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Decommission legacy UC hardware before copper sunsets

Copper line retirement is accelerating. Organizations planning to decommission legacy UC hardware must also include analog devices, such as alarm systems and elevator phones.

Venus Kohli
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Published: 18 Aug 2026

Organizations that still rely on copper lines to support legacy communications services must have a plan in place to decommission them as carriers ramp up their plans to end copper services.

The FCC has accelerated the retirement of copper lines by shortening the timeline and reducing carrier requirements for retirement approval. IT leaders cannot be caught unprepared if their carrier notifies them of their copper retirement plans.

IT leaders must have a strategy for decommissioning and migrating legacy unified communications (UC) hardware that meets the needs of the current workforce and supports unique communications hardware requirements.

For more than a century, copper was the backbone of enterprise communications. Copper lines connected desk phones to the private branch exchange (PBX), then to the phone system carrier. However, copper lines are expensive to purchase, deploy and maintain.

The advent of the mobile and hybrid workforce has led IT leaders to replace conventional desk phones with IP-based phones or applications on laptops and mobile devices.

However, alarm systems, elevators, fire panels, point-of-sale terminals, emergency phones and lobby phones form a hidden layer of UC. These analog-heavy legacy UC hardware often don't appear in a UC platform's admin console and may not always be compatible with IP-based fiber networks

According to a survey from UC compliance platform Wordwatch, 79% of enterprises manage two or more legacy systems, which introduce complexity and security vulnerabilities. Each year an enterprise doesn't migrate from legacy technology increases its technical debt.

Modern migration technology

The most common migration path from copper lines is to deploy UC as a service. UCaaS integrates capabilities, such as voice, video, messaging, file sharing and conferencing, into a single application without the need for copper lines. Aging servers and wire-bound PBXs cannot integrate with high-speed, cloud-native applications.

The total cost of ownership of a UC platform is significantly lower than that of a copper-wire infrastructure with a PBX and legacy UC hardware. AT&T reportedly spends $6 billion annually to maintain copper-based connections, even though less than 3% of its customers use them.

Session Initiation Protocol (SIP) trunking is a faster and less disruptive migration strategy. However, SIP trunking can sometimes be incompatible with older legacy UC devices, including time-division multiplexing (TDM) hardware. A media gateway can function as a bridge in some cases.

FCC loosens copper retirement process

The process of retiring copper lines has been lengthy for years, with carriers waiting months -- sometimes years -- to receive approval. The process included the following steps:

1. Carriers provide notice to customers.

2. Carriers file a Section 214 discontinuance application with the FCC.

3. Carriers submit a copy of the application to the Secretary of Defense, the state public utilities commission and state governors where the copper will be retired

4. Public comment period follows the retirement procedure to establish an auto-grant date.

Earlier this year, the FCC loosened its regulations for retiring copper lines. Carriers no longer need to provide formal notice to government regulators and only need to provide as little as a 90-day notice to customers of the transition. Applications to retire copper lines now have a 31-day automatic approval period.

Carriers can grandfather copper services to let existing customers continue using legacy services, but they can refuse to add or change copper lines.

UCaaS and SIP trunking cannot address hidden UC hardware, such as emergency phones, elevator communications and lobby phones, because they cannot be migrated to softphones. These types of hardware require plain old telephone service (POTS) replacement with an analog telephone adapter (ATA), which converts signals from legacy equipment into digital data. This enables the hardware to operate as usual while the ATA aligns it to the cloud.

However, each device requires a standalone ATA, which can be a costly, time-consuming bottleneck in copper migrations. Safety-critical communication devices are also subject to regulations, requiring ATAs to pass inspections and comply with safety codes to ensure operational reliability.

Each of these migration approaches shares the same downside -- reliability. While these approaches enable cloud-based communication, they require backups in case of a power or Internet outage. For example, an elevator phone must stay operational during a power outage.

IT leaders must also ensure that copper replacement complies with 911 requirements, such as Kari's Law and RAY BAUM's Act. Kari's Law requires multiline phone systems sold, leased or installed after Feb. 16, 2020, to dial 911 without using a prefix. RAY BAUM's Act requires 911 calls to provide operators with a dispatchable location that includes street addresses and additional information, such as suite or apartment numbers.

7 Steps for a successful decommissioning strategy

Decommissioning legacy hardware is a planned and governed process that involves multiple IT leaders and governmental oversight.

1. Start the official procedure. The first step is to identify copper placements. PBX copper lines are visible, but safety UC devices may hide copper lines. Then document enterprise copper line deployment, dependency maps, and connected vendor tools. Start filing the application and share advance notices to affected customers, vendors and authorities.

2. Map copper dependency. Before migration starts, map where copper-backed legacy UC hardware connects to other communication devices in the enterprise, CRM, contact center IVR menus and automatic door access systems. This helps generate a risk profile and determine whether downtime is tolerable or not.

3. Grandfather existing connections. Freezing ongoing or deployed copper connections is a standard method to provide space for customers to make informed decisions. For branch offices, IT leaders can inform and train employees on newer replacement technologies before decommissioning begins.

4. Assign replacements. IT leaders must determine where UCaaS is suitable. For daily internal and external enterprise communications,  UCaaS is the feature-ready, cost-effective migration strategy.

SIP trunking and ATA may be more effective in some compliance-heavy and safety-critical areas. Implementing a parallel migration means deploying a new system alongside the old system. Small batch migration avoids service downtime and expensive repairs.

5. Safeguard data. PBX and legacy UC hardware carry a critical amount of data, such as the nature of calls, the number of calls, voicemails and customer profiles. Data can be lost due to the complexity of legacy systems. Enterprises must capture all the data into a single repository for reloading and analysis in the new system.

6. Ensure cybersecurity. UCaaS, if implemented in a composable architecture, relies heavily on API and webhooks. IT leaders should direct teams to assess API connections, ensure they are password-protected and encrypted. Any questionable connections, such as shadow APIs, must be removed.

7. Testing and valuation. Test the new system's accuracy post migration. Emergency phones, lift callers and alarm systems must be tested in mock training scenarios. These tests also allow newer technology to receive relevant safety certifications.

Venus Kohli is an engineer turned technical content writer, having completed a degree in electronics and telecommunication at Mumbai University in 2019. Kohli writes for various tech and media companies on topics related to semiconductors, electronics, networking, programming, quantum physics and more.

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