Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2007-10-19

There are many performance counters that can be used to maintain and troubleshoot a computer that is running Microsoft Exchange Server 2007.

Unified Messaging performance counters are used to measure quantities of information or data for Unified Messaging based on the number, size, duration, and rate of data that is being requested or received.

UM System Availability Performance Counters

The following table provides a list of the system availability performance counters that can be used to monitor Unified Messaging.

System availability performance counters for Unified Messaging

Performance counter	Performance object	Description
Call Answer Queued Messages	MSExchangeAvailability	Call Answer Queued Messages is the number of messages created and not yet submitted for delivery.
Calls Disconnected by UM on Irrecoverable External Error	MSExchangeAvailability	Calls Disconnected by UM on Irrecoverable External Error is the total number of calls disconnected after an irrecoverable external error occurred.
Calls Disconnected by UM on Irrecoverable External Error/sec	MSExchangeAvailability	Calls Disconnected by UM on Irrecoverable External Error per second is the number of calls disconnected after an irrecoverable external error occurred in the last second.
Calls Disconnected on Irrecoverable Internal Error	MSExchangeAvailability	Calls Disconnected on Irrecoverable Internal Error is the number of calls that were disconnected after an internal system error occurred.
Directory Access Failures	MSExchangeAvailability	Directory Access Failures is the number of times that attempts to access Active Directory failed.
Failed to Redirect Call	MSExchangeAvailability	Failed to Redirect Call is the number of times the Microsoft Exchange Unified Messaging service did not redirect calls to a UM worker process.
Hub Transport Access Completed	MSExchangeAvailability	Hub Transport Access Completed is the number of times that the Hub Transport server was accessed successfully.
Hub Transport Access Failures	MSExchangeAvailability	Hub Transport Access Failures is the number of times that attempts to access a Hub Transport server failed. This number is only incremented if all Hub Transport servers were unavailable.
Incomplete Signaling Information	MSExchangeAvailability	Incomplete Signaling Information is the number of calls for which the signaling information was missing or incomplete.
Mailbox Server Access Failures	MSExchangeAvailability	Mailbox Server Access Failures is the number of times the system did not access a Mailbox server.
Maximum Calls Allowed	MSExchangeAvailability	Maximum Calls Allowed is the length of time, in seconds, that the server concurrently processed the maximum number of calls allowed.
Name TTSed	MSExchangeAvailability	Name TTSed is the number of times the system used Text-to-Speech (TTS) to create an audio version of the display name of a subscriber.
Spoken Name Accessed	MSExchangeAvailability	Spoken Name Accessed is the number of times the system retrieved the recorded name of a user.
Total Worker Process Call Count	MSExchangeAvailability	Total Worker Process Call Count is the total number of calls handled by this UM worker process.
Unhandled Exceptions/sec	MSExchangeAvailability	Calls Disconnected on Irrecoverable Internal Error Per Second is the number of calls that were disconnected after an internal system error occurred in the last second. Note The name of this performance counter does not match the name listed in its description.
Worker Process Recycled	MSExchangeAvailability	Worker Process Recycled is the number of times a new UM worker process has been started.

The following table provides a list of the system availability performance counters that were added to Exchange Server 2007 Service Pack 1 (SP1) that can be used to monitor Unified Messaging.

System availability performance counters for Unified Messaging in Exchange 2007 SP1

Performance counter	Performance object	Description
Queued OCS User Event Notifications	MSExchangeAvailability	Queued OCS User Event Notifications is the number of notifications that have been created and not yet submitted for delivery.

For More Information

For more information about the performance objects and counters that are available for Unified Messaging, see Performance Counter Reference for Unified Messaging.
For more information about how to troubleshoot a Unified Messaging server, see Unified Messaging Server Issues.