The first generation of the automatic telephone exchange used in Russia was a decade-step exchange. The decade-step exchange was replaced with a crossbar exchange which in its turn was followed by a quasi-electronic exchange and digital exchange.
You are unlikely to find a decade-step exchange today while there are plenty of crossbar exchanges in the country.
So, let us take you to Kaliningrad to show you a crossbar exchange belonging to Rostelecom, Russia's leading long-distance telephony provider.
There are two crossbar exchanges in the building on the right.
Wires connecting telephone subscribers and the exchange go to the cross room.
A couple of decades ago, these wires were extremely valuable and were used in household universally.
After the cross, the signal reaches the exchange where it gets switched by a device for switching telephone calls.