When user accessed Virtual Desktop via NetScaler, admin may find the "ICA latency" in Director frequently displays unreasonable high value(not 64000ms), while "ICA RTT" value is in normal range. It's telling ICA RTT >ICA latency.
In fact, users have no high latency or bad interaction experience while using Virtual Desktop. 

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From NetScaler release 13.0 build 83.17+,13.1 build 11.2+, you can specify a time interval, in seconds, for which the L7 client latency value is to be calculated in NetScaler.

Apply the following command in NetScaler as a workaround:

• For NetScaler release before 13.0 build 83.17,13.1 build 11.2, please schedule to upgrade your NetScaler to the fixed version with priority. While you may disable NetScaler L7 client latency calculation as a temporary workaround by applying below shell command:

#nsapimgr -ys enable_ica_l7_latency=0

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Problem Cause

It's a false positive alarm regarding user's poor experience. The incorrect ICA Latency value is miscalculated while involving NetScaler's L7 client latency value.