In this talk, Mathieu Bartz discusses MPTCP (multi-path TCP) in the Linux kernel. He starts with an introduction to MPTCP, explaining how it breaks the assumption that a connection is linked to a fixed pair of IP addresses and ports. He then presents a few use cases, such as seamless handover scenarios for smartphones and hybrid access networks. Mathieu also explains how to use MPTCP in the upstream kernel, including the changes needed in applications and network configurations. He mentions that MPTCP is already supported by some companies like Apple, Samsung, and LG. He also discusses the challenges faced in upstreaming MPTCP, such as the need for a complete rewrite of the code and maintaining compatibility with the existing TCP stack. Mathieu concludes by expressing his gratitude to the contributors and the progress made so far in integrating MPTCP into the official Linux kernel.