Evolving the 3GPP bearer model towards multiple IPv6 prefixes and next-hop routers

Abstract

The 3GPP architecture is not particularly IPv6 friendly when it comes to handling of multiple prefixes. The excess use of default bearers and related radio access bearers to mimic multi-addressing is not efficient, resource-wise. This paper proposes to enhance the existing Evolved Packet System bearer model to allow a bearer to have multiple IPv6 prefixes as well as multiple next-hop routers for the sake of a better network controlled traffic steering. The solution has a minimal delta to the existing 3GPP system architecture and offers excellent migration path to the new functionality. While the proposed solution advocates local traffic breakouts and use of localized network resources along with multi-addressing, it does not even attempt to change the Packet Data Network Gateway centric mobility management nature of the 3GPP architecture. The enhancements on the bearer model are based on the design principle that IPv6 prefixes meant for localized network access do not need mobility, thus reducing the amount of system level signaling during mobility events. The solution works only for IPv6, while the existing IPv4 functionality is kept intact. This paper describes in detail the new bearer model, including an extensive discussion of how IPv6 is supposed to be implemented on top of it, and analyzes the impact of required changes and the backward compatibility with the existing Evolved Packet System.