I’ve written a lot about Exchange Server 2007’s unified messaging (UM) feature set. This is due to three things: the number of reader questions about it; the fact that it’s an interesting piece of technology; and my belief that better integration of voice, fax, and email offers huge potential for making individuals more productive. As Exchange 2007 becomes more widely adopted, the market for devices and services that work with it is changing rapidly, so this week I'll cover some of the adaptations and changes that are taking place.

First, the number of software-based IP PBX systems that work with Exchange has grown. I’ve already written about Asterisk, the Linux-based Session Initiation Protocol (SIP) over UDP system that doesn’t work with Exchange 2007 ("Getting Exchange and Live Communications Server Together on the PBX," July 6, 2006). However, a couple of intrepid people have figured out how to use SIP Express Router, a Linux-based freeware product, to make the two work together; check out this blog for configuration information.

Unless you’re already using Asterisk, or have a hankering for tinkering, you might want to consider some of the growing crop of software PBX systems that run on Windows. You might have seen ads for 3CX's software PBX, but there are other systems out there. As far as I can tell, 3CX doesn’t yet support Exchange 2007, but I just learned—courtesy of UPDATE reader Charley Lanusse—that pbxnsip's PBX system supports Exchange 2007, although I haven’t tested it yet. There are probably other Windows-based systems that work with Exchange 2007, too, so if you’ve found one, please let me know! Of course, it’s worth pointing out that Microsoft doesn’t officially support any software-based PBX for use with Exchange 2007, so you’ll have to be fairly knowledgeable to troubleshoot any problems you run across.

Second, the number of hardware PBX systems that support direct interoperability with Exchange 2007 is also growing. Almost all hardware PBX vendors sell voicemail capability, either as stand-alone systems or as a PBX feature. When Exchange 2007 was first introduced, some vendors were slow to announce support for it; my guess is that they were afraid Exchange 2007 sales would cut into their voicemail sales.

However, this fear appears to have given way to a perfectly natural desire to grab as much Exchange 2007 business as possible. Mitel Networks announced on March 21 that it's now shipping updated firmware for its 3300 series of IP communications controllers that allows direct communication with Exchange 2007. This is big news for two reasons. First, it removes the requirement for an additional, expensive, hard-to-configure gateway. Second, it removes the uncertainty about whether PBX vendors are likely to support direct interoperability. Mitel’s move is a good step for everyone: it helps Mitel sell 3300s; it helps Microsoft further establish Exchange 2007 as a solid UM choice; and it helps administrators deploy Exchange 2007 UM without unnecessary complexity and expense. I’m looking forward to seeing which other PBX vendors will provide direct interoperability now that Mitel has broken the ice.

Of course, one unanswered question is exactly how Microsoft Office Communications Server 2007 will work with Exchange 2007. Microsoft has been mum on the details, but look for more information here after the company releases a public beta of Communications Server 2007 later this spring.