Prior to the release of Applications Manager (AM) version 9.2, AM used a DBMS_PIPE package to connect to the Oracle Applications (OA) databases. Therefore, AM did not support load balancing for multi-node OA databases.
However, an enhancement to AM in 9.2 replaced the DBMS_PIPE package with Oracle Advanced Queuing (AQ) which allows AM to support load balancing for multi-node Oracle Applications databases.
Applications Manager 9.x
Root Cause: In Applications Manager v9.2 the DBMS_PIPE package has been replaced by Oracle Advanced Queuing (AQ) for OAE related code to support Oracle E-Business suite on RAC.