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One possible way to verify the sequence errors is to use Wireshark and export the summary section to a .csv file and import them into a spreadsheet program to analyze the Sequence Numbers (SN) of the streams.

• Open the pcap (see attached pcap) in a version of Wireshark that has a Spirent Signature Field dissector
  • Spirent version available on the CSC: version 1.10.3
  • General version available from Wireshark: version 3.4.4 (and higher)
• Add a couple of columns for the Stream ID (stcsig.streamid) and Sequence Number (stcsig.seqnum).
  • see SOL12911 - Wireshark: How do I add a column in the packet summary section to display a Spirent TestCenter Signature field?
    
• Export the summary section of the pcap
  • Export Packet Dissections -> As CSV...
         
  • Save All packets, packet summary line, and include the column headings (see attached .csv).
         
• Use a spreadsheet program to check for drops (e.g., Excel)
  • Open the .csv, select all the cells, and add a filter
         
  • Under the Stream ID column, select one of the stream IDs
         
  • In an unused column, add a formula to check to see if the Sequence Number (SN) of a packet is one more than the one before it. For example:
         =IF(I5=(I3+1), 0,1)
    That is, if the SN of the 2nd packet is 1 more than the SN of the 1st packet, make it a 0 (no drop occurred), else make it a 1 (a drop occurred).
    The idea is if they are all 0's, there is no drop.
  • Copy that formula down to the rest of the cells.
    • Note we are not guaranteed that rows being skipped are always the same. So, a copy down of the formula won't necessarily be accurate.
    • So, it might be easier, after filtering out the stream ID you are interested in, to copy the records to another worksheet.
    • For example, in the attached .csv,
      • Stream ID 65537 has some rows that are consecutive, whereas
             
      • Stream ID 65536 always skips a row.
  • You can use the summation or subtotal function at the bottom of that column, to see if it is non-zero. If so, then there are drops.
         
• The attached .pcap and .csv has two streams
  • Stream ID 65536 has 9 dropped frames
  • Stream ID 65537 has 0 dropped frames