Constant MIN_INITIAL_CONGESTION_WINDOW 

pub const MIN_INITIAL_CONGESTION_WINDOW: u64 = _; // 2_400u64

Available on crate features quic and std only.

The smallest initial congestion window this crate accepts: two datagrams of the size every QUIC path carries (RFC 9000 §14.1). It is a policy floor, not a protocol one; a window of zero was measured to leave a connection unable to complete its handshake.