The tech involves using TCP Fast Open (TFO) for zero RTT TCP connection setup. IETF RFC 7413, Initial Congestion Window 10 (ICW10) by default for faster TCP slow start, TCP Recent ACKnowledgment (RACK) for better loss recovery (experimental IETF draft), Tail Loss Probe (TLP) for better Retransmit TimeOut response (experimental IETF draft) and TCP LEDBAT for background connections IETF RFC 6817

All this, claims Microsoft, will reduce latency, improve loss resiliency and to “promote better network citizenship.”

What is a little surprising is that the TCP LEDBAT technology was submitted to Redmond by BitTorrent. LEDBAT was invented by Stanislav Shalunov and is used by Apple for software updates and by BitTorrent for most of its transfers. It is believed be used in 13–20 per cent of Internet traffic.

Basically it is a delay-based congestion control algorithm that uses all the available bandwidth while limiting the increase in delay. It measures one-way delay and using changes in the measurements to limit congestion.

Redmond said that these changes are just “the first wave of features in the pipeline of upcoming Windows Redstone releases”.