PhD viva success: Ryo Yanagida

Congratulations Ryo on passing your Viva!

Mobility Multihoming Duality for the Internet Protocol

In the current Internet, mobile devices with multiple connectivity are becoming increasingly common; however, the Internet protocol itself has not evolved accordingly. Instead, add-on mechanisms have emerged, but they do not integrate well. Currently, the user suffers from disruption to communication on the end-host as the physical network connectivity changes. This is because the IP address changes when the point of attachment changes, breaking the transport layer end-to-end state. Furthermore, while a device can be connected to multiple networks simultaneously, the use of IP addresses prevents end-hosts from leveraging multiple network interfaces — a feature known as host multihoming, which can potentially improve the throughput or reliability. While solutions exist separately for mobility and multihoming, it is not possible to use them as a harmonised solution for the end-host.

This work extended ILNPv6, an engineering solution of Identifier Locator Network Protocol (ILNP) implemented as a superset of IPv6 on the Linux kernel. The existing implementation was extended to harmonise mobility and multihoming. First, the mobility implementation was en- hanced to support rapid and continuous mobility; a comparative analysis against MIPv6 showed superior performance during high rate of handoffs. Second, multihoming was implemented and integrated with mobility; the evaluation with a flexible multi-connectivity scenario with load-balancing showed negligible loss and consistent throughput. Finally, the impact of the combined mobility-multihoming mechanism was evaluated with a real-time video stream application showing continuous uninterrupted real-time video playback at 2160p (4k ultra high definition). Overall, this work has demonstrated that mobility-multihoming duality is possible for end-hosts over IPv6 for existing applications without changing the network infrastructure.

Supervised by Prof. Saleem Bhatti with Dr Tristan Henderson as second Supervisor.

Thank you to the external examiner Prof. Mahesh Marina from the University of Edinburgh and Internal examiner Prof. Simon Dobson.

The viva took place on Microsoft Teams on 7/03/2022.