The Number 5 Electronic Switching System (#5ESS) was the workhorse of the Public Switched Telephone Network (PSTN) in the United States. The University of Arizona quickly took advantage of the new technology in 1989, enabling telephone service for over 22,000 lines on campus and to far-reaching locations like the Campus Agricultural Center on North Campbell and the Mount Graham International Observatory. After a record 12,542 days, the #5ESS was no longer sustainable. Early diligence in training and a passion for excellence paid off, as UITS telecom technicians kept the system alive long after institutions moved away from it. When university staff began working remotely, telecom needs shifted to match the new remote environment. The Zoom Phone platform has met the institution’s demands very effectively, and the decommissioning and removal of the #5ESS was completed in June 2024.