Hello,I plan on adding UM role to an Exchange server which already holds Hub Transport and Client Access roles. Since it is quite powerful machine I do not expect any performance issues. This is a Windows 2008 Datacenter box with Exchange 2007 SP1 roles.Can someone confirm if the process is straightforward or there are special considerations I should include in planning?Thanks, MarcinMarcin Dobija | MCSE+S | MCITP:EA,SA | MCDBA | MCTS:W2k8,E2k7,SQL2005,OCS,ISA | MCBMSP:CRM4 | MS ITAC Member

Yes, you can add UM role to existing Hub/CAS server, just make sure it is not a member of NLB.Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

Hi Marcin, The Client Access server role, Hub Transport server role, Mailbox server role, and Unified Messaging server role can coexist on the same computer in any combination. You should base this decision strictly on capacity and performance planning. In order to obtain better performance and capacity, we dont recommend that install Unified Messaging role with other roles. We suggest that install Unified Messaging role on a separate computer. The following are some of the areas that you should consider and evaluate when planning for Exchange 2007 in your organization: l Your business needs for Unified Messaging l Your telephony network and your current voice mail system l Your current data network design l Your current Active Directory environment l The number of users that you will have to support l The number of Unified Messaging servers you will need l The storage requirements for users l The placement of IP gateways, telephony equipment, and Unified Messaging servers To provide a highly scalable and available solution in Exchange 2007 Unified Messaging, you must understand how the Unified Messaging components can be scaled to support your users. You must also understand how to implement a solution that will make your Unified Messaging servers highly available. I provide some articles for your references: Planning for Unified Messaging Servers http://technet.microsoft.com/en-us/library/bb125141.aspx Planning for Unified Messaging Availability and Scalability http://technet.microsoft.com/en-us/library/bb232197.aspx Regards, Rock WangRock Wang MSFT