRA, receiving a Diameter message containing a dynamically assigned IP address and mobile subscriber identification information. The method further includes routing the received Diameter signaling message. The method further includes copying, by the DRA, the IP address and the mobile subscriber identifier from the message. The method further includes making a mapping between the dynamically assigned IP address and the subscriber identification information accessible to applications.