Transport Component Latencies Test

Transport bottlenecks are one of the common reasons for poor user experience with the Exchange server. Frequent / prolonged breaks in email message flow end-to-end often results in delays/failures in the delivery of business-critical emails, thus impacting revenues, affecting user productivity, and escalating support costs. To ensure the speedy delivery of mails, latencies in mail flow should be proactively spotted and resolved. The Transport Component Latencies test helps with this. This test auto-discovers all transport components engaged in mail flow. Then, at configured intervals, this test reports how long it took each component to process email messages, 90%, 95%, and 99% of the time. In the process, the test reveals latencies in message processing and accurately points to the transport components responsible for the same.

Target of the test : A Microsoft Exchange 2013/2016 server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for each transport component engaged in mail flow

Configurable parameters for the test
  1. Test period - How often should the test be executed
  2. Host - The host for which the test is to be configured.
  3. port – The port at which the host listens.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

90th percentile message latency:

Indicates the maximum time taken by this transport component to process messages 90% of the time.

Secs

If the value of these measures are consistently high for one/more transport components, it could indicate bottlenecks in email flow. The reason for the same has to be ascertained and resolved, so that there is an uninterrupted flow of emails end-to-end. 

High latencies can be triggered by one or more of the following reasons:

  • A networking issue exists.
  • The Transport component of the Microsoft Exchange 2013/2016 is under a heavy load.
  • Some messages have been sent to large distribution groups.
  • A Transport Agent issue exists. For example, the antivirus agent or Rights Management Services agent may be experiencing an issue.

95th percentile message latency:

Indicates the maximum time taken by this transport component to process messages 95% of the time.

Secs

99th percentile message latency:

Indicates the maximum time taken by this transport component to process messages 99% of the time.

Secs