Concerns regarding the scalability of the inter-domain routing have encouraged researchers to start elaborating a more robust Internet architecture. While consensus on the exact form of the solution is yet to be found, the need for a semantic decoupling of a node’s location and identity is generally accepted as the only way forward. One of the most successful proposals to follow this guideline is LISP (Loc/ID Separation Protocol). Design wise, its aim is to insulate the Internet’s core routing state from the dynamics of edge networks. However, this requires the introduction of a mapping system, a distributed database, that should provide the binding of the two resulting namespaces. In order to avoid frequent lookups and not to penalize the speed of packet forwarding, map-caches that store temporal bindings are provisioned in routers. In this paper, we rely on the working-set theory to build a model that accurately predicts a map-cache’s performance for traffic with time translation invariance of the working-set size. We validate our model empirically using four different packet traces collected in two different campus networks.