This identifies which EMIX frame-size-mix profile a frame-loss result row was measured against, meaningful only when the companion FrameSize field reads 0, in which case FrameSize alone identifies the single fixed size instead. An admin uses this to confirm whether a reported loss percentage reflects performance under realistic blended traffic rather than one artificial frame size, since a device can pass every individual fixed-size test yet still lose frames under a mixed real-world profile. For example, unexpected loss showing up only when cienaCesBenchmarkGenTestSessionFramelossResultsEmixSequenceId = 2 (and not on any fixed frame size) would suggest the device struggles specifically with size-varying traffic, perhaps due to buffer fragmentation.