On Mon, Dec 14, 2020 at 7:42 PM Niall Douglas via Boost-users <boost-users@lists.boost.org> wrote:
> While using e.g. tcp::endpoint{ tcp::v6(), port } results in 20-30ms
> connection times on Windows. (2-3ms on Linux).

If you're on loopback and you'd like to close that gap, you need to turn
on SIO_LOOPBACK_FASTPATH. I've no idea if ASIO can do that for you, I'm
still on a pre-churn ASIO. An alternative is to bind to a real NIC, and
not go via loopback.

No sure to follow. Loopback only allows local (same host) connection, no? 
What do you mean bind to a real NIC? That actual DHCP allocation IP?

If you're on a real NIC over a real network, I find a 20-30ms connection
time abnormal. Windows 10 has a fast TCP stack, compared to previous
Windows. It should be single digit milliseconds.

Yes to both. Not sure how to diagnose this further though. --DD