Analog to VoIP

Micah Cerasani

Mar 10, 2024 — 4 min read

Well, it’s March again, and that means at least one thing: it’s time to revisit my phone situation. For anyone who doesn’t know, life abroad comes with a slew of challenges, not least among them being telephony.

It was two years ago when I came across an enterprise solution that knocked off my socks. I was introduced to the world of PBX, SIP, and SPTN. If all those acronyms are too much, you are in for a read. The shortest version of the story is that through the magic of the aforementioned alphabet soup, phone calls and text messages using a local US-based (but not necessarily, as we will discover later) phone number are simple and cheap. Say goodbye to your calling cards, if you are old enough to remember those things.

Let’s define a few things:

PBX

A PBX is like a private telephone network used within a company or organization. It allows internal communication between employees as well as connection to external phone lines. Think of it as a sophisticated telephone system that manages calls within a business, offering features such as call forwarding, voicemail, and conferencing. Some will even allow you to send and receive text messages and host video chats.

SIP

SIP is a protocol that enables voice and video calls over the internet and is often associated with VoIP (Voice over Internet Protocol) services. SIP allows different devices and networks to communicate seamlessly, enabling services like internet telephony and video conferencing. It is responsible for setting up, maintaining, and tearing down connections between participants on a call. SIP sounds complicated; I am over complicating it in my definition in efforts to feel smart.

One of the neatest things about SIP trunks is the availability to bridge between your PBX and the PSTN of just about any given country. You just find a SIP provider with favorable rates in the calling region of your choice, subscribe (get a phone number) and you are good to go.

PSTN

PSTN refers to the traditional telephone system that most people are familiar with. It's the global network of copper wires, fiber-optic cables, cellular networks, and satellites that enable landline and mobile phone communication. In essence, it's the backbone of global telephone communication, connecting callers worldwide.

*note* Depending on where in the world you are reading this post from, your country may already be on the path to phasing out the PSTN entirely in favor of VoIP (voice over internet protocol) technology. As PSTN infrastructure ages, there are fewer and fewer professionals around to service and maintain the analogue phone network. Moreover there has been an industry-wide push to see adoption of VoIP technology slated globally for as soon as 2030 and earlier in some regions (such as the UK, 2025).

What does that mean to you as an end user? Likely nothing. Calls and texts will still work as before—they will just connect over the internet instead of the PSTN. It may translate into savings, if you are the one setting up and maintaining the services, though. Then again, it may not. Fear not; as VoIP will replace PSTN, so also did PSTN supplant telegraphs.

So, now that we have all that out of the way,

let’s get back to my case of these technologies and the motivation for writing this particular piece in the first place.

I imagine you either want to get ahead of the curve and set up your own VoIP stack, or you are just curious what has been keeping my occupied of late. To be honest, tuning my setup hasn’t been even remotely as time consuming as writing up this post to accompany it. I was left speechless at the speed of deployment after said was done, and a brand-spanking-nagelneu PBX was successfully up and running in the cloud. Here is a brief overview of what to do. Don’t worry, you‘ll be home in time for supper. This won’t take long at all.

Before you get started, you will need a few things: first, you will need a PBX. I use 3CX, because it has great cross-platform support. Second, you need a SIP provider. Telnyx is my provider of choice, because they allow a pay-as-you-go billing model. And last, you will need a place to run your PBX server.

That said, before you really get started, if you are going to follow along, you will need to set up an account with 3CX and AWS. I will not be going through the setup of the SIP trunk, because you may find a better deal in your region with a different provider. Where I could give you a general overview of the SIP trunk setup, it’s best to follow the documentation from your provider.

There are a number of different locations to run a PBX: you can pay a company to host it for you, you can host it on premise, or you can spin it up in a cloud provider’s environment (after all, cloud is little more than just someone else’s computer that you pay for the privilege of using).

I chose Amazon Web Services (AWS) as my cloud provider. It came down to the sheer quantity of relative, in-depth documentation. That documentation was well-needed when I first set up the PBX. And joining AWS meant I got a year’s worth of free-tier resources to tinker with for free. Luckily enough for me, the PBX is so light on resources, I was able to run it non-stop for about $0.80 per month.

Here is link to a tutorial on how the setup process looked when I first set things up.

That was a while ago—2 years. And a lot has happened in the world of computers since then. If you took the time to watch even half of Chuck’s tutorial, your head may be rightly spinning. But 3CX have made cloud deployment so much easier since then. I think I had the whole thing set up in about 15 or 20 clicks—you count and see and see how far off my click count was.

Happy networking! Happy calling!