Wait Event : LDAP Operation

Hi All,

DB version is 11.2.0.2  AWR report top 5 wait events i could see

                                                           Avg
                                                          wait   % DB
Event                                 Waits     Time(s)   (ms)   time Wait Class
------------------------------ ------------ ----------- ------ ------ ----------
DB CPU                                               21          62.7
PX Deq: Slave Session Stats             805           6      7   18.2 Other
DBMS_LDAP: LDAP operation               120           4     37   13.5 Other
gc buffer busy acquire                2,211           2      1    7.1 Cluster
gc cr block busy                        796           2      2    5.2 Cluster

The DBMS_LDAP: LDAP operation Avg wait Time(s) is 37ms.  Searching about this event in MOS and google, but not getting the right info. How do i diagnose what is causing this wait event?

Thank you,

Baskar.l