The electromechanical switches here were pretty different. SxS disappeared very early on when the network began to be digatlised in about 1979-80. The priority was to remove the SxS switches as they were becoming old and extremely unreliable. P&T (the predecessor to Telecom Eireann, now Eircom) operated a horrendously bad network at the time. Parts were also becoming difficult to come by and it was generally a maintenence nightmare.

However, P&T had installed a signifigant number of large crossbars, ARF (local) and ARM (transit) particularly during the 1970s.

These switches were pretty efficient, reliable and effective so remained in service along side digital switches albeit only as local exchanges right through the 1980s gradually disappearing by the early 90s.

Ericsson also offered a seamless upgrade path from ARM/ARF to AXE where by digital equipment could gradually replace various parts of the older switch until eventually it could be cut over to being a full AXE.

The smaller Ericsson ARK crossbars used in some rural areas generally were replaced by Alcatel E10 systems as almost all of rural ireland operates on that system. SxS switched areas generally became E10 too.

ARF went through a period of being ARE-11 which was a kinda hybrid of a crossbar but with computerised registers etc. So you picked up, dialled this was handled digitally and a computer system controlled the switch.

These switches sounded exactly the same as the older ones the only difference being they handled DTMF & were marginally faster.

Occasionally ARF switches could go wrong and give youa blast of really rapid MF signaling strings all sounded very high tech, but wasn't compared to SS7 [Linked Image] The exchange used these internally to control various moduels and also to signal the network.
Not sure which signaling system it actually was.

Also, compared with most of the rest of Europe digialisation occured much more quickly and much earlier on. Most of the system was fully digital by about 1987 with the remainder being ARF but only locally. All ARF exchanges were working effectively as remote concentrators for nearest AXE or E10.


Also that long burst ring tone is very familar. It's used here as standard the long burst activates caller ID equipment on the line.