I had this question from a university in the rocky mountain range. With Exchange Server 2007 unified messaging, the UM server can directly detect a fax tone using the T.38 FOIP (Fax Over IP) standard and route inbound faxes to an extension. It does not provide the ability to send faxes outbound. For outbound faxing, it is required to use a 3rd party Fax software product.
How can I configure the fax extension?
The fax extension can either be a dedicated fax mailbox, the same extension as the users mailbox or a separate extension paired to the user's mailbox.
What does the inbound fax flow look like?:
The inbound fax hits the IPPBX or PBX and the signal is translated to T.38 (FOIP) directly or through the SIP GW. The Exchange UM server is listening for the T.38 tone. Once the UM server detects the T.38 tone, the fax is converted to .TIF on the UM server. Next, the UM server performs an AD lookup for the extension, routes the fax message to the Hub Transport which routes it to the correct the mailbox server.
Does this require a fax card to work?
There is no additional fax HW required for this to work.
How does inbound fax work if I am voice enabled with OCS?
The OCS Mediation Server currently does not understand the T.38 FOIP standard therefore you must create a separate extension and route fax extensions directly to the UM server versus through the Mediation Server. Click here for more information.
What does the fax look like?
Similar to a voicemail, the fax arrives as a .TIF attachment in your Outlook, OWA or Activesync mobile device inbox. Here is a sample fax in Outlook:
Does this require Windows Server 2008 fax services and do they integrate?
No, it does not require Windows Server 2008 fax services and they are not integrated at this time. For more on Windows Server 2008 fax services see here.