User's Manual

SSL and Firewalls
Conguring Secure Sockets Layer Authentication 7-13
Note: Although Oracle Connection Manager can be used to avoid
opening up multiple SSL ports through the firewall, consider the
following:
The internal connection, between Oracle Connection Manager
and the database, is not an SSL connection. You should encrypt
such connections, using Oracle Advanced Security native
encryption.
Because such connections do not use SSL, clients cannot use
certificate-based authentication.
See Also: Oracle Net Services Administrator's Guide for information
about Oracle Connection Manager