Added notion of Flows

node/Constants.hpp

@@ -266,6 +266,12 @@
  */
 #define ZT_LOCAL_CONF_FILE_CHECK_INTERVAL 10000
 
+/**
+ * How long before we consider a flow to be dead and remove it from the balancing
+ * policy's list.
+ */
+#define ZT_MULTIPATH_FLOW_EXPIRATION 60000
+
 /**
  * How frequently to check for changes to the system's network interfaces. When
  * the service decides to use this constant it's because we want to react more