This article has information on NetScaler Insight Center Round Trip Time (RTT) calculations and troubleshooting tips.

NetScaler Insight Center RTT Calculations

The following points are taken into consideration when calculating the RTT of NetScaler Insight Center:

• RTT calculation is based on the ICA_RTT value.

• ICA RTT is calculated once in 15/30 sec (configurable) and it is an average value.

• WAN and data center latency measure is done more often depending on the TCP traffic.

NetScaler Insight Center RTT Troubleshooting Tips

The following are some of the NetScaler Insight Center RTT issues and their troubleshooting tips:

• There might be cases where clients do see RTT values on the dashboard, but they complain that the RTT values are incorrect.
  In such cases bear in mind that ICA RTT values are calculated for Active ICA connections, if application is idle, than it is expected to get ICA RTT values less than WAN and data center latency. Ideally ICA RTT values must be greater than the sum of WAN latency and data center latency. If the application is not actively sending data, then it does not work as expected. This is because, the TCP RTT estimation works only on active connections. If a connection is not very active or if it is idle, then the data center latency value will be more than ICA RTT or WAN latency. For more information refer to NetScaler Insight Center 10.5 FAQs.

• You are unable to see RTT values on NetScaler Insight Center.

  

  Complete the following steps to troubleshoot this issue:

  1. Verify if client type is supported.

     

     The following table lists the Receiver and operating system versions that support ICA RTT values:

     Operating System	Receiver Version
     Windows 7	3.4 Enterprise Edition 4.0 Standard Edition
     Windows 8	3.4 Enterprise Edition 4.0 Standard Edition
     Mac	11.8, build 238301 and above Note: Mac client does not support ICA RTT reports for CloudBridge version 7.3.0.
     Linux	13 and above

  2. If the client type is supported then verify the following settings on the back end XenApp/XenDesktop server:

     1. Verify server IP details. This can be obtained from the current application sessions on NetScaler Insight Center dashboard.

        

     2. Make sure that the ICA RTT calculation for idle connections is enabled on the XenApp/XenDesktop server. ICA Round Trip policy entries in the registry should be present as well.

        

     3. Make sure that Citrix End User Experience Monitoring (EUEM) is also running on the server and the Startup Type is set to Automatic.

        

     4. Make sure that the value of flowRecordInterval parameter on the NetScaler is set to 60 seconds.

     5. Make sure that the Citrix EUEM Hotfix - XA650R01W2K8R2X64064 for the XenApp 6.5 with R01 server is installed.

Additional Resources

Citrix eDocs - NetScaler Insight Center 10.5 Troubleshooting Tips