EXFO FTB-8500 Series for FTB-500 - Manual (Page 253)

Stream Analyzer Tabs
Ethernet and Fibre Channel Application 239
Stream
Stream
Press TEST, Stream Analyzer, and Stream.
Note: Available with Frame Analyzer test only.
Stream No.
Select the stream number from the list.
RX Frame Count
Indicates the number of frame received matching the selected stream ID.
Stream Errors Analysis

Out-Of-Sequence (OOS) is declared when a packet has its sequence
number smaller than the previously received packet.

Frame Loss is declared when missing frames are detected.