A transparent session migration and transparent fail-over protocol for PPPoE server cluster

Recently, many LAN sockets service are provided in various areas. We presented the implementation and its evaluation of the authorized LAN socket system with PPPoE in previous works. Since most PCs have 100Mbps Ethernet port, one PPPoE server can only serve small number of clients because ordinary server has at most 1Gbps Ethernet port. To cope with this limitation, we adopt the clustering technology for the PPPoE server, but PPPoE protocol lacks the features for a reliable cluster such as dynamic load balancing and transparent fail-over. We propose a PPPoE client migration scheme that works without modifying the client PPPoE module. We also implemented a sample server to show the scheme is capable of constructing PPPoE cluster with transparent session migration and transparent fail-over. The key issues are using "per session MAC address" for each client session and sharing the client informations among all server components. Our experimental system shows only one second stall during migration, this is enough to the Internet applications such as Web browser and streaming real-video.