Cisco Systems OL-14619-01 manual Exchange Considerations All Versions

Chapter 4 Designing a Cisco Unity System with Exchange as the Message Store

Considerations for Customer-Provided Infrastructure

Exchange Considerations (All Versions)

Note the following Exchange considerations when a Cisco Unity implementation will use customer-provided Exchange infrastructure:

•When Cisco Unity is installed, the installer chooses a partner Exchange server, which is the home of several default Cisco Unity mailboxes, including:

–The Cisco Unity system mailbox (alias: Unity_<ServerName>), which is the mailbox that originates voice messages from outside callers. (Voice messages from Cisco Unity subscribers originate from the mailbox of the caller.) Each Cisco Unity server must have its own system mailbox.

–The mailbox from which broadcast messages are sent.

–If Cisco Unity is interoperating with other voice messaging systems, the mailboxes that send voice messages to and receiver voice messages from the other voice messaging systems.

The partner Exchange server can be running Exchange 2007, Exchange 2003, or Exchange 2000, and it can be either a clustered or non-clustered Exchange server.

Because of the importance of the partner Exchange server in a Cisco Unity installation, the server should be selected primarily on the basis of availability and secondarily on the basis of performance.

•Exchange performance is critical to Cisco Unity performance. To ensure that Exchange performance will not adversely affect Cisco Unity, we recommend that customers assess the performance of their Exchange infrastructure before installing Cisco Unity. For example, the Microsoft TechNet article Exchange Server 2003: Ruling Out Disk-Bound Problems (http://technet.microsoft.com/en-us/library/aa997558.aspx) can provide useful guidance.

•Exchange servers must meet Microsoft requirements, including the maximum number of users per server, the proper amount of memory, the proper processors and processor speed, hard disks that can meet disk-access response times, and placement of data files and transaction log files.

Cisco Unity cannot support Exchange servers that have performance bottlenecks such as slow hard drives or insufficient memory. For example, if slow hard drives or the lack of a dedicated mirror for transaction logs cause delays in recording log transactions, MAPI access (which is used by Microsoft Outlook, Exchange, and Cisco Unity to access Exchange) will be temporarily suspended until the transaction buffers can be cleared to a certain level. This can substantially delay phone access to Cisco Unity.

•The Cisco Unity Voice Connector for Microsoft Exchange, which is required for communicating with another voice-messaging system by using AMIS, the Cisco Unity Bridge, or VPIM, must be installed on the partner Exchange server. The Voice Connector can also, optionally, be installed on one or more other Exchange 2000 or Exchange 2003 servers to optimize message routing via Exchange’s native, cost-based routing. (The Voice Connector cannot be installed on an Exchange 2007 server.)

•For information on the impact of audio codecs on Exchange, see the “Audio Codecs” section on page 3-5.

•In a Voice Messaging configuration, to prevent the message store from filling the hard disk, some customers configure storage limits in Exchange, and use Cisco Unity Message Store Manager to delete old messages. For example, messages older than 30 days might be moved to the deleted-messages folder, and messages older than 60 days might be purged. For more information on Message Store Manager, see the Message Store Manager Help at http://ciscounitytools.com/HelpFiles/MSM/MSMConsoleHelp_ENU.htm.

Design Guide for Cisco Unity Release 5.x

OL-14619-01 4-7