FIELD: switching equipment of long-range communication. SUBSTANCE: connecting groups connected to duplicated communication field with the aid of two control lines and comprising one decentralized device each are divided into two categories. Concentrators are always connected to one connecting group of both categories. For loading the control devices and concentrators with new programs and/or data one processor continues operating in switching duty, while only the control devices of the first category remain connected to it, and while the concentrators ensure further setting-up of connections only via the connecting groups of the first category. The other processor is connected to the control devices of the second category and accomplishes these loading procedures for them and via them. After that connections via the connecting groups of both categories are set up, then the connecting groups of the first category are interlocked with respect to new engagements, and setting-up only of those connections that are in the stage of setting-up or already exist is continued. After that the other processor accomplishes loading of one processor, and the latter-loading of the connecting groups of the first category. EFFECT: prevented complete failure of system at replacement of programs, data or processors. 10 cl, 1 dwg
