+ /**
+ * If the message is from the call originating device, or the
+ * other side.
+ *
+ * - 0 = device that originated the call
+ * - 1 = device that answers to orignator requests
+ *
+ * @var integer
+ */
+ public $callRefType;
+
+ /**
+ * Service AccessPoint Identifier
+ *
+ * @var integer
+ */
+ public $sapi;
+
+ /**
+ * Call/Response bit
+ *
+ * Is 1 when the message contains a command to the TE or
+ * the answer to a command from the TE.
+ *
+ * 0 when it it is a request from the TE to the network,
+ * or the answer to a TE request.
+ *
+ * @var integer
+ */
+ public $callResponse;
+