My organization (2 locations, one with ~100 employees and one with ~30) has been considering switching from an analog PBX phone system to a VOIP solution, but it's looking like the cost may be too high for us. A big motivation for this switch was to enhance our phone system's usability, so I'm wondering if we might be able to get some bang for our limited, nonprofit buck by deploying Exchange Unified Messaging in combination with our existing Exchange 2007 installation and existing analog PBX. So the questions I have are:
Does this even seem like a reasonable approach? The main goal would be to enable receiving voicemail and faxes within Outlook.
Can you recommend some good reference material? I've found a few things on TechNet but I'm not even sure what to search for at this point. High-level all the way down to super detailed would be welcome.
What hardware would be required? Based on my research so far, I'm thinking we'd definitely need a SIP gateway and we'd probably need another server. Can you recommend a SIP gateway for use with a Merlin Legend PBX at one location and a Definity PBX at the other?
Could this deployment be handled by a competent Exchange admin (not me), or should we figure on contracting this out?