ICTM - Soutenance publique de thèse - M. Gregory DETAL

More than forty years since the creation of the first ARPANet nodes, the Internet
continues to evolve. One of the major evolutions happened on the end hosts. The
recent decade has seen the introduction of new types of devices that are multiconnected:
smartphones and tablets. These devices often have both a WiFi and a
mobile data connection. Unfortunately, the TCP/IP protocols were designed 30
years ago when devices only used a single interface. As smart devices are multiconnected,
users expect that their applications can seamlessly handover from
WiFi to 3G. However, users have often to restart manually their applications
because they move out of the range of a wireless network. This mismatch
between what the protocols provide and what the user expects therefore impacts
the user experience.
Recently, a new extension to TCP, called Multipath TCP (MPTCP), has been
proposed and standardized. MPTCP allows a single connection to use multiple
interfaces at the same time actually adding the missing mobility feature to TCP.
This extension, as every new protocol/extension, suffers from the chicken-andegg
problem. To use MPTCP both clients and servers have to support the
extension. Who will deploy it first? Other TCP extensions have taken more than
ten years before being fully deployed. Experience also shows that clients often
support new features before servers.
This PhD thesis focuses on the deployability of MPTCP and evaluates its benefit
in different network environments. First we evaluate the benefits of using MPTCP
on a smartphone as to show that indeed MPTCP improves the end user
experience. Second we evaluate if MPTCP can be used on the Internet by
identifying middleboxes that could prevent it from being used. We then propose to
solve the chicken-and-egg problem by deploying protocol converters on the
Internet that translate TCP to MPTCP. This converter gives incentive to
smartphone vendors to implement MPTCP on their devices and use it to improve
the customer experience. Finally, we propose a new load balancing technique that
improves the link usage in data centers.

Membres du jury :
Prof. Olivier Bonaventure (UCL), Promoteur
Prof. Charles Pecheur (UCL), Président
Prof. Marco Canini (UCL), Secrétaire
Prof. Laurent Mathy (ULg)
Prof. Costin Raiciu (Universitatea Politehnica Bucuresti, Roumanie)
Dr Pierre Francois (IMDEA Networks, Espagne)
Prof. Gildas Avoine (UCL)