[ns] Packets discarded due to "-Nl IFQ -Nw ---"

[Ulrich Herberg]

In a MANET simulation using ns-2.33, many packets get dropped in a 
simulation for a strange reason, e.g.:

d -t 7.810587088 -Hs 3 -Hd 13 -Ni 3 -Nx 369.08 -Ny 407.62 -Nz 0.00 -Ne 
100.0 -Nl IFQ -Nw --- -Ma 13a -Md d -Ms 3 -Mt 800 -Is 2.2 -Id 13.3 -It 
cbr -Il 64 -If 0 -Ii 1671 -Iv 30 -Pn cbr -Pi 24 -Pf 1 -Po 0

Does anyone know what "-Nl IFQ -Nw ---" means?
My impression is that it comes from mac/mac-802_11.cc

/*
* Address Filtering
*/
if(dst != (u_int32_t)index_ && dst != MAC_BROADCAST) {
    /*
    * We don't want to log this event, so we just free
    * the packet instead of calling the drop routine.
    */
    discard(pktRx_, "---");
    goto done;
}


Thanks
Ulrich