On Wed, Jan 20, 2016 at 06:01:00PM +0000, Nounou Dadoun wrote: > But if the TFO data payload is in the first SYN how can it be encrypted > (etc) even before the TCP handshake is complete (let alone the SSL > handshake) unless the calls are unbundled and serialized somehow. The TCP first-flight data will be the TLS ClientHello message. This saves one round-trip on repeat visits: C: SYN + TFO-COOKIE + TLS ClientHello S: SYN-ACK S: ACK + TLS Server Hello ... ... -- Viktor.