Exchange Server 2010 (SP1) Unified Messaging (UM) Integration with PBX – Changes from Exchange Server 2007
Unified Messaging (UM) requires that you integrate Microsoft Exchange Server 2010 with the existing telephony system for your organization. A successful deployment requires you to make a careful analysis of your telephony infrastructure.
Although Exchange Server 2007 and Exchange Server 2010 Unified Messaging have almost identical architecture Yet IP-PBX supported integration has changed with Exchange Server 2010/Exchange Server 2010 SP1. For Example Exchange Server 2010 (SP1) only support Cisco IP BPX with Call manager 5.0, 5.1, 6.0 and 7 as direct SIP Integration (without use of IP Gateway).
The article below explains in details the different Integration types between Exchange Server 2010 (SP1) Unified Messaging and Telephony BPX Infrastructure :