Rough draft of fq-codel implementation

node/Constants.hpp

@@ -410,6 +410,41 @@
  */
 #define ZT_PATH_IMBALANCE_THRESHOLD 0.20
 
+/**
+ * Max allowable time spent in any queue
+ */
+#define ZT_QOS_TARGET 5 // ms
+
+/**
+ * Time period where the time spent in the queue by a packet should fall below
+ * target at least once
+ */
+#define ZT_QOS_INTERVAL 100 // ms
+
+/**
+ * The number of bytes that each queue is allowed to send during each DRR cycle.
+ * This approximates a single-byte-based fairness queuing scheme
+ */
+#define ZT_QOS_QUANTUM ZT_DEFAULT_MTU
+
+/**
+ * The maximum total number of packets that can be queued among all
+ * active/inactive, old/new queues
+ */
+#define ZT_QOS_MAX_ENQUEUED_PACKETS 1024
+
+/**
+ * Number of QoS queues (buckets)
+ */
+#define ZT_QOS_NUM_BUCKETS 9
+
+/**
+ * All unspecified traffic is put in this bucket. Anything in a bucket with a smaller
+ * value is de-prioritized. Anything in a bucket with a higher value is prioritized over
+ * other traffic.
+ */
+#define ZT_QOS_DEFAULT_BUCKET 0
+
 /**
  * How frequently to send heartbeats over in-use paths
  */