As Davey stated, from the database point of view this is an idle event however, this is affecting query performance.

You are experiencing too many round-trips between the client and the server.

This is likely not easy to troubleshoot.

You can start by tracing the most used queries and look for "SQL*Net message from client" wait. As a rule of thumbs take into consideration just queries where this event is greater than the sum of all other wait events.

Once you have identified a offending query... tune it up

Good luck!