JCO accesses SAP over the standard set of SAP ports used to communicate with SAPGUI. In this case, JCO uses ports 3200, 3300, and 3600 depending on how the SAP application server is configured (single server versus message server).
Updated May 18, 2018
JCO accesses SAP over the standard set of SAP ports used to communicate with SAPGUI. In this case, JCO uses ports 3200, 3300, and 3600 depending on how the SAP application server is configured (single server versus message server).