Inevitably, when talking about free, software-based phone systems, the extremely popular Linux-based Asterisk IP PBX will come up as an option. Should we use Asterisk or a Windows-based solution? Let's look at some of the strong points of each.
It has been around for a while and has a lot of installs
There are a lot of add-on products surrounding it
Asterisk installs on a free operating system—Linux
Asterisk Free version has features comparable to 3CX Commercial edition
The following are the advantages of Windows 3CX:
Large number of people already familiar with Windows server administration
Easier to integrate with existing Windows networks
Easier to integrate with Microsoft Exchange
Supports SIP forking (allows two or more devices to be registered to the same extension)
I started out in the IP PBX world using Asterisk@Home (now Trixbox). Because of my unfamiliarity with Linux, I spent a lot of time trying to figure out how to perform simple operating system tasks. After working with Asterisk for quite a while, it dawned on me that what I really wanted was a free (or low cost) phone system with integration capabilities, one that worked reliably, and one that I could call for support in rare instances when something didn't work right.
At one point, getting commercial support for Asterisk was an issue, but now commercial support options are available. There still may be an issue to get a vendor who will give a list of hardware that they will support along with Asterisk. The "last straw" that made us switch to a Windows-based phone system was when we had an issue with Asterisk. We called several vendors and asked them what hardware should we get to be in a supportable condition, and no vendor could list it for us. However, once again, I believe support for Asterisk is no longer an issue.
I think the decision between 3CX and Asterisk is one that each administrator needs to make. However, for many small businesses, a Windows solution makes sense.
One thing that makes 3CX very attractive to hobbyists, small businesses, and IT managers is its cost of entrance—free! The 3CX community has grown quite rapidly because of the free edition of the 3CX Phone System. It can be a little confusing to a new 3CX administrator about what is included in both the Free and Commercial editions, but the chart provided by 3CX at the following URL helps clarify a lot of questions that come up. The latest feature comparison chart is available at http://www.3cx.com/phone-system/edition-comparison.html.