The value of tmnxOamTrHopsRttHCSumSquares indicates the sum of squares
of the round trip times of the trace route test for this hop. Its
purpose is to enable the standard deviation calculation.
The value of this object will be reported as 0 when one or more of the
following conditions apply:
1. No round trip time measurement is available.
2. The test stopped before completion.
3. The test type (i.e. tmnxOamTrCtlTestMode) is one of the following:
'ldpTreeTrace',
'mcastTraceRoute',
'p2mpLspTrace'.