Open source PBXes: free flexibility

Asterisk worked fine, but consider the amount of open source familiarity necessary to reach its full potential and integrate all the pieces you might want in an enterprise deployment. There are plenty of options to add more bells, whistles, and interfaces, but you’ll need to know what you’re doing in order to implement them.

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SIPxchange V.2.4

Unlike Asterisk’s purely open source approach, Pingtel’s SIPxchange has a more commercial flavor. It’s still an open source product — the base PBX, sipX, can be downloaded from the SIPfoundry Web site for free — but if you pay Pingtel’s modest price, you get additional support, plus plug-ins and tools such as media gateway services.

Most companies will opt for a dual-processor platform with power and disk redundancy for their IP PBX, but even here, the cost of moving to SIPxchange is very low compared to other commercial competitors we reviewed.

Pingtel’s distribution of SIPxchange runs on Red Hat Linux and is compatible with most commercially available SIP-based IP phones. The 2.4 distribution includes Web-based graphical management interfaces, an automated attendant, and voice mail, among other features.

I tested the Pingtel software on a 1U server provided by the company. Most of the phones we used were Cisco 7912, 7940, and 7960 SIP, but we also included Pingtel’s sipX softphone, which could be useful for traveling employees. All phones were connected to an Ethernet switch on a dedicated, closed network.

Initial installation of the sipX and Pingtel software required a considerable amount of manual intervention. Luckily, after the software was installed, the graphical interfaces eased the configuration burden, and there are scripts for many tasks.

However, adding phones to the network isn’t always easy. You have to enter each phone’s MAC (media access control) address individually before you can use the phone. This means either typing that address in or using a bar-code scanner, because the Pingtel software has no way to query the phones for this information. Plus, you’ll have to repeat this process each time you add a new phone to the network. Unless you have a very small phone network, this could rapidly become a burden on the IT staff.

On the other hand, once you add the phones, managing them is made easier by a well-designed interface that allows you to control the phones’ features and functions. You can, for example, assign specific functions to specific buttons on the phones cen-trally, and Pingtel includes graphical interfaces for user inboxes and for control of voice mail.

After the initial setup, I found SIPxchange to be very effective and easy to use. The user interfaces are convenient, and the graphical management interfaces are well-designed and intuitive, so you won’t have to hire multiple sipX experts to run your phone system (although you will still need at least one). This is a solution that should fit in well with your enterprise, especially if you have experience with commercial distributions of open source software.

Ringing Up Open Source

Basic call services, such as voice mail, transfer, and call waiting, can all be done with any phone supported by these products. Advanced features, such as outboard conferencing, depend on what the administrator wants to allow, and, of course, what the phone will support.

Both of these phone systems seem to have a nearly limitless ability to be expanded and customized, no matter what it is you wish to accomplish. That’s the beauty of open source software, and it certainly holds true with PBXes.

Asterisk, of course, is just that — open source. It runs on a variety of platforms and supports several types of digital communications. Although it includes fewer management features as standard equipment, similar features are available from the open source community. Adding them, or almost anything else, is reasonably easy to accomplish if you’re familiar with the workings of open source technology.

With Pingtel’s version of sipX, you get more but you also pay more. It’s easier to manage, thanks to the included graphical interfaces, so you’ll need to spend less time training staff. If you’re looking for just a PBX, then Pingtel is well worth the modest cost. If you’re looking for something more, you’re going to need to look to the open source community and add it yourself — and it will only cost you a bit of time and installation effort.