Applies to: Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2007-08-29

This topic provides information about performance counters and suggestions about how to improve network performance. The network and how it is deployed is essential to the proper performance of an Exchange server. It is uncommon for networks to be network-bound because 100 megabits per second (Mbps) networks generally offer enough bandwidth for most organizations. However, with increasing message sizes and users per server, it is important to make sure that the network does not become a bottleneck.

Use the performance monitor counters listed in the following table to determine whether there is any network performance degradation.

Performance counters for networks

Counter Expected values

Network Interface\Bytes Total/sec

Indicates the rate at which the network adapter is processing data bytes.

This counter includes all application and file data, in addition to protocol information such as packet headers.
  • For a 100-Mbps network adapter, the counter should be below 6–7  MB per second (sec).

  • For a 1000-Mbps network adapter, the counter should be below 60–70 MB/sec.

Network Interface\Packets Outbound Errors

Indicates the number of outbound packets that could not be transmitted because of errors.
  • The counter should be zero (0) at all times.

Improving Network Performance

When there is significant traffic, and therefore overhead due to packet collision, you can improve network performance by separating inter-server and global catalog traffic from client traffic. You can do this by having servers and global catalogs with dual network adapters, and by building a separate network for the communication required by servers and global catalogs.