Last Crossbar Telephone Switch (Central Office) In The 2022 PSTN (TESLA UK11 PBX)

Probably one of the last crossbar telephone switches this size in the public switched telephone network still in operation as of december 2022.

This system is a part of a fairly large installation of private branch automatic exchange (central office) with 800 subscriber lines and 96 trunks. Installed in early 1980s this switch is capable of direct inward dialling, automatic and semiautomatic traffic with 3 operators positions to handle calls.

This switch is finnaly scheduled to be replaced in 2023. I will cover extensively all the parts and call procedures in the next couple of episodes and do my best to save this switch from scraping. I also have the complete documentation which consists of literally thousands of pages and large schematic diagrams. I will share the content as soon as I find the way to do that..