Fix for GitHub issue #20 (untested)

node/Constants.hpp

@@ -302,6 +302,11 @@ error_no_byte_order_defined;
  */
 #define ZT_PEER_LINK_ACTIVITY_TIMEOUT ((ZT_PEER_DIRECT_PING_DELAY * 2) + 1000)
 
+/**
+ * Number of outgoing verb/packetId pairs to keep for sends expecting responses
+ */
+#define ZT_PEER_REQUEST_HISTORY_LENGTH 8
+
 /**
  * IP hops (a.k.a. TTL) to set for firewall opener packets
  *