Business Phone Systems: Unwrapping the World of VoIP
This year, let me give you an early Christmas present: the trade secrets of VoIP (Voice over Internet Protocol), presented in a simple way for non-technical individuals. If you run a business, this one’s for you.
The Basics of VoIP
Let’s start with a simple scenario. Years ago, we connected two phones to our network, each receiving an IP address from our router via a service called DHCP. With a bit of configuration, we successfully made a call between the two phones—no PBX server or extensions required. This experiment proved that as long as a network exists, networked devices can communicate with each other for free.
Think of a WhatsApp call: two devices (mobile phones) communicate over a vast network, enabling free calls as long as you have data services.
Introducing the PBX
Now, let’s add a PBX (Private Branch Exchange). Essentially, this is software that organizes connections and ensures calls are directed to the right device via extensions. Instead of direct device-to-device communication, each phone connects to the PBX, registers with an ID (extension), and the PBX manages the connections. Open-source projects like Asterisk and FreeSWITCH are widely used for this purpose.
We tested this by downloading free PBX software, creating extensions, and registering them on five devices. The result? All devices could call each other seamlessly.
But something was missing—a telephone line with a public number.
Enter the SIP Provider
After some research, we discovered SIP providers, who sell SIP trunks. We rented a number for R90/month, purchased airtime, and, after some trial and error, connected it to our PBX. Eureka! We had a fully functional phone system capable of making and receiving external calls over the office internet.
Challenges and Lessons Learned
While the system worked great initially, challenges soon emerged:
- Poor Call Quality: Network congestion affected call clarity.
- Ghost Calls: Phones randomly rang, displaying messages like “SIP Vicious.” Hackers target VoIP systems because of their lucrative potential.
These issues pushed us back to the drawing board, but the experience taught us valuable lessons about the importance of investing in expertise and quality infrastructure.
Key Tips for VoIP Success
Here are some areas to prioritize and pitfalls to avoid when dealing with VoIP:
1. Per-Second Billing
Choose a provider that offers per-second billing and allows you to view call detail records (CDRs) online. Transparency is critical.
2. Hidden Costs in Client Bills
Many bills obscure actual usage. Be wary of:
- Minimum Billing (e.g., R1/min): If you call a voicemail and hang up after 5 seconds, you might still be billed for a full minute. Call centers are often targeted with this practice.
- Ring Time Billing: Ringing should not be charged as part of your call.
3. Connection Charges
Some providers add unjustifiable connection fees. Avoid these where possible.
4. On-Net Calls
Internal calls within the same VoIP provider’s network (e.g., between branches or other customers) are essentially free. This principle also explains why mobile networks offer “free” SMS and minutes—they incur little to no cost for on-net communication.
5. Per-Minute Rates
VoIP pricing depends on economies of scale. Larger companies often pay 23–30c per minute, while smaller businesses might pay anywhere from 45c to R2.80 per minute. Be vigilant and negotiate better rates based on your call volume.
6. Call Recordings
Many providers overcharge for call recording services. Instead, use your PBX’s built-in recording features. If unavailable, ask an IT professional to set up port mirroring on your switch and use free recording software to capture call traffic.
The Bigger Picture: A Thought Experiment
Imagine if a progressive government established a national network of PBX servers, assigning every citizen an extension or “phone number” to enable free, on-net communication. The potential to revolutionize communication accessibility is immense.
This article only scratches the surface of the VoIP rabbit hole. My goal is to empower, encourage, and create awareness. I won’t spoil it by recommending specific providers—it’s all about recognizing when you’re being taken for a ride.
Stay safe and informed!