This identifies which EMIX frame-size-mix profile the PDV results in this row were measured against, meaningful only when the companion FrameSize field reads 0, in which case FrameSize alone identifies a single fixed test frame size. An admin uses this to know whether a jitter figure reflects realistic mixed traffic (which often produces worse jitter due to head-of-line blocking from bigger frames delaying smaller ones) or an artificial single-size stream. For example, PDV that looks fine under every single fixed frame size but spikes when cienaCesBenchmarkGenTestSessionPdvResultsEmixSequenceId identifies an active EMIX profile would reveal a mixed-traffic-specific jitter issue that single-size testing alone would have missed.