diff --git a/core/api/src/main/java/org/onlab/onos/net/statistic/Load.java b/core/api/src/main/java/org/onlab/onos/net/statistic/Load.java
index 534b10c..b609f2b 100644
--- a/core/api/src/main/java/org/onlab/onos/net/statistic/Load.java
+++ b/core/api/src/main/java/org/onlab/onos/net/statistic/Load.java
@@ -6,15 +6,27 @@
 public interface Load {
 
     /**
-     * Obtain the current observed rate on a link.
+     * Obtain the current observed rate (in bytes/s) on a link.
      * @return long value
      */
     long rate();
 
     /**
-     * Obtain the latest counter viewed on that link.
+     * Obtain the latest bytes counter viewed on that link.
      * @return long value
      */
     long latest();
 
+    /**
+     * Indicates whether this load was built on valid values.
+     * @return boolean
+     */
+    boolean isValid();
+
+    /**
+     * Returns when this value was seen.
+     * @return epoch time
+     */
+    long time();
+
 }