code: protected void encodeMandatoryParameters(Map<Integer, ISUPParameter> parameters, ByteArrayOutputStream bos)
              throws ParameterException {
          // 1.5 Mandatory fixed part
          // Those parameters that are mandatory and of fixed length for a
          // particular message type will be
          // contained in the mandatory fixed part. The position, length and order
          // of the parameters is uniquely
          // defined by the message type; thus, the names of the parameters and
          // the length indicators are not
          // included in the message.
          if (this.cic == null) {
              // this will be changed to different exception
              throw new ParameterException("CIC is not set!");
          }
          ((AbstractISUPParameter) this.cic).encode(bos);
          for (ISUPParameter p : parameters.values()) {
              ((AbstractISUPParameter) p).encode(bos);
          }
      }
docs: NOTE: those methods are more or less generic.