Resolution:
There is no 'setnopt' command in the SmartSockets API for assigning connection-specific option values, but that is because the concept of options applying only to a specific connection object is native to the Java implementation. The method for setting options is in the TipcConnClient class, and the method is setOption.  In Java each connection is it's own class instaniation, and therefore when options are set they are set in the contaxt of that instance/object.  

Consider the following lines of code:

// the sender connection
TipcSrv sender = TipcSvc.createSrv();
sender.setOption("ss.unique_subject", "sender");

// the receiver connection
TipcSrv receiver = TipcSvc.createSrv();
receiver.setOption("ss.unique_subject", "receiver");

Notice that when the setOption method is called, it is done in the context of a specific "named" connection object (either sender.setOption, or receiver.setOption) and thus it bahaves exactly as setnopt would in the C environment.