static guint32 get_len_largest_observed(guint8 frame_type){

    switch((frame_type & FTFLAGS_ACK_LL) >> 2){
        case 0:
            return 1;
        break;
        case 1:
            return 2;
        break;
        case 2:
            return 4;
        break;
        case 3:
            return 6;
        break;
        default:
        break;
    }
    return 1;
}
static guint32 get_len_largest_observed(guint8 frame_type){

    switch((frame_type & FTFLAGS_ACK_LL) >> 2){
        case 0:
            return 1;
        break;
        case 1:
            return 2;
        break;
        case 2:
            return 4;
        break;
        case 3:
            return 6;
        break;
        default:
        break;
    }
    return 1;
}