There was a time when VoIP was viewed as a “cheap alternative” to traditional telephony—fine for startups or home users, but not something you trusted with critical business communications. That time is well and truly over.
With the rollout of high-speed broadband, the decommissioning of legacy PSTN services, and the rise of cloud-based communications platforms, VoIP is now the default telephony model, not an optional upgrade.
In Australia, the National Broadband Network (NBN) has accelerated this transition dramatically. The traditional copper-based analogue phone network is being progressively retired, and almost every modern phone service—whether marketed as “cloud PBX”, “hosted voice”, or “softphone”—is VoIP under the hood.
From an IT perspective, the real question is no longer if you’ll use VoIP, but how well your network and organisation are prepared to support it.
What Is VoIP, Really?
VoIP stands for Voice over Internet Protocol. At its core, it is a technology that allows voice calls to be transmitted as data packets over an IP network rather than over a dedicated circuit-switched telephone network.
In practical terms:
- Your voice is captured by a handset, headset, or softphone
- The audio is digitised and compressed using a codec
- The data is packetised and transmitted over IP
- At the destination, the process is reversed
The call may:
- Terminate on another VoIP endpoint
- Or be converted back to analogue to reach a traditional phone number via the PSTN
This abstraction is why VoIP can run on:
- Desk IP phones
- Softphones on PCs and mobiles
- Traditional handsets via Analogue Telephone Adaptors (ATAs)
Why VoIP Took Over Traditional Telephony
From an engineering standpoint, the old PSTN model made less and less sense over time. It required:
- Dedicated copper pairs
- Centralised switching infrastructure
- Fixed geographic associations
VoIP, by contrast:
- Runs on existing IP infrastructure
- Scales horizontally
- Is location-agnostic
For service providers, VoIP massively reduces operational cost. For businesses and end users, it introduces flexibility that traditional telephony could never match.
How Do You Get a VoIP Number?
A VoIP number is typically obtained through:
- An ISP
- A hosted VoIP provider
- A cloud PBX vendor
In Australia, numbers can be:
- Geographic (e.g. 02, 03, 07)
- Non-geographic (1300 / 1800)
- Mobile virtual numbers
Number Portability (One of VoIP’s Biggest Wins)
One of the most underrated advantages of VoIP is number portability.
In real-world deployments:
- Existing landline numbers can be ported to VoIP
- Numbers are no longer tied to a physical address
- Moves, adds, and changes are dramatically simplified
I’ve personally seen businesses relocate offices without a single inbound call being missed—something that would have been painful and expensive in the PSTN era.
What Do You Actually Need to Run VoIP?
From a technical perspective, VoIP has three core requirements.
1. A Reliable Internet Connection
Latency, jitter, and packet loss matter more than raw bandwidth. A modest connection with stable performance will outperform a fast but unstable one.
Real-world rule of thumb:
- Latency < 150ms
- Jitter < 30ms
- Packet loss < 1%
2. A VoIP Service Provider
This is the platform that:
- Registers your endpoints
- Routes calls
- Handles PSTN interconnects
- Provides voicemail, call routing, IVRs, and reporting
Providers range from simple residential services to enterprise-grade cloud PBXs.
3. VoIP-Capable Endpoints
You can use:
- IP desk phones
- Softphones on PCs or mobiles
- ATAs connected to analogue phones
- Integrated VoIP routers/modems supplied by ISPs
In many homes and SMBs, the ISP-supplied router already includes VoIP ports—making the transition invisible to the end user.
VoIP in the Real World: Benefits That Actually Matter
Cost Savings (But Not Just Call Rates)
Yes, VoIP usually offers cheaper call rates—especially for international calls. But the bigger savings often come from:
- Eliminating dedicated phone lines
- Reduced hardware footprint
- Simplified moves and changes
- Less vendor dependency
For businesses, VoIP often collapses multiple systems into one: voice, conferencing, voicemail, and sometimes even messaging.
Flexibility and Mobility
VoIP decouples identity from location.
This enables:
- Work-from-anywhere setups
- Hot-desking
- Softphones on laptops and mobiles
- Disaster recovery scenarios where staff relocate instantly
During recent years, this flexibility went from “nice to have” to “business critical”.
Feature Depth That PSTN Never Had
Modern VoIP platforms typically include:
- Voicemail to email
- Call recording
- Auto attendants and IVRs
- Call analytics and reporting
- Presence and status integration
These features used to require expensive PBX add-ons. With VoIP, they’re often standard.
Multiple Calls, Same Number
Traditional landlines support one call at a time. VoIP systems:
- Allow multiple simultaneous calls
- Support hunt groups and queues
- Scale with licensing, not cabling
This is especially valuable for small businesses that want enterprise-style call handling without enterprise-style cost.
Common VoIP Pitfalls (That Marketing Brochures Ignore)
VoIP is not magic. Poor implementations fail—often loudly.
Network Quality Matters
If your network isn’t designed properly:
- Calls will drop
- Audio will distort
- Users will blame VoIP (even when the network is at fault)
QoS configuration is not optional in professional environments.
Power Dependency
Traditional phones worked during power outages. VoIP does not—unless:
- You have battery-backed networking gear
- Your ISP connection stays live
This is often overlooked in risk planning.
Security Considerations
VoIP introduces:
- SIP scanning
- Toll fraud risks
- Credential brute forcing
Proper firewalling, SIP authentication, and provider hardening are essential.
VoIP vs Traditional Telephony: The Final Verdict
From an IT perspective, VoIP wins on:
- Scalability
- Cost efficiency
- Flexibility
- Feature depth
- Integration with modern workflows
Traditional telephony is now a legacy technology—kept alive mainly for backward compatibility.
Conclusion: VoIP Is a Networking Problem Now—Not a Phone Problem
VoIP has fundamentally changed what telephony is. It’s no longer a standalone service managed by telcos; it’s an application running on your network.
For IT professionals, this means:
- Network design matters
- Monitoring matters
- QoS and security matter
Handled properly, VoIP is reliable, cost-effective, and incredibly powerful. Handled poorly, it becomes the first thing users complain about.
As legacy phone systems are decommissioned and broadband becomes ubiquitous, VoIP isn’t just beneficial—it’s inevitable.
From my early days on the helpdesk through roles as a service desk manager, systems administrator, and network engineer, I’ve spent more than 25 years in the IT world. As I transition into cyber security, my goal is to make tech a little less confusing by sharing what I’ve learned and helping others wherever I can.