MPJOIN should include how fast each connection connected

[frochet]

tcpls_connect function records the rtt of each successful connection. When we wish to use another address than the primary one, we need to perform a MPJOIN handshake. This handshake allows the server to associate several TCP connection to the same TCPLS connection.

The mpjoin clientHello option should include the RTT value that tcpls_connect computed, in order to the server to have preferences for connections upon, for example, a failure over the primary link.

[mpiraux]

Couldn't the server measure the RTT based on the SYN+ACK and ACK packets ? Also, one RTT sample is not very reliable.