An architecture and implementation toward multiprotocol mobility

The challenge is to design a set of protocols that provide seamless and robust network connectivity to mobile users for a variety of existing network protocol suites. An important additional constraint is that the design should not require any changes to the existing stationary infrastructure and it should interoperate with the existing protocol stacks at the stationary hosts. We propose a mobile data link (MDL) architecture that endeavors to meet this design challenge. The architecture hides the topological effects of mobility at the data link layer, thus making topology changes due to mobility transparent at layers above the data link. This provides a single mechanism to support a variety of distributed applications that use different protocol stacks without requiring changes to the implementations of the stacks. Further, the-solution provides the enhanced degree of mobility provided by prior network layer solutions. The novel features of the proposed solution are the use of the network layer infrastructure for carrying data link traffic, the ability to dynamically maintain a data link overlay over a common network layer infrastructure, and efficient handling of the broadcast traffic. We have developed an MDL architecture that allows data link networks (formed by the interconnection of LAN segments by bridges) to be dynamic, thereby supporting mobile hosts, eliminating the need for manual configuration. Moreover, our scheme efficiently handles broadcasts and multicasts