Yes, you heard correctly. You can replace your existing PBX system today with Microsoft’s Office Communications Server 2007 R2 platform. The trick is in using SIP Trunking, not existing old school telephony/TDM communication for your voice platform. Here, I’ll give you a visual:
1. Your typical enterprise voice platform consists of a PBX (Private Branch eXchange) system that controls and homes all of your user accounts, voice mail, inter-company and branch office calls, as well as provides you with outside communication access by pressing the 9 button on your dial pad.
2. Today we have a next generation voice solution which is called SIP Trunking. Forget Vonage, Skype, and all of the consumer VoIP crap that’s out there. I’m talking about enterprise-grade VoIP/SIP communication. SIP provides not only voice, but also data and video, so you now replace all of the archaic phone lines with hardcore SIP that provides you with HD voice audio and also provides you with data and video communication for even cooler stuff like web conferencing and Telepresence. These SIP Trunks are provided by major voice carriers like Sprint, AT&T, Vodafone, Personal, etc. With each trunk you also receive a series of voice channels that supports a number of incoming and outgoing current calls. The carrier provides the connection to the outside world/PSTN just like your PBX did by pressing 9 on your dial pad. Instead of a phone number like you had in the past, you are now contacted by using a Direct Inward Dialing (DID) number through your ITSP SIP Trunking provider. With a Direct SIP communication solution and the Microsoft Unified Communications platform, you now have the ability to not only replace your voice system, but also enable other features such as single number reach and fixed mobile converged device solutions so that you have the ability to communicate with any device or application for your communication needs changing the way you are contacted from a number to your actual identity and availability.
Add-on Unified Messaging through Microsoft Exchange Server, and you can see voicemail and missed call notifications like you used to see on your phone, now through Microsoft Office Outlook, Office Communicator, and on mobile devices as well as have access to the entire system outside the firewall without any VPN required.
Now that’s freaking cool. Oh, and by the way, this actually saves you money! So for those of you who were wondering if you had to wait until the next OCS release for this capability, it's here now. While OCS currently does not support branch office capability, SIP Trunking fills the void to provide a PBX replacement today through the power of enterprise voice. For more information on SIP Trunking packages, just run a simple search or contact any main voice carrier. This is the future my friends.