change path if too many unacked packets

libi2pd_client/UDPTunnel.h

@@ -30,7 +30,9 @@ namespace client
 	/** 2 minute timeout for udp sessions */
 	const uint64_t I2P_UDP_SESSION_TIMEOUT = 1000 * 60 * 2;
 	const uint64_t I2P_UDP_REPLIABLE_DATAGRAM_INTERVAL = 100; // in milliseconds
-
+	const uint64_t I2P_UDP_MAX_UNACKED_DATAGRAM_TIME = 8000; // in milliseconds
+	const size_t I2P_UDP_MAX_NUM_UNACKED_DATAGRAMS = 500;
+	
 	/** max size for i2p udp */
 	const size_t I2P_UDP_MAX_MTU = 64*1024;