IPswen: A Long Term Evolution Approach for the IPv4 Internet Architecture

After decades of IPv6 development., it is clear that the “legacy”” IPv4 protocol stack and the TCP/IPv4 architecture will coexist with IPv6 in the foreseeable future, even if IPv6 deployment or availability rate is reaching 100%. This paper presents a practical approach for the long term coexistence and evolution of the TCP/IPv4 architecture. The core idea is to adopt a variable length addressing and routing scheme (IPswen) to preserve the entire IPv4 stack with bidirectional interworking. Under strict design constraints., IPswen is an incrementally deployable and binary backwards compatible (evolutionary) solution to upgrade existing IPv4 networks, with a sufficiently large address space for long term evolution, which is a multilevel L3 address space that consists of 8 subspaces of address lengths ranging from 4 to 11 bytes. Results of a single-stack Linux implementation demonstrate its usability and binary code compatibility with TCP/IPv4 and existing socket API applications. We argue that IPv4 still possesses a potential for substantial extension after adopting CIDR and NAT44., and IPswen might be in a much more promising direction for the continued evolution of the TCP/IPv4 architecture than the conventional wisdom that we need to transit everything of the Internet from IPv4 to IPv6.