December 24, 2025 – The inevitable has started. AT&T in Oklahoma (former Southwest Bell) is slowly turning off central offices. The first appears to be a small town called Hitchcock, OK, about an hour NW of Oklahoma City. This is a VERY small town that was served by a 5ESS remote switch. This is a screen shot of a posting from LinkedIn gloating about the shutdown of wireline (landline) services completely. So as of December 2025, there are no ILEC services at all in this town. If you want a phone, you either use cellular or CLEC. No landline period. This is just the beginning, sadly.

December 11, 2025 – I heard from an industry contact that the Lansing, MI 4ESS switch (LNNGMIMN50T) is slated to be powered off tonight. Traffic through the switch has already been rerouted elsewhere. This is considered to be the last 4ESS in the lower 48 states. Only the 4ESS in Anchorage, AK remains.

Since 2012, the AT&T network has been slowly been replacing 4ESS network with the “Next Generation 4ESS”. They stepped up their efforts in the last couple of years to finally shut down the remaining 4ESS switches.

At the peak, there were around 150 4ESS switches. In comparison, there are around 45 N4E switches (my estimate). So slightly less than one-third of the switching capacity than before.

The Lansing switch was added to the network in May 1987 and decommissioned in December 2025. So over 38 years in service!

The first 4ESS was installed in Chicago in January 1976, while the last 4A crossbar was installed in May 1976!

Overall – January 1976 to December 2025 – nearly 50 years of service! Long live the 4ESS architecture.

To honor the 4ESS, Dylan Cruz wrote this poem:

——————————–
Western Electric No. 4ESS
January 17th, 1976 – December 10th, 2025
Half a century of faithful service.

Earlier this week, the last remaining trunks were migrated and the switch was verified for cut status. Oakbrook, IL, once expected to be the final site, had already gone dark. Lansing, MI stood alone as the last operating 4ESS, isolated for weeks.

Tonight, AT&T pulls the fuses on that final switch. With that simple act, an entire era of telephony slips into silence.

For most people, it is just another piece of equipment retired.
For us, it is the loss of an old friend.

Countless nights were spent exploring this network, scanning switches, documenting crosstalk behaviors, and smiling at the quirks of the Phased Announcement System.

We learned to recognize the voice of a switch by the texture of its noise. The electromechanical interrupter and tone plant humming steadily in the background, the interrupter’s steady clicking blending with crosstalk that drifted in and out. A faint reorder tone echoing from deep within the system.

And in the distance, a serious “Tandem Tina”forcefully announcing that all international circuits were busy. She delivered it with the urgency of a police officer directing traffic in the middle of a hurricane, because in that world every call mattered.

All of the intercepts carried that same authority. Her voice was the law of the network, the defining presence in the wild and sprawling world of long distance telephony. Hearing her was a reminder that this system was vast, important, and alive.

Miscellaneous hardware added its own colors and overtones. The soft bleed of the battery plant came through like a pulse. Together these sounds formed something far greater than noise. They were the quiet heartbeat of a machine that once carried the entire world and acted as the blood of human connection.

These sounds and quirks were never just curiosities. They measured the respect we came to hold for the network.

The 4ESS was a marvel. It was not simply a component of the Bell System. It was a living, breathing part of it, and perhaps one of the most significant living parts ever created. It shaped the rhythm of long distance communication, held together the flow of human connection, and stood as a testament to the highest ideals of engineering. Its elegance, its precision, and its sheer capability represented the very soul of the system it served.

To know it personally, to study it, explore it, and listen to it was a privilege I will never forget.

Tonight, the last 4ESS goes dark.

Last one out, turn off the lights.

— Dylan Cruz on 12/10/25

December 24, 2025 – The inevitable has started. AT&T in Oklahoma (former Southwest Bell) is slowly turning off central offices. The first appears to be a small town called Hitchcock, OK, about an hour NW of Oklahoma City. This is a VERY small town that was served by a 5ESS remote switch. This is a screen shot of a posting from LinkedIn gloating about the shutdown of wireline (landline) services completely. So as of December 2025, there are no ILEC services at all in this town. If you want a phone, you either use cellular or CLEC. No landline period. This is just the beginning, sadly.

December 11, 2025 – I heard from an industry contact that the Lansing, MI 4ESS switch (LNNGMIMN50T) is slated to be powered off tonight. Traffic through the switch has already been rerouted elsewhere. This is considered to be the last 4ESS in the lower 48 states. Only the 4ESS in Anchorage, AK remains.

Since 2012, the AT&T network has been slowly been replacing 4ESS network with the “Next Generation 4ESS”. They stepped up their efforts in the last couple of years to finally shut down the remaining 4ESS switches.

At the peak, there were around 150 4ESS switches. In comparison, there are around 45 N4E switches (my estimate). So slightly less than one-third of the switching capacity than before.

The Lansing switch was added to the network in May 1987 and decommissioned in December 2025. So over 38 years in service!

The first 4ESS was installed in Chicago in January 1976, while the last 4A crossbar was installed in May 1976!

Overall – January 1976 to December 2025 – nearly 50 years of service! Long live the 4ESS architecture.

To honor the 4ESS, Dylan Cruz wrote this poem:

——————————–
Western Electric No. 4ESS
January 17th, 1976 – December 10th, 2025
Half a century of faithful service.

Earlier this week, the last remaining trunks were migrated and the switch was verified for cut status. Oakbrook, IL, once expected to be the final site, had already gone dark. Lansing, MI stood alone as the last operating 4ESS, isolated for weeks.

Tonight, AT&T pulls the fuses on that final switch. With that simple act, an entire era of telephony slips into silence.

For most people, it is just another piece of equipment retired.
For us, it is the loss of an old friend.

Countless nights were spent exploring this network, scanning switches, documenting crosstalk behaviors, and smiling at the quirks of the Phased Announcement System.

We learned to recognize the voice of a switch by the texture of its noise. The electromechanical interrupter and tone plant humming steadily in the background, the interrupter’s steady clicking blending with crosstalk that drifted in and out. A faint reorder tone echoing from deep within the system.

And in the distance, a serious “Tandem Tina”forcefully announcing that all international circuits were busy. She delivered it with the urgency of a police officer directing traffic in the middle of a hurricane, because in that world every call mattered.

All of the intercepts carried that same authority. Her voice was the law of the network, the defining presence in the wild and sprawling world of long distance telephony. Hearing her was a reminder that this system was vast, important, and alive.

Miscellaneous hardware added its own colors and overtones. The soft bleed of the battery plant came through like a pulse. Together these sounds formed something far greater than noise. They were the quiet heartbeat of a machine that once carried the entire world and acted as the blood of human connection.

These sounds and quirks were never just curiosities. They measured the respect we came to hold for the network.

The 4ESS was a marvel. It was not simply a component of the Bell System. It was a living, breathing part of it, and perhaps one of the most significant living parts ever created. It shaped the rhythm of long distance communication, held together the flow of human connection, and stood as a testament to the highest ideals of engineering. Its elegance, its precision, and its sheer capability represented the very soul of the system it served.

To know it personally, to study it, explore it, and listen to it was a privilege I will never forget.

Tonight, the last 4ESS goes dark.

Last one out, turn off the lights.

— Dylan Cruz on 12/10/25