FAQ - linux-wpan/wpan-tools GitHub Wiki

Q: Why is the ACK request bit disabled in linux-wpan by default (ACK support is mandatory by the IEEE specs)?

A: While this is true there might still be implementations out there which do not implement ACK handling and with the ACK request bit set by default we might send out 3 frames (default value) as retransmission while the first one already arrived. If you are sure that all nodes in your network support ACK handling you should enable it on teh linux nodes as well.