Multi-Path TCP: Revolutionizing connectivity, one path at a time
1/3/2025
This post details the technical aspects of setting up and understanding Multi-Path TCP (MPTCP). It explains the concept of MPTCP subflows, how they are represented in tools like `ss -M`, and the two primary use cases: aggregation and mobility. The post covers MPTCP implementations on Linux (kernel v5.6+, ideally v6.1+) and iOS/macOS, including server-side configurations like `net.mptcp.allow_join_initial_addr_port` and client-side configurations using `ip mptcp endpoint`. It also touches upon the path manager and scheduler components, and the challenges of configuring MPTCP for seamless mobility and server-announced addresses.