Symbol: IEEE80211_DUR_DS_SLOW_ACK
sys/net80211/ieee80211.h
776
IEEE80211_DUR_DS_SLOW_ACK + \
sys/net80211/ieee80211_output.c
786
ack = (use_ack) ? pre + (IEEE80211_DUR_DS_SLOW_ACK * 2) / ctsrate : 0;