There are evolutions, and then there are revolutions. The new PIAF5 powered by 3CX v15.5 is revolutionary on so many levels: price, feature set, flexibility, stability, and security for openers. For Nerd Vittles readers that want a free PBX1 for your home or small business, there’s a revolutionary bonus. Starting today, you can download a one-year license for an 8 simultaneous call, 10+ extension, unlimited trunks edition of 3CX v15.5 at zero cost!2

Unlimited Trunks, 10+ Extensions, 8 Simultaneous Calls… Free!

The 3CX development team not only heard but also heeded our suggestion to expand the number of trunks in the free edition by removing the limitation entirely. With small businesses and home users, the number of times you ever will need to make more than 8 simultaneous calls is probably NEVER. Based upon industry standards, this 8-call, 10-extension PBX with unlimited trunks can easily support up to 10 people so it’s perfect for home use or a SOHO business. And, when your business grows, upgrading to a larger PBX is inexpensive and a one-minute key swap.

Cost savings, of course, are only part of the VoIP story. There’s a reason 3CX’s business is growing geometrically while others struggle. 3CX provides an unmatched feature set that’s easy to use and deploy. Version 15.5 brings the Linux platform to full parity with 3CX’s previous Windows editions plus all-new 3CX clients for every desktop and mobile device. There’s also an awesome new web client providing users easy access to all key 3CX features without installing any software. Desktop call control including Click2Call now is based on uaCSTA technology. Snom and Yealink phones as well as 3CX clients can be controlled from any desktop client even if your phone system is running in the cloud, $3.49/mo. at OVH.

With 3CX’s powerful client software, your office and your PBX can literally be anywhere. Your desktop is always as close as your smartphone or the nearest WiFi hotspot. That’s what unified communications is all about. And, should you ever need support, 3CX has offices in the U.S., U.K., Germany, Hong Kong, South Africa, Russia and Australia. Review the 3CX feature comparison chart3 and you can judge the feature set for yourself. Whether you’re a homebody or world traveler, we think you’ll agree that 3CX’s new free edition for Nerd Vittles readers offers everything that a home or SOHO user will ever need in a PBX.

Getting Started with PIAF5 on Dedicated Hardware or a Virtual Machine. If your platform supports ISO installs, here are the simple steps to get PIAF5 up and running. First, download the PIAF5 ISO and burn it to a CD or thumb drive. Second, obtain a free PIAF5 license key for 3CX. Next, boot your server from the ISO image and walk through the Debian setup process. We recommend 2GB of RAM and a 20GB drive for PIAF5, but it will run on even a minimal CloudAtCost server. When the install is finished, make note of the IP address to access with a web browser to complete the setup. Enter your 3CX license key when prompted. Set up one or more SIP trunks with inbound and outbound call routes. Once you have the ISO and your license key in hand, the installation procedure takes less than 10 minutes.

Getting Started with PIAF5 in the Cloud. Begin by setting up a 64-bit Debian 9 platform. Obtain a free Nerd Vittles license key for 3CX. Once your Debian install is finished, log in as root using SSH or Putty and issue these commands. NOTE: What appears as the third line below needs to be added to line #2!

wget -O- | apt-key add -
echo "deb stretch main" | tee /etc/apt/sources.list.d/3cxpbx.list
apt-get update
apt-get install libcurl3=7.38.0-4+deb8u5
apt-get install 3cxpbx

When the initial setup finishes, choose the Web Interface Wizard and complete the install using your favorite web browser. Enter your 3CX license key when prompted. Set up one or more SIP trunks with inbound and outbound call routes. Done.

Configuring Gmail as SMTP RelayHost for 3CX. 3CX has a detailed tutorial explaining how to set up your Gmail account as the SMTP relay host for 3CX. Be advised that there is one additional step before Google will authorize access from an IP address it doesn’t already have for your GMail account. In addition to Enabling Less Secure Apps (as covered in the 3CX tutorial), you also will need to activate the Google Reset Procedure while logged into your Gmail account. Otherwise, Google will block access. Once you have configured Gmail as your relay host and performed the two enabling steps above, immediately test email delivery within the 3CX GUI while Google security is relaxed: Settings → Email → TEST.

Free Calling in the U.S. and Canada with PIAF5. We know our more frugal U.S. residents are wondering if there’s a way to make free calls even with 3CX. You didn’t really think there would be a release of PBX in a Flash without Google Voice support, did you? It’s easy using the Simonics SIP to Google Voice gateway service. Setup time is about a minute, and the one-time cost is $4.99 using this Nerd Vittles link. Setup instructions for the 3CX side are straight-forward as well, and we’ve documented the procedure on the PIAF Forum.

Free Calling Worldwide with SIP URIs. There’s another free calling option as well. PIAF5 and 3CX support worldwide SIP URI calling at no cost. As part of the PIAF5 install procedure, 3CX registers an FQDN for you with one of the 3CX domains if you indicate that your server has a dynamic IP address. Unless you really know what you’re doing with DNS, it’s a good idea to tell 3CX you have a dynamic IP address whether you do or not. Here’s why. Once you have an assigned FQDN in the 3CX universe, one very slick feature is the ease with which you can publish a SIP URI address for any or all of your 3CX extensions thereby allowing PIAF5 users to receive calls from any SIP client worldwide at no cost. Setup takes less than a minute. It’s as easy as 1-2-3. Here’s how:

1. Login to the 3CX GUI and go to Settings → Network → FQDN. Tick "Allow calls from/to external SIP URIs" and make note of your FQDN, e.g. Click OK.

2. For an extension to enable (e.g. 001), go to Extensions → Edit 001 → Options → SIP ID and create any desired SIP URI alias for this extension, e.g. billybob. Click OK.

3. If your PBX is sitting behind a router/firewall, be sure the following UDP ports are forwarded to the local IP address of your PBX: 5001, 5060, 5090, and 9000-9255.

4. Anyone with a SIP client anywhere worldwide can now call extension 001 using SIP URI:

Originally published: Wednesday, June 7, 2017  Updated: Wednesday, December 27, 2017

Need help with 3CX or VoIP? Visit the PBX in a Flash Forum.


Special Thanks to Our Generous Sponsors

FULL DISCLOSURE: 3CX, RentPBX, Amazon, Vitelity, DigitalOcean, Vultr and others provide financial support to Nerd Vittles and our open source projects through advertising or referral revenue. We’ve chosen these providers not the other way around. Our decisions were based upon their corporate reputation and the quality of their offerings and their pricing. Our technology recommendations are reached independently of financial considerations except in situations in which comparable products at comparable pricing are available from multiple sources. In this limited case, we support our sponsors because our sponsors support us.

Awesome Vitelity Special. Vitelity has generously offered a terrific discount for Nerd Vittles readers. You now can get an almost half-price DID from our special Vitelity sign-up link. If you’re seeking the best flexibility in choosing an area code and phone number plus the lowest entry level pricing plus high quality calls, then Vitelity is the hands-down winner. Vitelity provides Tier A DID inbound service in over 3,000 rate centers throughout the US and Canada. When you use our special link to sign up, Nerd Vittles gets a few shekels down the road to support our open source development efforts while you get an incredible signup deal as well. The going rate for Vitelity’s DID service is $7.95 a month which includes up to 4,000 incoming minutes on two simultaneous channels with terminations priced at 1.45¢ per minute. Not any more! For our users, here’s a deal you can’t (and shouldn’t) refuse! Sign up now, and you can purchase a Tier A DID with unlimited incoming calls and four simultaneous channels for just $3.99 a month. To check availability of local numbers and tiers of service from Vitelity, click here. NOTE: You can only use the Nerd Vittles sign-up link to order your DIDs, or you won’t get the special pricing! Vitelity’s rate is just 1.44¢ per minute for outbound calls in the U.S. There is a $35 prepay when you sign up. This covers future usage. Any balance is refundable if you decide to discontinue service with Vitelity.

​​3CX is a software PBX that’s easy to install & manage. It includes integrated softphones, WebRTC conferencing and essential add-ons out of the box, at no additional cost. Try the free edition at Better yet, download the PIAF5 ISO powered by 3CX. Free version includes support for 8 simultaneous calls with a SIP trunk.

  • Run on Premise or in the Cloud, on Windows and now on Linux
  • Softphones for iOS, Android, Win & Mac
  • Easy install, backup & restore, version upgrades
  • Automatically configures IP Phones, SIP Trunks & Gateways

  • RentPBX, a long-time partner and supporter of PIAF project, is offering generous discounts for Nerd Vittles readers. For all of your Incredible PBX hosting needs, sign up at and use code NOGOTCHAS to get the special pricing. The code will lower the price to $14.99/month, originally $24.99/month. It’s less than 50¢/day.

    Some Recent Nerd Vittles Articles of Interest…

    Be Sociable, Share!

    1. Don’t confuse 3CX’s free PBX with Sangoma’s FreePBX® GUI. The former is a truly free PBX provided by a well-respected developer of commercial PBXs used by many of the world’s largest companies including Boeing, McDonalds, Hugo Boss, Ramada Plaza Antwerp, Harley Davidson, Wilson Sporting Goods, and Pepsi. The latter is a code generator for Asterisk® that commingles free components with commercial NagWare, each of which requires payment of separate licensing and maintenance fees before and during future use. []
    2. Software updates and FQDN support for your PBX are free for the first year. []
    3. Ignore the feature set described for the free version. The Nerd Vittles edition is a very different beast. 😉 []

    This article has 7 comments

    1. OK, so I’m a bit confused by the available features. Is this just the "free" version but with call/extension/trunk changes listed at the top? If so, then there are lots of other features we can’t use, but are available in older versions of PIAF….so I won’t be getting too excited, yet. 🙂

      [WM: I’m not going to spoil the surprise for you. This version was built exclusively for Nerd Vittles followers. Obtain a new license key and take it for a spin. I think you will be pleasantly surprised.]

    2. I was hoping that the sentence "And, when your business grows, upgrading to a larger PBX is inexpensive and a one-minute key swap" also meant that I could apply the new (free) key to an existing 1-trunk 8-call server which is already upgraded to 15.5.5. But I can’t find any way on the GUI and googling finds a post which says not possible and a complete re-install is required.

      [WM: Correct. Upgrades are only available to move to a more robust commercial version. This new free version was produced exclusively for Nerd Vittles so I’m afraid you can’t switch from a previous free version to this one. It’s worth the effort, however. 🙂 ]

    3. Well, this sounds a lot more reasonable / usable than the previous free version. It was just too limited to even have a look at it. Now with more than one trunk possible, this makes more sense. For smaller offices and at home, most people probably won’t run into the limits of 10 extensions and 4 concurrent calls. Maybe I’ll give it a look now. But I am still leaning more towards Wazo though.

    4. "[O]btain a free Nerd Vittles license key for 3CX."

      How is this a ‘Nerd Vittles’ license? It takes you to [the 3CX site].

      Nothing special about that.

      [WM: We beg to differ. Try finding it without the Nerd Vittles link. 😉 ]

    5. Is there a possibility of a 3CX RasPi version in the future??

    6. I came to look for an upgrade to a long running Incredible PBX installation. So sad to see you sold out to 3CX. I guess I have to look for a different option to stay with Asterisk.

      [WM: Huh? Not sure how you missed it, but there are six open source, GPL-compliant Incredible PBX solutions plastered on colorful buttons in the top right column of every Nerd Vittles article: Incredible PBX for Wazo, Incredible PBX ISO, Incredible PBX for CentOS, Incredible PBX for Ubuntu, Incredible PBX for the Raspberry Pi, and Incredible PBX for Issabel.]

      Incredible PBX Alternatives

    7. I have been using Incredible PBX for 5 years now. It’s one of the best for small business. I cant thank WM enough for the free 3CX version for PIAF5…..awesome….. I think people need to take a little time to research, read, and use it before jumping to write a comment. THANKS AGAIN WM.