How to turn on BBR when compiling the firmware
echo 'CONFIG_TCP_CONG_BBR=y' >> target/linux/ramips/mt7621/config-4.9
make -j1 V=s
If Linksys, 1900v2 is not that kind of code.
echo 'CONFIG_TCP_CONG_BBR=y' >> target/linux/ramips/mvebu/config-4.9
make -j1 V=s
echo 'CONFIG_TCP_CONG_BBR=y' >> target/linux/mvebu/config-4.9
make -j1 V=s
thank you!!