More "SQL*Net message from client" wait event on a select against nls_session_parameters

Hello Gurus,
Our's is a 5 TB EBS database and we're experiencing some strange situation. One of the self-service page was taking a longer time and I turned on the trace by setting the profile for the user and it generated around 5-6 files. When I tkprof-ed the trace files, I found out that, there's a huge amount of wait time on the event SQL*Net message from client by the following SQL :

select parameter, value
from
 nls_session_parameters

Here're the excerpts from the tkprof output files :

********************************************************************************

select parameter, value
from
 nls_session_parameters


call     count       cpu    elapsed       disk      query    current        rows