Dynamic IP over mobile ATM

Abstract

Deploying a static IP overlay of a mobile ATM network invariably results in the poor routing of IP packets: mobile ATM isolates all aspects of mobility from the IP layer by maintaining IP adjacencies regardless of the mobile network's current location. This paper describes a novel technique based on PNNI Augmented Routing (PAR) that allows mobile routers to adapt and optimize their routing adjacencies dynamically in response to changes in the underlying physical ATM connectivity. The described solution uses characteristics of the mobile PNNI hierarchy, the appropriate scoping of PAR-distributed IP information together with simple abstractions of the underlying ATM topology to provide IP routers with sufficient information to react to such changes in an intelligent manner. The application of dynamic IP over mobile ATM is suitable for where mobile platforms reach back into a static fixed infrastructure and where completely ad hoc ATM networks are created in isolation. This paper is illustrated with a mobility scenario demonstrated by IBM at the Joint Warrior Interoperability Demonstration (JWID) 2000.