Replacing Asterisk with MS Communication Server [closed]

Question 1

We are examining replacing our Asterisk PBX server with MS Communications Server. We use Asterisk for the following reasons:

VoIP telephony
mass calling by streaming messages via SIP to our telecom carrier
Voice Mail
PBX
A critical feature is to have the server make 100,000+ telehone calls via SIP outbound messaging. and then delivering one pre-recorded voice message if the telephone is answered by a person and a different pre-recorded voice message if the telephone is answered by an answering machine.

We would really appreciate any practical guidance / tips for the same.

Question 2

I will do my best to answer your various points regarding OCS:

VoIP Telephony – Yes OCS can handle this, but there are a limited about of phones that support OCS directly out of the box. The nice thing about OCS is that you can manage your users through a single interface (versus having phone & network separate).
Mass calling via SIP – There is no native way to handle this with OCS. You will need some sort of SIP application server to initiate the calls.
Voice Mail – OCS does not handle voice mail. If you want to stay in the MS world – then you will need Exchange 2007 with the Unified Messaging role. I must say though, that Exchange UM is great and probably one of the best implementations I’ve seen.
PBX – All I can say is, “it depends.” OCS is going to be quite limited compared to astrisk or other dedicated PBX systems, but it does provide the basics.
100k Autodialer – This is not built in to OCS and would require an external SIP application. The main consideration with OCS would be planning for the capacity, and you can use this tool to get you started.

Answer