I've recently started a little research project, through which I am hoping to figure out the best option for replacing four disparate old-skool PBX systems with a single, unified VoIP/SIP-based system. I've amassed more than a few Internet resources and have been doing research for a number of weeks, and figured someone else out there might have some ideas, as well. Plus, I need a place to catalog my thoughts and discoveries, so here we go...

I have specific needs that must be met, and probably the most complicated of them is that I have people who work in multiple locations, but who need to be logically grouped together as a team. So, there's a need for an Automated Call Distribution (ACD) capability, with full management monitoring, sign-in and sign-out, etc.

Whatever I come up with, it must be SIP-based (duh), and should integrate with/leverage the existing Windows 2003 Active Directory, as well as the communication and presence capabilities of Live Communication Server 2005 (which is highly SIP-aware, of course). A feature-rich unified messaging voice mail, FAX, etc. system is a must, with the full compliment of delivery methods. End user self-service is important - In this day and age, it's hard to imagine putting in a system that doesn't allow its users to self-manage those settings that are safe to expose.

And it needs to work. All the time. None of this random glitch, dropped call, nasty audio quality stuff. VoIP has come a long way in the past few years, and my expectations are very high. I use Vonage at home and have watched it grow from mediocre to pretty darn good over the past 18 months. But I don't want to (read: can't) do that with a business-critical PBX system, and my expectations are that the IP-PBX system will be a better experience than I've had with Vonage.

It should be enabled to integrate tightly with Microsoft Business Solutions and the Office System servers and software - like Microsoft CRM, for example. And Outlook. SharePoint integration would be a huge plus, too. Web-based chat for the customer service folks would be terrific.

What else? Well, easy to setup and maintain is a plus, and web-based administration is a no-brainer.

And it needs to be something a medium-sized business can swallow, cost-wise. The days of high-priced telephony systems and proprietary solutions are practically over, and so is my involvement with them. Good riddance.

So, here's a partial list of what I have looked at so far. I guess if it's on the list, it stands out enough in my mind enough to merit a mention:

  • Asterisk - Open source (some commercial packages of it), in use all over, has matured somewhat. I know people who have deployed it and swear by it, and others who cuss its name daily. I'll let you guess which group tends to use a strict change management process...

  • Vonexus - A commercial, Microsoft-platform-cased IP PBX system from Vonexus and parent company Interactive Intelligence, geared for and targeted at small and mid-sized businesses. The more I read about Vonexus, the more I drool. I need to contact these people and find out more. It looks almost too good to be true. We'll see what it costs.

  • Other standard players - mostly hardware specific systems from Cisco, 3Com, Avaya, etc. All are great, but all are expensive and fairly proprietary. Not sure I want to go that route.

Anyone done this before and care to share experience? Know of something I am missing out on? Let me know, especially if you're familiar with Vonexus - I'd like to speak with people who use their systems (in addition to talking to their sales people).

A few online resources that are good to watch for VoIP:

And there's many more. Send me yours and if I like 'em I'll post them, too.