file: /proc/sys/net/ipv4/tcp_adv_win_scale
variable: net.ipv4.tcp_adv_win_scale
Official reference

Count buffering overhead as bytes/2^tcp_adv_win_scale (if tcp_adv_win_scale > 0) or bytes-bytes/2^(-tcp_adv_win_scale), if it is <= 0. Possible values are [-31, 31], inclusive. Default: 1

tcp_allowed_congestion_control - STRING Show/set the congestion control choices available to non-privileged processes. The list is a subset of those listed in tcp_available_congestion_control. Default is “reno” and the default setting (tcp_congestion_control).