An Improvement of MPTCP Initialization

This draft describes a new method of connection initialization for Multipath TCP (MPTCP). In the current implementation, the MPTCP's first subflow needs to be successfully initialized before an additional flow takes its turn. This yields to a degradation of MPTCP benefit in many use cases (e.g., transferring short flows). To overcome the problem, we propose to duplicate the first SYN packet and send the duplicating ones via multiple interfaces.