SQL*Net vector message from client

Just a few days ago I talked about a lesson learned during our DR exercise, and another thing I picked up was actually not from our DR instance!  With the way we needed to carry out our exercise we stopped our GoldenGate replication and the archive log shipping as well, so when we kept an eye on our PROD system via my often referenced wait event script I noticed when the wait event "SQL*Net vector message from client" showed up.  Not only did it show up, it was right at the top.  I have seen GoldenGate replications stopped before without this event showing up, and there were no negative effects seen in our system, so my assumption is that it is related to the archive log shipping that was stopped.  Next time I see the wait event I will have to do more research on the PROD system to see exactly what processes are getting caught in this and what the origin is so I can solve this mystery!