IPv6 Transition for the Other Billions

The transition to IPv6 has been an inevitable trend because there are still more than half of the world's population without the Internet access but the global IPv4 address space has been exhausted. Meanwhile, IPv6 users and emerging IPv6 services still need public IPv4 addresses to communicate with the global IPv4 users and resources, making it important for providers to share scarce global IPv4 addresses effectively. Existing IPv6 transition mechanisms have their own address sharing solutions, but none of them is good enough to be deployed in large-scale networks. In this paper, we propose a novel hybrid address sharing scheme, denoted by HAS, which can be both scalable and agile enough in large-scale deployments, and can help the other billion users access the Internet in a graceful manner. Moreover, the HAS scheme can be deployed in different phases of the IPv6 transition process and can provide a transparent, smooth, self-benefiting IPv6 transition strategy. We implemented the HAS scheme and have deployed it in the Tsinghua University Campus Network (TUNET) to provide Internet access for thousands of campus users. The real traffic data show that the HAS scheme has a good performance in actual deployments.