Achieving Exchange 2007 Unified Messaging Connectivity

One of Exchange Server 2007's most significant new features is Unified Messaging. In short, Exchange 2007 can supplant your organization's existing voicemail system and provide your users with all of the same services... and then some. In order to provide these services, your Exchange 2007 server must integrate with your PBX. Exchange 2007's native unified messaging communication protocols are Session Initiation Protocol (SIP) and Realtime Transport Protocol (RTP). Since not all PBXs are SIP-enabled, there are a couple of ways to go about achieving connectivity between PBXs and Exchange 2007 servers.

IP-enable the PBX

Depending on the PBX, it may be possible to upgrade the device to natively support SIP. In my organization's case, we have a Nortel Meridian 1 switch and a separate voicemail system that has reached end-of-life and it no longer supported. This summer, we are upgrading the switch to Nortel's software version 5, which will SIP-enable (VoIP-enable) the PBX and allow it to communicate directly with our Exchange organization. Our Exchange organization is currently running only Exchange 2003, but will also be upgraded.

Install an IP/VoIP gateway

In many cases, it's simply not feasible to upgrade a PBX. PBX upgrades can be costly and complex and not all units can be upgraded to support SIP/VoIP. As such, Exchange 2007 also supports gateway devices that handle the translation between many PBX models and SIP. One such vendor, Dialogic, sells a wide variety of devices designed to support many different PBXs.

For more information on a gateway that might work in your environment, visit Microsoft's Telephony Advisor page.  


Since 1994, Scott Lowe has been providing technology solutions to a variety of organizations. After spending 10 years in multiple CIO roles, Scott is now an independent consultant, blogger, author, owner of The 1610 Group, and a Senior IT Executive w...


We are in the same boat! We have a 7 year old Repartee' still running on a OS2 box that we need to replace before it fails. We too plan to upgrade to Rls 5.0 this summer and move to Exchange 2007 this winter after 5.5 comes out from Nortel and SP1 from MS. This will be an incredible change for our organization (1300 staff) so communication to them is going to be key. I just hope the Nortel/Microsoft alliance is strong and they are both on the same page!


Our voicemail system is an old computer with MS-DOS and the almighty turbo button. 66MHz of raw power! Just a month ago the PSU bit the big one so now I've rig and equally POS PSU to run the system. I don't know why, but I keep old PSUs so lucky me. One day we'll buy a new system... when retina scans are the required Windows authentication for a $500 pre-built home user computer...


I was in a similar situation with our x386 SX Avaya Audix system- the tape backup drive ate itself, and the vm software would sporadically just *fail* to deliver messages. When dealing with various court and social service agencies, that's a Bad Thing(tm)! As prone to happen in the non-profit world, the company bought the system new, and never- NEVER! paid for support or software upgrades on it. I came into this disaster, and got to support the dang thing for 8 years (without software upgrades). That's the sucky part of being an NPO. So, when the thing was *really* getting ready to dump for the last time, I found a Cisco grant program, applied, and received one of the largest product donations they've ever given! $155,000 worth of switching, CallManager, Unity Connections, voice router, analog gateway... We just had to pay the installation. Now I have a GREAT phone system! THAT is the good part of being an NPO! (now, if I could just do something about the pay, and me being the *entire* department...)

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