охрана внешнего периметра(Perimeter Security refers to natural barriers or built fortifications to either keep intruders out or to keep captives contained within the area the boundary surrounds. WK Alexander Demidov)
оцепление(In the interim, we'll need to set up a security perimeter around your house. / Security perimeters have been set up in a four-mile radius of the generators. 4uzhoj)