Anyone attempt to integration Exchange 2013 UM with their 3300? In our test environment everything seems to work more or less as it does with Exchange 2010 except now with multiple possible UM servers (mailbox role now) the system breaks down. What doesn't seem to work properly is the ability to dial the UM subscriber access number/Outlook Voice Access (OVA) number from an extension (Mitel phone or outside) that is not associated with a UM mailbox. If you dial the OVA from such a location the voicemail autoattendant asks for your extension to access your mailbox. If the mailbox is in a database that is not actively mounted on the server that answered the call, it performs a SIP REFER to the 3300 telling it to call the other mailbox server. However, UM specifies this using the originally dialed OVA number which is what you expect. Since routing out of the 3300 is done by ARS digits dialed, it sees the number part of the URI and ignores the destination and places the call right back to the original UM server. For example, consider two Exchange servers both running Client Access Server and Mailbox server roles (EX1.local.com and EX2.local.com). OVA number is 5950. ARS Digits Dialed is set to send 5950 down the SIP trunk to EX1. So, when the initial INVITE hits Exchange you see the invite as 5950@EX1.local.com. When prompted to enter mailbox extension you do. If that mailbox is in a database mouted on EX2 then EX1 sends a SIP REFER back the header information like:
REFER-TO: <sip:5950@ex2.local.com:5062;transport=Tcp>
REFERRED-BY: <sip:ex1.local.com;c=ms-ova-data;v=1.0;Extension=5000>
What the 3300 does is ignore the ex2.local.com part of the refer and just dials 5950 again which it forces to be routed to ex1.local.com. Consequently, it also drops the Extension information in the REFERRED-BY.
Anyone have any ideas on how to get this to work?
