Evaluation of Mobile Ethernet switch on network processor

We have proposed Mobile Ethernet (Kuroda, M. et al., IEEE WCNC, 2004) to provide a mobility management mechanism on a widely deployed Ethernet network; it accommodates heterogeneous radio access systems, including 3G. Mobile Ethernet has features to realize fast handover across heterogeneous radio access systems using a mobility management mechanism at layer 2, and to achieve good scalability by partitioning the network in segments to suppress multicast messages. A network processor is a candidate hardware platform for the layer 2 switch which we call Mobile Ethernet switch. We discuss implementation of the switch using the Motorola network processor C-5e/spl trade/ while verifying its feasibility as a Mobile Ethernet switch. We evaluate the switch by the frame forwarding overhead and the number of MAC entries it can support compared to a typical layer 2 switch. We confirm that the Mobile Ethernet switch can forward MAC frames at the line speed of the Gigabit Ethernet by using parallel pipelines in aggregated channel processors in the network processor, though MAC address swapping for interface switching is added to a typical layer 2 switch. The overhead for the additional function is negligible because of the performance limitation of the physical interface in the case of Gigabit Ethernet. We also confirm that the switch can forward frames at gigabit speed by using a hash of more than 14 bits as lookup key for MAC address search, when there are up to 512k MAC entries. This performance and capacity are enough for our Mobile Ethernet assumptions.