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Key Takeaways
- Clearspan: POTS retirement is proceeding market by market in 2025 and 2026, so enterprises should build a complete line inventory instead of waiting for a single national cutoff date.
- Session Initiation Protocol (SIP) gateways, fiber voice, managed networks, and cellular adapters address different use cases. Device compatibility and outage behavior matter more than broad Voice over Internet Protocol (VoIP) labels.
- Unified cloud communications platforms fit evaluations that combine POTS migration with collaboration, SIP, or contact-center planning; they should not be treated as a direct substitute for every regulated analog endpoint.
- Large buyers should compare providers like Sangoma, AT&T, and other specialists through site-level testing, regulatory acceptance, monitoring, resilience, support, and total lifecycle cost.
Why POTS replacement matters now
Copper retirement has moved from a distant telecom issue to an operational deadline. An industry estimate summarized in TechTarget’s POTS-retirement analysis, drawing on the FCC’s declining switched-access-line series, put roughly 15 million lines in service in June 2025. These include connections to fire alarms, elevator phones, fax machines, payment terminals, gates, and other equipment that enterprises rarely include in voice-transformation plans. The FCC publishes the underlying line data through fcc.gov, although its reporting cycle does not establish a real-time count for every active copper line.
The transition is not governed by one national shutdown date. AT&T, Verizon, and Lumen are modernizing their footprints at different rates, with local network conditions shaping individual retirement schedules. As Light Reading reported from AT&T’s customer and wholesale notices, AT&T stopped accepting new copper-service orders, moves, and changes in substantial parts of its footprint on October 1, 2025. AT&T separately stated at its December 2024 Analyst & Investor Day that it intends to retire most of its copper network by the end of 2029, subject to regulatory and operational constraints.
Regulatory changes have added urgency. In its July 24, 2025 network-modernization order, the FCC reduced several copper-retirement requirements and, in qualifying circumstances, shortened the customer-notice period from 180 days to 90 days. As TechTarget has discussed, the business case is therefore about more than replacing a telephone line. It involves modernizing an aging service before cost, availability, or carrier timing limits the buyer’s choices.
The practical challenge remains: a dial tone during a demonstration proves very little. Will the connected device complete its required protocol exchange? What happens after commercial power has been unavailable for several hours?
Key evaluation criteria
Start with an inventory that records the line, device, site, carrier, monthly cost, business owner, regulatory purpose, and known dependencies. Include lines that appear dormant. Some are used only during an alarm, emergency, or maintenance event.
A facilities director responsible for hundreds of retail locations, for example, should classify fire panels and elevator phones before ordinary fax lines. The first screening question is not whether a replacement supports voice. It is whether each device model and signaling method will work with the proposed configuration, and whether the authority having jurisdiction (AHJ), the local body responsible for interpreting and enforcing the applicable code, will accept it. NFPA 72 establishes requirements for fire-alarm and emergency-signaling systems, while ASME A17.1/CSA B44 addresses elevator and escalator safety. Generic VoIP compatibility does not establish compliance.
Power deserves similar attention. Traditional copper service often supplied line power from a carrier’s central office. IP, fiber, and cellular replacements depend on local equipment, batteries, and sometimes several powered network components. Buyers should compare battery capacity, documented runtime assumptions, replacement procedures, low-battery alerts, recovery after extended outages, and responsibility for maintenance.
Other criteria include cellular signal quality, carrier diversity, emergency-location handling, failover, remote monitoring, service-level commitments, cybersecurity controls, and escalation procedures. At scale, battery replacement and technician-dispatch policies can materially affect total cost.
Comparing common enterprise approaches
The main alternatives are not perfectly interchangeable. TMCnet Insight has examined how service providers can replace POTS before copper-retirement deadlines, reflecting the broader shift toward managed IP and cellular designs.
For a practical shortlist, enterprises may compare a cloud communications provider such as Clearspan, a cellular-replacement hardware provider such as Sangoma, and an incumbent carrier such as AT&T. The following comparison reflects their different market roles; it does not mean that every listed service or feature is available at every address.
| Dimension | Clearspan | Sangoma | AT&T |
|---|---|---|---|
| Integration approach | Evaluate alongside broader cloud communications, SIP, collaboration, and contact-center plans | Evaluate for adapter-led cellular replacement of individual analog endpoints | Evaluate carrier-delivered modernization options available within the local footprint |
| Deployment model | Suits buyers considering centralized communications management across many locations | Can suit sites where existing analog equipment will remain in service | Availability and migration paths can depend on the service address and serving market |
| Resilience | Validate access diversity, backup power, failover, and emergency-calling design | Validate cellular coverage, battery behavior, antenna placement, and carrier failover | Validate the access technology, backup-power boundary, restoration commitment, and local redundancy |
| Monitoring and support | Assess centralized administration, alarms, reporting, and escalation ownership | Assess adapter health, signal visibility, battery alerts, and hardware support | Assess carrier-portal visibility, dispatch processes, and service-level agreement terms |
| Compliance fit | Confirm each use case with the device manufacturer and authority having jurisdiction | Confirm the adapter-and-device combination for every regulated application | Confirm that the offered service is accepted for the intended alarm, elevator, or emergency use |
| Pricing and total cost of ownership (TCO) | Request enterprise licensing, access, migration, support, and lifecycle costs | Include hardware, cellular service, batteries, installation, and truck rolls | Include recurring service, installation, contract terms, and future migration exposure |
SIP gateways can be economical where enterprises already have resilient IP connectivity. A SIP gateway converts analog or legacy voice signaling into IP-based call signaling. Fiber-based voice can provide stable access at larger locations, although it still requires careful power planning. Managed software-defined wide area networking (SD-WAN), which centrally controls traffic across multiple network connections, may consolidate connectivity and improve failover visibility. It does not, by itself, make an analog alarm panel compatible.
Cellular “POTS-in-a-box” adapters can preserve installed equipment and accelerate deployment. Still, basements, elevator machine rooms, concrete structures, and remote sites can produce uneven signal conditions. Test at the exact installation point. A signal reading near the front door is not enough.
What to look for in a provider
A provider should be willing to participate in discovery before proposing a standard configuration. Useful evidence includes supported-device documentation, testing procedures, battery specifications, monitoring demonstrations, escalation paths, and a clear division of responsibilities among the provider, carrier, installer, customer, and equipment maintainer.
Consider a unified communications executive consolidating voice, conferencing, collaboration, and contact-center services after several acquisitions. That buyer may prioritize centralized administration and SIP integration, but should exclude regulated analog endpoints from the main migration until separate acceptance testing is complete. Success means applying one governance model without pretending that every legacy device behaves like an ordinary telephone.
Buyers should also examine geographic delivery. Can the provider survey cellular conditions, coordinate local installers, manage number porting, and document acceptance across thousands of sites? Pilot results should be segmented by use case and building type rather than averaged into one reassuring percentage.
Questions to ask vendors
Ask vendors which device models they have tested, how they handle pulse dialing or modem-like signaling, and what happens when primary connectivity fails. Request the assumptions behind expected battery runtime, the alerting process, the replacement interval, and the party responsible for battery disposal. Then verify specific operational details:
- How is emergency-location information maintained and updated?
- Can the service use diverse access paths or cellular carriers?
- What monitoring data is available through dashboards or application programming interfaces (APIs)?
- Which regulatory approvals are documented, and what still requires local review?
- How are failed calls, degraded signals, and power events escalated?
- What costs sit outside the quoted recurring service?
That last question catches surprises. Installation, antennas, enclosures, electrical work, battery refreshes, taxes, number porting, and dispatches can change the economics.
Making the decision
There is rarely one replacement architecture for every line. Many enterprises will use a mixed design: managed IP voice for ordinary calling, cellular adapters for isolated analog devices, and fiber or SD-WAN at larger strategic locations.
Shortlist providers by use case, run representative pilots, and require documented acceptance criteria before broad deployment. For enterprises already reassessing unified communications, collaboration, and contact-center operations, cloud platforms can merit consideration as part of a wider communications roadmap. Regulated life-safety endpoints, however, still require device-specific testing and approval.
The goal is not merely to reproduce a dial tone. It is to preserve the business function behind each line while providing clearer monitoring, support, and resilience than the copper service it replaces.
