Voice Networks and Data Networks: From Analog Telephone Circuits to Modern IP Communication
From AI tools as IS.
For much of the history of telecommunications, a voice network and a data network were genuinely different kinds of networks.
Telephone networks were built primarily to carry human conversations. Computer networks were built primarily to exchange data between machines.
Today, that distinction has become much less clear.
A modern telephone conversation may be converted into digital data, divided into packets, carried over fiber and IP networks, processed by software, transmitted over 4G or 5G radio, and finally converted back into sound at the receiving telephone.
Yet traditional telephone infrastructure has not disappeared everywhere. As of September 2026, legacy circuit-switched, copper-based, and other specialized voice systems continue to operate in several parts of the world while telecommunications companies migrate customers toward digital and IP-based services.
Understanding what changed requires looking at what voice networks and data networks actually mean.
What Is a Voice Network?
A useful definition is:
A voice network is a communication network designed primarily to provide voice communication services. Traditional telephone voice networks were generally circuit-switched networks specifically engineered for telephone communication.
Historically, telephone networks primarily carried human speech.
When someone spoke into an old telephone, the microphone converted changes in air pressure into a continuously varying electrical signal.
The conceptual process was:
Human Voice
↓
Continuous sound wave
↓
Telephone microphone
↓
Continuous analog electrical signal
↓
Telephone network
↓
Receiving telephone
↓
Sound
This is why traditional telephone networks are often described as analog voice networks.
However, this needs an important qualification.
Telephone networks did not remain completely analog.
They became substantially digital long before the Internet became dominant.
What Was a Traditional Telephone Signal?
Human speech is naturally analog.
Air pressure varies continuously as we speak.
An early telephone microphone converted these continuous variations into a corresponding continuously changing electrical signal.
Therefore:
Sound pressure
→ continuous analog electrical signal
The receiving telephone performed approximately the reverse operation:
Analog electrical signal
→ speaker movement
→ sound pressure
So it is reasonable to say:
Early telephone voice was represented primarily by continuous analog electrical signals, and traditional voice networks were designed primarily to transport those telephone voice signals.
It is more accurate to say voice signal rather than simply telephone signal, because a telephone network also carries signaling information associated with dialing, ringing, call establishment, supervision, and disconnection.
Traditional Telephone Networks Used Circuit Switching
One of the defining characteristics of the traditional telephone network was circuit switching.
Suppose Alice called Bob.
The telephone network established a communication path through the switching system:
Alice’s Telephone
↓
Local Telephone Exchange
↓
Telephone Trunks
↓
Remote Telephone Exchange
↓
Bob’s Telephone
Network resources were allocated to that conversation while the call was in progress.
That is fundamentally different from the way ordinary Internet packets are handled.
In a packet-switched network, packets belonging to many users normally share network links.
In a traditional circuit-switched telephone system, resources were associated with an established call.
A Dedicated Circuit Did Not Mean a Dedicated Physical Wire
There is an important misconception here.
A circuit-switched telephone call did not necessarily mean that one individual copper wire ran all the way from one caller to another.
The network could multiplex many calls over shared transmission facilities.
What was dedicated or reserved was a logical communication channel or network capacity associated with the call.
So:
Dedicated circuit
does not necessarily mean:
Dedicated physical cable from caller A to caller B
The physical infrastructure could be shared while the switching system maintained a logical circuit for each conversation.
What Is a Data Network?
A useful modern definition is:
A data network is a network designed to exchange digital data between devices using communication protocols. The data may represent text, numbers, files, images, audio, voice, video, sensor measurements, or other information.
Examples of devices participating in data networks include:
- desktop computers;
- laptops;
- smartphones;
- servers;
- routers;
- sensors;
- industrial controllers;
- cameras;
- IoT devices.
Examples of data-network activities include:
- loading a webpage;
- sending email;
- transferring files;
- querying a database;
- streaming video;
- sending sensor measurements;
- making a VoIP call.
That last example illustrates why the old distinction between voice and data has become increasingly difficult to maintain.
Isn’t Voice Also Data?
Today, yes.
In the broad technical meaning of the term, digitally represented voice is data.
Consider a modern telephone call.
Human speech can go through:
Voice
↓
Microphone
↓
Analog electrical representation
↓
Analog-to-digital conversion
↓
Digital audio samples
↓
Voice codec
↓
Compressed digital data
↓
Packets
↓
Communication network
Once voice has been sampled, digitally encoded, and packetized, the network is moving digital data representing speech.
The same principle applies to images and video.
Image
→ pixel data → encoded file → bits
Video
→ image/audio samples → compression → digital stream → packets
Text
→ character encoding → numbers → bits
Therefore:
Voice, images, video, and text can all become data when represented digitally.
Why, Then, Do We Still Say “Voice and Data”?
This terminology comes largely from telecommunications history.
Traditionally:
Voice traffic
meant telephone conversations.
Data traffic
usually meant non-voice information exchanged by computers.
So engineers commonly distinguished:
Voice network
from
Data network
because these could genuinely be different networks using different technologies.
Today the expression “voice and data” is still widely used, but technically voice can itself be digital data.
The word data is therefore being used in two slightly different ways.
Broad technical meaning
Data includes digitally represented:
- voice;
- text;
- images;
- video;
- files;
- measurements.
Traditional telecommunications meaning
“Data” often meant:
computer/non-voice traffic
This historical usage explains much of the terminology that remains today.
Telephone Networks Did Not Jump Directly From Analog to the Internet
The evolution of telephony occurred in several important stages.
A simplified progression is:
Analog circuit switching
↓
Digital circuit switching
↓
Hybrid telephone/IP networks
↓
Packet-switched IP voice networks
Understanding the middle stage is particularly important.
Stage 1: Analog Telephone Network
Early telephone systems could be simplified as:
Voice
↓
Analog telephone
↓
Analog local line
↓
Circuit-switched telephone network
↓
Analog local line
↓
Telephone
↓
Voice
Much of the communication path was analog.
Stage 2: The Telephone Network Became Digital
Telephone companies gradually digitized their internal networks.
The customer might still have an ordinary analog telephone:
Analog Telephone
↓
Copper Telephone Pair
but the telephone exchange could convert the voice into digital form.
The path then became approximately:
Analog Telephone
↓
Analog Local Loop
↓
Telephone Exchange
↓
Analog-to-Digital Conversion
↓
Digital Telephone Network
↓
Digital-to-Analog Conversion
↓
Analog Local Loop
↓
Analog Telephone
This was a major technological change.
But the network could still remain circuit switched.
Digital Does Not Automatically Mean Internet
This distinction is critical.
A network can be:
digital + circuit switched
or:
digital + packet switched
Traditional digital telephone systems commonly used technologies such as PCM and Time Division Multiplexing (TDM).
Multiple telephone conversations could be digitized and carried together across high-capacity digital transmission systems.
Yet each call still behaved as a circuit-switched telephone connection.
Therefore:
Telephone networks became digital long before they became packet-switched IP networks.
Stage 3: IP Entered the Middle of the Telephone Network
The next major change was the use of packet networks to carry telephone calls.
A customer could still use a traditional telephone interface while the carrier converted the voice to IP internally.
For example:
Traditional Telephone
↓
Telephone Network
↓
Media Gateway
↓
IP Packets
↓
Carrier IP Network
↓
Media Gateway
↓
Telephone Network
↓
Traditional Telephone
The caller might never know that part of the conversation travelled as IP packets.
The U.S. Federal Communications Commission has used the expression “IP-in-the-middle” for arrangements in which traditional telephone service uses IP technology within portions of the network.
This demonstrates an important principle:
A traditional-looking telephone service can use modern packet networking internally without changing the user’s telephone experience.
IP Network Does Not Necessarily Mean the Public Internet
Another common misconception is:
If telephone calls use IP, they must travel over the public Internet.
That is not necessarily true.
A telecommunications company can operate its own managed IP network.
The carrier might use:
- private IP backbones;
- MPLS networks;
- fiber networks;
- managed Ethernet networks;
- IMS infrastructure;
- private data centres.
Therefore:
IP network ≠ public Internet
The Internet uses IP, but IP technology can also be used inside completely private networks.
A telephone call may consequently travel as IP packets without being routed over the ordinary public Internet.
Stage 4: Modern Packet-Based Voice
Modern telephone systems increasingly treat voice as packetized digital information.
A simplified modern communication path is:
Human Voice
↓
Microphone
↓
Digital Samples
↓
Voice Codec
↓
Packets
↓
IP Network
↓
Packets
↓
Voice Decoder
↓
Speaker
↓
Human Voice
The network does not need to transport one continuous analog waveform from one telephone all the way to another.
Instead, it transports digital information representing the voice.
Modern Landline Phones Can Still Look Completely Traditional
An interesting aspect of modern telecommunications is that the telephone itself does not necessarily have to be modern.
Imagine an ordinary analog telephone plugged into a residential gateway.
The architecture can be:
Analog Telephone
↓
Telephone Port on Gateway/ONT
↓
Analog-to-Digital Conversion
↓
Voice Encoding
↓
IP Packets
↓
Fiber/Cable/Broadband Network
↓
Carrier Voice System
The gateway handles the technological conversion.
The telephone itself may know nothing about:
- IP;
- Ethernet;
- fiber;
- packet switching;
- Internet protocols.
To the person using it, it is simply a telephone.
The Same Fiber Can Carry Internet, Television, and Telephone Services
Modern broadband infrastructure illustrates network convergence.
A single fiber connection entering a home may support:
Internet
Telephone
Television
The services can still be logically separated and managed differently, but they can share substantial portions of the same physical infrastructure.
This contrasts sharply with older networks in which separate infrastructures were often constructed for separate services.
Cellular Voice Went Through a Similar Transformation
Mobile telephone networks experienced their own transition.
Earlier cellular systems were strongly oriented toward circuit-switched telephone calls.
Later mobile generations supported both:
Circuit-Switched Domain → Voice
and
Packet-Switched Domain → Data
A simplified 3G architecture could therefore have separate mechanisms for ordinary voice and Internet data.
LTE changed the model significantly.
LTE was designed as a packet-oriented system.
Voice increasingly moved to technologies such as:
VoLTE — Voice over LTE
and, with 5G:
VoNR — Voice over New Radio
Now the voice itself can be handled as an application/service on top of a sophisticated packet-based telecommunications infrastructure.
A Modern Mobile Call
A modern mobile voice call can conceptually look like:
Human Voice
↓
Smartphone
↓
Voice Codec
↓
Digital Packets
↓
4G LTE or 5G Radio
↓
Base Station
↓
Mobile Packet Core
↓
IMS / Voice Platform
↓
Remote Network
↓
Recipient’s Phone
This is quite different from the traditional analog telephone model.
The Telephone Network Has Become Increasingly Software-Based
The old telephone network depended heavily on specialized switching equipment.
Modern telephone systems increasingly depend on software.
Examples include:
- SIP signaling;
- IMS;
- software-controlled call routing;
- subscriber databases;
- authentication systems;
- virtual network functions;
- cloud infrastructure;
- software-defined networking;
- IP routers;
- application servers.
The physical network remains essential.
It still requires:
- fiber;
- radio towers;
- antennas;
- switches;
- routers;
- data centres;
- submarine cables;
- satellites.
But much of the intelligence that decides how calls are established, routed, authenticated, billed, and terminated is now implemented in software.
Voice Networks and Data Networks Have Converged
Historically, we might have drawn:
Telephone → Voice Network → Telephone
and separately:
Computer → Data Network → Computer
Today, a more realistic picture is:
Voice
Video
Images
→ Digital Data → Packet Network
/
Text
/
Applications
The same network infrastructure can support many types of information.
This process is generally called network convergence.
Does a Dedicated Telephone Network Still Exist Today?
Yes—but increasingly as legacy or specialized infrastructure, rather than as the dominant architecture.
It is important to distinguish between:
- a network built primarily for telephone service;
- a copper telephone access line;
- circuit-switched PSTN infrastructure;
- a network that literally carries only voice.
The fourth category is now relatively uncommon because even traditional telephone infrastructure has frequently been adapted to carry additional services.
Nevertheless, several concrete examples show that legacy telephone-specific infrastructure remains operational in 2026.
United Kingdom: BT’s PSTN Still Exists Until January 2027
As of September 2026, the United Kingdom is an unusually clear example of a country in the final stage of PSTN retirement.
BT plans to retire its traditional Public Switched Telephone Network on:
January 31, 2027.
UK regulator Ofcom stated in January 2026 that BT’s PSTN remains in service while customers are migrated from analog landlines to digital/VoIP services. Ofcom describes the technology as beyond its intended lifespan and increasingly unreliable.
BT reported in March 2026 that approximately 80% of its voice customers had already moved to All-IP services as of January 2026, but thousands of organizations continued to depend on PSTN-based services.
So in September 2026:
Traditional PSTN infrastructure still exists in the UK, but it is scheduled for retirement on January 31, 2027.
The migration is:
Traditional PSTN
↓
Digital landline
↓
VoIP / All-IP infrastructure
Ofcom also notes that other UK operators, including Virgin Media O2 and KCOM, operate legacy networks and intend to retire them, although their final shutdown dates are not necessarily identical to BT’s.
Australia: Telstra Still Supports Copper PSTN Voice
Australia provides another particularly interesting example.
Telstra currently states that although it is retiring certain older access services, it is not exiting copper PSTN voice services in the affected context. Customers who want to retain copper PSTN telephone service can purchase a standalone Home or Business Phone service.
Telstra also operates a specialized Customer Access Network Radio (CAN Radio) voice service for people in remote areas.
These systems use radio links connecting customers in isolated locations to telephone infrastructure.
Telstra plans to exit CAN Radio by:
November 16, 2027.
This is an excellent real-world example of a specialized network that remains primarily associated with traditional voice service.
So, even in a country with highly developed modern broadband infrastructure, legacy voice-specific systems can continue because of geography, existing equipment, and the needs of remote customers.
France: Orange Is Retiring Its Historic Copper Network Through 2030
France illustrates a slower nationwide transition.
France’s telecom regulator, Arcep, describes Orange’s copper infrastructure as the historic network used for fixed telephone service and later broadband technologies such as ADSL, SDSL, and VDSL.
Orange is progressively shutting down this network, with full technical closure planned by the end of 2030.
The retirement is happening area by area.
Technical shutdown began in some locations in 2025, while successive groups of communities will migrate until the nationwide shutdown is completed.
France also demonstrates why copper network and voice-only network should not be treated as synonyms.
The same copper infrastructure that historically carried telephone service was later also used for DSL Internet access.
So it is legacy telecommunications infrastructure, but not necessarily a network carrying only voice.
United States: Legacy Copper Telephone Infrastructure Is Still Being Retired
The United States is also still undergoing its transition away from legacy telephone infrastructure.
In March 2026, the Federal Communications Commission adopted measures intended to accelerate migration from aging copper telephone networks toward modern IP-based services.
The FCC explicitly described the transition as moving away from:
legacy copper telephone networks
toward:
IP-based services.
The fact that this regulatory transition remains active in 2026 demonstrates that traditional copper-based telephone infrastructure has not vanished across the United States.
Migration happens unevenly because the country contains:
- dense urban networks;
- suburban systems;
- rural telephone companies;
- remote communities;
- specialized business services;
- legacy alarm and emergency systems.
Canada: Legacy Fixed Infrastructure and 3G Are Also Being Retired
Canada is undergoing the same general technological transition.
A 2026 CRTC decision concerning Bell Canada notes that legacy copper infrastructure is being replaced by newer fiber-based infrastructure.
Bell Canada is also withdrawing or destandardizing several older services as the equipment becomes difficult to maintain. For example, a July 2026 CRTC decision describes Bell’s Megalink service as increasingly obsolete and preserves it for existing customers while supporting migration to alternatives.
The transition is equally visible in Canadian mobile networks.
Bell continues to operate its national 3G/HSPA network in most of Canada as of September 2026, but plans to discontinue it nationally on:
March 1, 2027.
Manitoba’s Bell 3G/HSPA service was already discontinued on December 31, 2025.
Bell specifically warns that devices dependent on 3G may lose:
- voice;
- text;
- data;
- 9-1-1 access.
Devices must move toward LTE/VoLTE or newer technologies.
This is another important distinction: 3G is not a dedicated voice-only network. It carries voice, text, and data. But older mobile voice architectures are nevertheless being replaced by packet-based LTE/5G and VoLTE systems.
The UK Has Already Shut Down 3G Mobile Networks
The transition is occurring at different speeds in different countries.
As of May 2026, Ofcom reports that all four major UK mobile operators—
- Vodafone;
- EE;
- Three;
- O2—
have completed their 3G shutdowns.
The UK is now progressively retiring 2G as well.
This shows that there is no single worldwide date when traditional voice technologies disappear.
Different countries and operators are at different points in the migration.
The Meaning of “Voice Network” Is Changing
Historically, a voice network meant something close to:
A dedicated circuit-switched telecommunications network designed primarily for telephone voice communication.
Today the term may instead describe:
The systems, applications, signaling platforms, and network resources used to deliver voice services, even when the underlying transport is a shared packet-switched IP network.
This distinction is important.
A modern organization can speak of its “voice network” even if that network consists of:
- IP phones;
- Ethernet switches;
- SIP servers;
- routers;
- fiber;
- cloud PBXs;
- Internet connections.
The service is still voice, but the underlying infrastructure is a data network.
A Better Modern Definition of Voice Network
A modern definition would be:
Voice network — a communication network or system designed primarily to provide voice communication services. Traditional voice networks were generally circuit-switched, while modern voice services are increasingly digitized, packetized, and transported over shared IP-based networks.
This preserves both the historical and current meanings.
A Better Modern Definition of Data Network
A corresponding definition is:
Data network — a network designed to exchange digital data between devices using communication protocols. The data may represent text, files, images, audio/voice, video, sensor information, or other digital content.
And the relationship between them has changed.
Historically:
Voice network ≠ Data network
Today:
Voice service → frequently carried over a data network
How Voice Works on a Modern Data Network
Suppose someone makes a modern VoIP or VoLTE telephone call.
The process can be simplified as:
1. Speech is produced
The person creates an analog sound wave.
2. The microphone captures it
The microphone converts sound pressure into an electrical signal.
3. The signal is digitized
An analog-to-digital converter samples the waveform and creates numerical values.
4. A codec compresses the voice
A voice codec encodes the speech efficiently.
5. Voice becomes packet data
The encoded information is placed into packets.
6. Packets travel through the network
Those packets may travel over:
- Ethernet;
- Wi-Fi;
- LTE;
- 5G;
- fiber;
- cable;
- carrier IP networks;
- private networks;
- portions of the Internet.
7. The receiver reconstructs the voice
The destination device:
receives packets
↓
extracts encoded audio
↓
decodes the audio
↓
creates a speaker signal
↓
produces sound
The recipient hears the conversation.
The Physical Signal Can Change Several Times
The voice information may also change physical representation during its journey.
For example:
Human voice
↓
electrical signal inside smartphone
↓
digital data
↓
5G radio wave
↓
electrical representation at base station
↓
optical signal through fiber
↓
electrical signal in router
↓
optical signal
↓
radio signal
↓
receiving smartphone
↓
sound
The information remains the conversation.
The data representation allows computers and network devices to process it.
The physical signal changes according to the medium.
The Network No Longer Needs to Know That the Payload Is “A Telephone Call”
This is one of the profound consequences of packet networking.
At many parts of a modern IP network, routers are primarily concerned with things such as:
- source and destination IP addresses;
- routing tables;
- packet headers;
- traffic policies;
- quality-of-service markings.
A router does not need to understand the meaning of every spoken word.
To much of the network, voice is simply:
packets that must be delivered.
This allows a shared infrastructure to carry:
Voice
Video
Web
Files
Cloud Applications
IoT Data
simultaneously.
Why Keep Separate Voice Services at All?
If voice is now data, one might ask why telecommunications companies still treat telephone service separately.
There are several reasons.
Telephone services have special requirements involving:
Reliability
People expect telephone calls to work consistently.
Quality of Service
Real-time voice is sensitive to:
- delay;
- jitter;
- packet loss.
Emergency Calling
Telephone networks must support services such as:
9-1-1 / 112 / 999
depending on the country.
Telephone Numbers
The global telephone numbering system must still work.
Interconnection
Calls need to move between different carriers and different technologies.
Regulatory Requirements
Telephone providers may have obligations that ordinary Internet applications do not.
Power and Resilience
Traditional copper telephone systems sometimes supplied power from the telephone exchange.
Digital phones connected through home broadband equipment may depend on electricity at the customer’s premises, which creates additional requirements for backup power and vulnerable customers.
This issue is one reason regulators such as Ofcom are closely supervising the migration from traditional PSTN lines to digital telephony.
Voice Has Become an Application on the Network
Perhaps the simplest way to understand the modern transformation is this:
Historically:
The network was built specifically for telephone voice.
Today:
Voice is increasingly one service or application running over a general-purpose digital packet network.
Compare:
Traditional model
Telephone
↓
Voice Network
↓
Telephone
Modern model
Telephone/Smartphone
↓
Voice Application/Service
↓
IP Packet Network
↓
Voice Application/Service
↓
Telephone/Smartphone
That is a fundamental architectural change.
From Separate Networks to Converged Networks
Historically, an organization might have needed different infrastructure for:
Telephone
Computer networking
Television/video
Today, the same Ethernet and IP infrastructure can potentially support all three.
For example:
Ethernet/IP Network
├── Computers
├── IP Phones
├── Wi-Fi
├── Video conferencing
├── Security cameras
├── Servers
└── Internet access
This is generally called a converged network.
Voice Networks Are Disappearing as Separate Transport Networks, Not as Voice Services
This distinction is worth emphasizing.
Voice communication is certainly not disappearing.
People still make billions of telephone and Internet voice calls.
What is disappearing is the need for a completely separate physical network whose primary job is transporting telephone voice.
Instead:
Voice service remains
while:
Dedicated legacy transport infrastructure gradually disappears.
Voice increasingly uses the same:
- fiber;
- Ethernet;
- IP;
- radio;
- routing;
- data-centre infrastructure
used by other digital services.
Where Things Stand in September 2026
The worldwide transition can be summarized approximately as follows:
| Technology | Status in 2026 |
|---|---|
| Analog circuit-switched PSTN | Still exists, but rapidly declining |
| Copper telephone access | Still widely present in some countries, being retired |
| Digital TDM telephone networks | Legacy/declining |
| 2G circuit-switched mobile voice | Still exists in some countries; retirement underway |
| 3G voice/data | Being retired rapidly |
| VoIP | Mainstream |
| VoLTE | Mainstream mobile voice technology |
| 5G/VoNR | Growing |
| Fiber-based voice | Increasing |
| Cloud/IP PBX | Mainstream business technology |
| Shared IP transport | Dominant direction |
The timelines differ significantly by operator and country.
For example:
UK / BT: PSTN retirement planned for January 31, 2027.
France / Orange: historic copper network planned for full technical retirement by the end of 2030.
Australia / Telstra: some standalone copper PSTN voice remains available; CAN Radio voice service retirement is planned for November 16, 2027.
Canada / Bell: nationwide 3G/HSPA shutdown planned for March 1, 2027.
United States: the FCC was still actively changing rules in March 2026 to accelerate migration away from legacy copper telephone networks to IP-based services.
The direction is clear even though the transition is not complete everywhere:
Dedicated legacy telephone infrastructure
↓
Digital converged infrastructure
↓
All-IP telecommunications
Final Definitions
After considering both historical and modern systems, these definitions are useful.
Voice Network
A voice network is a communication network or system designed primarily to provide voice communication services. Traditional voice networks were typically circuit-switched and originally carried analog telephone voice signals; modern voice services are increasingly digital, packet-switched, and transported over shared IP-based infrastructure.
Data Network
A data network is a network designed to exchange digital data between devices using communication protocols. The data may represent text, numbers, files, images, audio/voice, video, sensor measurements, or other digital information.
Converged Network
A converged network is a common digital network infrastructure capable of carrying multiple types of services, such as voice, video, and computer/application data.
Final Thought
The phrase “voice network” once described a fundamentally different infrastructure from a computer data network.
That was a world in which:
Telephone → telephone network
and:
Computer → computer network
were largely separate.
That world has changed.
Telephone voice first moved from analog transmission toward digital circuit switching.
Then telephone carriers adopted packet networks and IP transport.
Mobile networks progressed from circuit-switched cellular voice toward VoLTE and 5G packet-based communication.
Fiber, broadband, carrier IP networks, data centres, and software platforms increasingly replaced infrastructure dedicated solely to carrying telephone calls.
Yet the transition is still happening.
Legacy PSTN, copper telephone, TDM, 2G/3G, and specialized voice systems continue to operate in some places in 2026, including parts of the United Kingdom, France, Australia, Canada, and the United States.
The most accurate way to describe the transformation is therefore not:
“Voice networks no longer exist.”
Instead:
Traditional dedicated voice networks are gradually being retired, while voice itself is becoming a digital service carried over converged packet-switched IP networks.
The conversation is still voice.
What changed is the network underneath it.
References and Further Reading
- Ofcom — PSTN switch-off and migration to Voice over IP (VoIP), January 29, 2026. Ofcom states that BT plans to retire its PSTN by January 31, 2027 and discusses the migration of analog telephone customers to digital services.
- BT — Digital Switchover / All-IP. BT describes the replacement of its traditional analog telephone network by digital Voice over IP services.
- BT Business — Final phase of the PSTN switchover, March 20, 2026. BT reported that around 80% of its voice customers had moved to All-IP services as of January 2026 while thousands of organizations remained on PSTN-based services.
- Ofcom — The future of landline calls. Information about BT, Openreach, Virgin Media O2, KCOM, digital landlines, and the transition away from legacy networks.
- Australian Telstra — CAN Radio and ADSL Service Exit. Telstra describes remote CAN Radio voice systems, their planned November 16, 2027 retirement, and continued availability of standalone copper PSTN voice services in relevant areas.
- Arcep — Closure of the French copper network. France’s regulator describes Orange’s historic copper telecommunications network and the transition toward fiber.
- Orange Wholesale France — Copper Network. Orange describes the progressive closure of its nationwide copper network, with technical shutdown expected to be completed by the end of 2030.
- Federal Communications Commission — Accelerating Network and Service Modernization, March 26, 2026. The FCC discusses the continuing U.S. transition from aging legacy copper telephone networks to IP-based services.
- Bell Canada — 3G/HSPA Network Discontinuation. Bell states that its 3G/HSPA network is scheduled to cease nationally on March 1, 2027, following the December 31, 2025 shutdown in Manitoba.
- CRTC — Telecom Order 2026-28. The CRTC discusses Bell Canada’s declining legacy landline services and the replacement of legacy copper infrastructure with fiber-based infrastructure.
- Ofcom — 2G and 3G switch-off. Ofcom confirms that all four major UK mobile operators have completed their 3G shutdowns and that 2G retirement is progressing.
