Need suggestions on OCS with existing analog phone lines

We are considering switching to Office Communications Server 2007 as a solution for internal VOIP, IM, and Presence.
However, we'd also like it to integrate with our existing analog phone lines, as we want to keep our main incoming phone line and fax.
Does anyone know where I can get info, or make suggestions, about finding the proper hardware and software to put this in place?
I would assume we need a analog adapter for the 4 incoming phone lines.
Thanks in advance for the help.
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feptiasChief DudeCommented:
First, I can't help a lot with this because Microsoft were somewhat unhelpful when I tried to get documentation last year about interoperability between existing PBX systems and OCS. I think they like you to go to one of their approved UC partners such as AudioCodes:

However, searching the web throws up some info about integration of asterisk and OCS. Asterisk is an open source PBX that runs on Linux platforms and it supports SIP, analogue (FXS and FXO) etc. A word of caution, Microsoft OCS uses TCP, not UDP, for SIP connections. Any off-the-shelf analogue-to-SIP adaptor will almost certainly be UDP only.

Yes, you can do this. At this moment I believe you will need a 2nd server as a mediation server to go between OCS and the SIP/PSTN Gateway. I have been researching and understand that you can go direct now. (i'm checking one server possibility)

There are several phone handsets becoming available: Polycom has one. SNOM recently released an OCS edition of their SNOM 3XX handset that are a very reasonable price.


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thecomputerdocsAuthor Commented:
Isn't there a D/A card that can be put in the OCS server?
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