Making Multipath TCP robust for stateless webservers

This document proposes a modification of the MPTCP handshake that allows it to work efficiently with stateless servers. We first identify the issues around stateless connection establishment using SYN-cookies. Further, we suggest an extension to Multipath TCP to overcome these issues and discuss alternatives. As a side-effect, the proposed modification to the handshake opens the door to reduce the size of the MP_CAPABLE option in the SYN. This reduces the growing pressure on the TCP-option space in the SYN- segment, giving space for future extensions to TCP.