diff --git a/ClientContext.cpp b/ClientContext.cpp
index 2c917025..68115402 100644
--- a/ClientContext.cpp
+++ b/ClientContext.cpp
@@ -17,7 +17,8 @@ namespace client
 
 	ClientContext::ClientContext (): m_SharedLocalDestination (nullptr),
 		m_HttpProxy (nullptr), m_SocksProxy (nullptr), m_SamBridge (nullptr), 
-		m_BOBCommandChannel (nullptr), m_I2CPServer (nullptr)
+    m_BOBCommandChannel (nullptr), m_I2CPServer (nullptr),
+    m_CleanupUDPTimer(m_Service, boost::posix_time::seconds(1))
 	{
 	}
 	
@@ -39,6 +40,13 @@ namespace client
 			m_SharedLocalDestination->Start ();
 		}
 
+    if ( m_ServiceThread == nullptr ) {
+      m_ServiceThread = new std::thread([&] () {
+          m_Service.run();
+      });
+      ScheduleCleanupUDP();
+    }
+    
 		m_AddressBook.Start ();	
 		
 		std::shared_ptr<ClientDestination> localDestination;	
@@ -195,11 +203,26 @@ namespace client
 		}
 
 		LogPrint(eLogInfo, "Clients: stopping AddressBook");
-		m_AddressBook.Stop ();		
+		m_AddressBook.Stop ();
+
+    {
+      std::lock_guard<std::mutex> lock(m_ForwardsMutex);
+      m_ServerForwards.clear();
+      m_ClientForwards.clear();
+    }
+    
+    
 		for (auto& it: m_Destinations)
 			it.second->Stop ();
 		m_Destinations.clear ();
-		m_SharedLocalDestination = nullptr; 
+		m_SharedLocalDestination = nullptr;
+    // stop io service thread
+    if(m_ServiceThread) {
+      m_Service.stop();
+      m_ServiceThread->join();
+      delete m_ServiceThread;
+      m_ServiceThread = nullptr;
+    }
 	}	
 
 	void ClientContext::ReloadConfig ()
@@ -349,7 +372,7 @@ namespace client
 			try
 			{
 				std::string type = section.second.get<std::string> (I2P_TUNNELS_SECTION_TYPE);
-				if (type == I2P_TUNNELS_SECTION_TYPE_CLIENT)
+				if (type == I2P_TUNNELS_SECTION_TYPE_CLIENT || type == I2P_TUNNELS_SECTION_TYPE_UDPCLIENT)
 				{
 					// mandatory params
 					std::string dest = section.second.get<std::string> (I2P_CLIENT_TUNNEL_DESTINATION);
@@ -374,17 +397,34 @@ namespace client
 								localDestination = CreateNewLocalDestination (k, false, &options);
 						}
 					}
-					auto clientTunnel = new I2PClientTunnel (name, dest, address, port, localDestination, destinationPort);
-					if (m_ClientTunnels.insert (std::make_pair (clientTunnel->GetAcceptor ().local_endpoint (), 
-						std::unique_ptr<I2PClientTunnel>(clientTunnel))).second)
-					{
-						clientTunnel->Start ();
-						numClientTunnels++;
-					}
-					else
-						LogPrint (eLogError, "Clients: I2P client tunnel for endpoint ", clientTunnel->GetAcceptor ().local_endpoint (), " already exists");
+          if (type == I2P_TUNNELS_SECTION_TYPE_UDPCLIENT) {
+            // udp client
+            // TODO: ip6 and hostnames
+            boost::asio::ip::udp::endpoint end(boost::asio::ip::address::from_string(address), port);
+            if(destinationPort == 0) {
+              destinationPort = port;
+            }
+            auto clientTunnel = new I2PUDPClientTunnel(name, dest, end, localDestination, destinationPort, m_Service);
+            if(m_ClientForwards.insert(std::make_pair(end, std::unique_ptr<I2PUDPClientTunnel>(clientTunnel))).second) {
+              clientTunnel->Start();
+            } else {
+              LogPrint(eLogError, "Clients: I2P Client forward for endpoint ", end, " already exists");
+              delete clientTunnel;
+            }
+          } else {
+            // tcp client
+            auto clientTunnel = new I2PClientTunnel (name, dest, address, port, localDestination, destinationPort);
+            if (m_ClientTunnels.insert (std::make_pair (clientTunnel->GetAcceptor ().local_endpoint (), 
+              std::unique_ptr<I2PClientTunnel>(clientTunnel))).second)
+            {
+              clientTunnel->Start ();
+              numClientTunnels++;
+            }
+            else
+              LogPrint (eLogError, "Clients: I2P client tunnel for endpoint ", clientTunnel->GetAcceptor ().local_endpoint (), " already exists");
+          }
 				}
-				else if (type == I2P_TUNNELS_SECTION_TYPE_SERVER || type == I2P_TUNNELS_SECTION_TYPE_HTTP || type == I2P_TUNNELS_SECTION_TYPE_IRC)
+				else if (type == I2P_TUNNELS_SECTION_TYPE_SERVER || type == I2P_TUNNELS_SECTION_TYPE_HTTP || type == I2P_TUNNELS_SECTION_TYPE_IRC || type == I2P_TUNNELS_SECTION_TYPE_UDPSERVER)
 				{	
 					// mandatory params
 					std::string host = section.second.get<std::string> (I2P_SERVER_TUNNEL_HOST);
@@ -411,6 +451,25 @@ namespace client
 					if (!localDestination)		
 						localDestination = CreateNewLocalDestination (k, true, &options);
 
+          if (type == I2P_TUNNELS_SECTION_TYPE_UDPSERVER) {
+            // udp server tunnel
+            // TODO: ipv6 and hostnames
+            boost::asio::ip::udp::endpoint endpoint(boost::asio::ip::address::from_string(host), port);
+            I2PUDPServerTunnel * serverTunnel = new I2PUDPServerTunnel(name, localDestination, endpoint, port, m_Service);
+            std::lock_guard<std::mutex> lock(m_ForwardsMutex);
+            if(m_ServerForwards.insert(
+              std::make_pair(
+                std::make_pair(
+                  localDestination->GetIdentHash(), port),
+                std::unique_ptr<I2PUDPServerTunnel>(serverTunnel))).second) {
+              LogPrint(eLogInfo, "Cleints: I2P Server Forward created for UDP Endpoint ", host, ":", port);
+            } else {
+              LogPrint(eLogError, "Clients: I2P Server Forward for destination/port ", m_AddressBook.ToAddress(localDestination->GetIdentHash()), "/", port, "already exists");
+              delete serverTunnel;
+            }
+            continue;
+          }
+          
 					I2PServerTunnel * serverTunnel;
 					if (type == I2P_TUNNELS_SECTION_TYPE_HTTP)
                     	serverTunnel = new I2PServerTunnelHTTP (name, host, port, localDestination, hostOverride, inPort, gzip);
@@ -460,6 +519,22 @@ namespace client
 		}	
 		LogPrint (eLogInfo, "Clients: ", numClientTunnels, " I2P client tunnels created");
 		LogPrint (eLogInfo, "Clients: ", numServerTunnels, " I2P server tunnels created");
-	}	
+	}
+  void ClientContext::ScheduleCleanupUDP()
+  {
+    // schedule cleanup in 1 second
+    m_CleanupUDPTimer.expires_at(m_CleanupUDPTimer.expires_at() + boost::posix_time::seconds(1));
+    m_CleanupUDPTimer.async_wait(std::bind(&ClientContext::CleanupUDP, this, std::placeholders::_1));
+  }
+
+  void ClientContext::CleanupUDP(const boost::system::error_code & ecode)
+  {
+    if(!ecode) {
+      std::lock_guard<std::mutex> lock(m_ForwardsMutex);
+      for ( auto & s : m_ServerForwards ) {
+        s.second->ExpireStale();
+      }
+    }
+  }
 }		
 }	
diff --git a/ClientContext.h b/ClientContext.h
index 55176b91..5a054f29 100644
--- a/ClientContext.h
+++ b/ClientContext.h
@@ -24,6 +24,8 @@ namespace client
 	const char I2P_TUNNELS_SECTION_TYPE_SERVER[] = "server";
 	const char I2P_TUNNELS_SECTION_TYPE_HTTP[] = "http";
 	const char I2P_TUNNELS_SECTION_TYPE_IRC[] = "irc";
+  const char I2P_TUNNELS_SECTION_TYPE_UDPCLIENT[] = "udpclient";
+  const char I2P_TUNNELS_SECTION_TYPE_UDPSERVER[] = "udpserver";
 	const char I2P_CLIENT_TUNNEL_PORT[] = "port";
 	const char I2P_CLIENT_TUNNEL_ADDRESS[] = "address";
 	const char I2P_CLIENT_TUNNEL_DESTINATION[] = "destination";
@@ -72,7 +74,10 @@ namespace client
 			template<typename Section>
 			void ReadI2CPOptions (const Section& section, std::map<std::string, std::string>& options) const;	
 
-		private:
+      void CleanupUDP(const boost::system::error_code & ecode);
+      void ScheduleCleanupUDP();
+      
+    private:
 
 			std::mutex m_DestinationsMutex;
 			std::map<i2p::data::IdentHash, std::shared_ptr<ClientDestination> > m_Destinations;
@@ -84,10 +89,21 @@ namespace client
 			i2p::proxy::SOCKSProxy * m_SocksProxy;
 			std::map<boost::asio::ip::tcp::endpoint, std::unique_ptr<I2PClientTunnel> > m_ClientTunnels; // local endpoint->tunnel
 			std::map<std::pair<i2p::data::IdentHash, int>, std::unique_ptr<I2PServerTunnel> > m_ServerTunnels; // <destination,port>->tunnel
-			SAMBridge * m_SamBridge;
+
+      std::mutex m_ForwardsMutex;
+      
+      std::map<boost::asio::ip::udp::endpoint, std::unique_ptr<I2PUDPClientTunnel> > m_ClientForwards; // local endpoint -> udp tunnel
+      std::map<std::pair<i2p::data::IdentHash, int>, std::unique_ptr<I2PUDPServerTunnel> > m_ServerForwards; // <destination,port> -> udp tunnel
+      
+      SAMBridge * m_SamBridge;
 			BOBCommandChannel * m_BOBCommandChannel;
 			I2CPServer * m_I2CPServer;
 
+      boost::asio::io_service m_Service;
+      std::thread * m_ServiceThread;
+
+      boost::asio::deadline_timer m_CleanupUDPTimer;
+      
 		public:
 			// for HTTP
 			const decltype(m_Destinations)& GetDestinations () const { return m_Destinations; };
diff --git a/I2PTunnel.cpp b/I2PTunnel.cpp
index 87764a84..e639c12a 100644
--- a/I2PTunnel.cpp
+++ b/I2PTunnel.cpp
@@ -511,5 +511,153 @@ namespace client
         conn->Connect ();
     }
 
+  void I2PUDPServerTunnel::HandleRecvFromI2P(const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len)
+  {
+    std::lock_guard<std::mutex> lock(m_SessionsMutex);
+    auto & session = ObtainUDPSession(from, toPort, fromPort);
+    
+    session.IPSocket.send_to(boost::asio::buffer(buf, len), m_Endpoint);
+    session.LastActivity = i2p::util::GetMillisecondsSinceEpoch();
+    
+  }
+
+  void I2PUDPServerTunnel::ExpireStale(const uint64_t delta) {
+    std::lock_guard<std::mutex> lock(m_SessionsMutex);
+    uint64_t now = i2p::util::GetMillisecondsSinceEpoch();
+    std::remove_if(m_Sessions.begin(), m_Sessions.end(), [now, delta](const UDPSession & u) -> bool {
+      return now - u.LastActivity >= delta;
+    });
+  }
+  
+  UDPSession & I2PUDPServerTunnel::ObtainUDPSession(const i2p::data::IdentityEx& from, uint16_t localPort, uint16_t remotePort)
+  {
+    auto ih = from.GetIdentHash();
+    for ( UDPSession & s : m_Sessions ) {
+      if ( s.Identity == ih) {
+        /** found existing */
+        return s;
+      }
+    }
+    /** create new */
+    m_Sessions.push_back(UDPSession(m_Service, m_Destination, m_Endpoint, ih, localPort, remotePort));
+    return m_Sessions.back();
+  }
+
+  UDPSession::UDPSession(boost::asio::io_service & ios, std::shared_ptr<i2p::client::ClientDestination> localDestination, boost::asio::ip::udp::endpoint endpoint, const i2p::data::IdentHash from, uint16_t ourPort, uint16_t theirPort) :
+    Destination(localDestination),
+    IPSocket(ios, boost::asio::ip::udp::endpoint(boost::asio::ip::udp::v4(), 0)),
+    Identity(from),
+    ExpectedEndpoint(endpoint),
+    LocalPort(ourPort),
+    RemotePort(theirPort)
+  {
+    Receive();
+  }
+
+
+  void UDPSession::Receive() {
+    IPSocket.async_receive_from(boost::asio::buffer(m_Buffer, I2P_UDP_MAX_MTU), FromEndpoint, std::bind(&UDPSession::HandleReceived, this, std::placeholders::_1, std::placeholders::_2));
+  }
+  
+  void UDPSession::HandleReceived(const boost::system::error_code & ecode, std::size_t len)
+  {
+    if(!ecode) {
+      i2p::datagram::DatagramDestination * dgram = Destination->GetDatagramDestination();
+      if(dgram) {
+        LastActivity = i2p::util::GetMillisecondsSinceEpoch();
+        dgram->SendDatagramTo(m_Buffer, len, Identity, LocalPort, RemotePort);
+      }
+      Receive();
+    }
+  }
+  
+  I2PUDPServerTunnel::I2PUDPServerTunnel(const std::string & name, std::shared_ptr<i2p::client::ClientDestination> localDestination, boost::asio::ip::udp::endpoint forwardTo, uint16_t port, boost::asio::io_service & service) :
+    LocalPort(port),
+    m_Endpoint(forwardTo),
+    m_Service(service),
+    m_Destination(localDestination)
+  {
+    i2p::datagram::DatagramDestination * dgram = m_Destination->CreateDatagramDestination();
+    if(dgram)
+      dgram->SetReceiver(std::bind(&I2PUDPServerTunnel::HandleRecvFromI2P, this, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3, std::placeholders::_4, std::placeholders::_5), LocalPort);
+  }
+
+  I2PUDPServerTunnel::~I2PUDPServerTunnel()
+  {
+    i2p::datagram::DatagramDestination * dgram = m_Destination->GetDatagramDestination();
+    if (dgram) {
+      dgram->ResetReceiver(LocalPort);
+    }
+  }
+
+  I2PUDPClientTunnel::I2PUDPClientTunnel(const std::string & name, const std::string &remoteDest, boost::asio::ip::udp::endpoint localEndpoint, std::shared_ptr<i2p::client::ClientDestination> localDestination, uint16_t remotePort, boost::asio::io_service & service) :
+    m_Session(nullptr),
+    m_RemoteDest(remoteDest),
+    m_RemoteIdent(nullptr),
+    m_LocalDest(localDestination),
+    m_LocalEndpoint(localEndpoint),
+    m_ResolveThread(nullptr),
+    m_Service(service),
+    LocalPort(localEndpoint.port()),
+    RemotePort(remotePort),
+    m_cancel_resolve(false)
+  {
+    
+  }
+
+  
+  
+  void I2PUDPClientTunnel::Start() {
+    if (m_ResolveThread == nullptr)
+      m_ResolveThread = new std::thread(std::bind(&I2PUDPClientTunnel::TryResolving, this));
+  }
+
+  void I2PUDPClientTunnel::TryResolving() {
+    LogPrint(eLogInfo, "UDP Tunnel: Trying to resolve ", m_RemoteDest);
+    m_RemoteIdent = new i2p::data::IdentHash;
+    m_RemoteIdent->Fill(0);
+    while(!context.GetAddressBook().GetIdentHash(m_RemoteDest, *m_RemoteIdent) && !m_cancel_resolve) {
+      LogPrint(eLogWarning, "UDP Tunnel: failed to lookup ", m_RemoteDest);
+      std::this_thread::sleep_for(std::chrono::seconds(1));
+    }
+    if(m_cancel_resolve) {
+      LogPrint(eLogError, "UDP Tunnel: lookup of ", m_RemoteDest, " was cancelled");
+      return;
+    }
+    // delete existing session
+    if(m_Session) delete m_Session;
+    m_Session = new UDPSession(m_Service, m_LocalDest, m_LocalEndpoint, *m_RemoteIdent, LocalPort, RemotePort);
+    auto dgram = m_LocalDest->CreateDatagramDestination();
+    dgram->SetReceiver(std::bind(&I2PUDPClientTunnel::HandleRecvFromI2P, this,
+                                 std::placeholders::_1, std::placeholders::_2,
+                                 std::placeholders::_3, std::placeholders::_4,
+                                 std::placeholders::_5), LocalPort);
+  }
+
+  void I2PUDPClientTunnel::HandleRecvFromI2P(const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len)
+  {
+    if(m_RemoteIdent && from.GetIdentHash() == *m_RemoteIdent) {
+      // address match
+      if(m_Session) {
+        // tell session
+        m_Session->IPSocket.send_to(boost::asio::buffer(buf, len), m_LocalEndpoint);
+      }
+    }
+  }
+  
+  I2PUDPClientTunnel::~I2PUDPClientTunnel() {
+    auto dgram = m_LocalDest->GetDatagramDestination();
+    if (dgram) {
+      dgram->ResetReceiver(LocalPort);
+    }
+    if (m_Session) delete m_Session;
+    m_cancel_resolve = true;
+    if(m_ResolveThread) {
+      m_ResolveThread->join();
+      delete m_ResolveThread;
+      m_ResolveThread = nullptr;
+    }
+    if (m_RemoteIdent) delete m_RemoteIdent;
+  }
 }		
 }	
diff --git a/I2PTunnel.h b/I2PTunnel.h
index f0332722..232ed2ef 100644
--- a/I2PTunnel.h
+++ b/I2PTunnel.h
@@ -9,6 +9,7 @@
 #include <boost/asio.hpp>
 #include "Identity.h"
 #include "Destination.h"
+#include "Datagram.h"
 #include "Streaming.h"
 #include "I2PService.h"
 
@@ -128,8 +129,79 @@ namespace client
 			std::string m_Name, m_Destination;
 			const i2p::data::IdentHash * m_DestinationIdentHash;
 			int m_DestinationPort;	
-	};	
+	};
+
 
+  /** 2 minute timeout for udp sessions */
+  const uint64_t I2P_UDP_SESSION_TIMEOUT = 1000 * 60 * 2;
+
+  /** max size for i2p udp */
+  const size_t I2P_UDP_MAX_MTU = i2p::datagram::MAX_DATAGRAM_SIZE;
+  
+  struct UDPSession
+  {
+    std::shared_ptr<i2p::client::ClientDestination> Destination;
+    boost::asio::ip::udp::socket IPSocket;
+    i2p::data::IdentHash Identity;
+    boost::asio::ip::udp::endpoint ExpectedEndpoint;
+    boost::asio::ip::udp::endpoint FromEndpoint;
+    uint64_t LastActivity;
+
+    uint16_t LocalPort;
+    uint16_t RemotePort;
+
+    uint8_t m_Buffer[I2P_UDP_MAX_MTU];
+    
+    UDPSession(boost::asio::io_service & ios, std::shared_ptr<i2p::client::ClientDestination> localDestination, boost::asio::ip::udp::endpoint remote, const i2p::data::IdentHash ident, uint16_t ourPort, uint16_t theirPort);
+
+    void HandleReceived(const boost::system::error_code & ecode, std::size_t len);
+    void Receive();
+    
+  };
+
+  /** server side udp tunnel, many i2p inbound to 1 ip outbound */
+  class I2PUDPServerTunnel
+  {
+  public:
+    I2PUDPServerTunnel(const std::string & name, std::shared_ptr<i2p::client::ClientDestination> localDestination, boost::asio::ip::udp::endpoint forwardTo, uint16_t port, boost::asio::io_service & service);
+    ~I2PUDPServerTunnel();
+    /** expire stale udp conversations */
+    void ExpireStale(const uint64_t delta=I2P_UDP_SESSION_TIMEOUT);
+
+  private:
+    void HandleRecvFromI2P(const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);
+    UDPSession & ObtainUDPSession(const i2p::data::IdentityEx& from, uint16_t localPort, uint16_t remotePort);
+  private:
+    const uint16_t LocalPort;
+    boost::asio::ip::udp::endpoint m_Endpoint;
+    std::mutex m_SessionsMutex;
+    std::vector<UDPSession> m_Sessions;
+    boost::asio::io_service & m_Service;
+    std::shared_ptr<i2p::client::ClientDestination> m_Destination;
+    uint8_t m_Buffer[I2P_UDP_MAX_MTU];
+  };
+
+  class I2PUDPClientTunnel
+  {
+  public:
+    I2PUDPClientTunnel(const std::string & name, const std::string &remoteDest, boost::asio::ip::udp::endpoint localEndpoint, std::shared_ptr<i2p::client::ClientDestination> localDestination, uint16_t remotePort, boost::asio::io_service & service);
+    ~I2PUDPClientTunnel();
+    void Start();
+  private:
+    void HandleRecvFromI2P(const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);
+    void TryResolving();
+    UDPSession * m_Session;
+    const std::string m_RemoteDest;
+    std::shared_ptr<i2p::client::ClientDestination> m_LocalDest;
+    i2p::data::IdentHash * m_RemoteIdent;
+    const boost::asio::ip::udp::endpoint m_LocalEndpoint;
+    std::thread * m_ResolveThread;
+    boost::asio::io_service & m_Service;
+    uint16_t LocalPort;
+    uint16_t RemotePort;
+    bool m_cancel_resolve;
+  };
+  
 	class I2PServerTunnel: public I2PService
 	{
 		public:
@@ -150,7 +222,7 @@ namespace client
 			const char* GetName() { return m_Name.c_str (); }	
 
       void SetMaxConnsPerMinute(const uint32_t conns) { m_PortDestination->SetMaxConnsPerMinute(conns); }
-      
+
   private:
 
 			void HandleResolve (const boost::system::error_code& ecode, boost::asio::ip::tcp::resolver::iterator it, 
@@ -167,7 +239,7 @@ namespace client
 			boost::asio::ip::tcp::endpoint m_Endpoint;	
 			std::shared_ptr<i2p::stream::StreamingDestination> m_PortDestination;
 			std::set<i2p::data::IdentHash> m_AccessList;
-			bool m_IsAccessList;			
+			bool m_IsAccessList;
 	};
 
 	class I2PServerTunnelHTTP: public I2PServerTunnel
diff --git a/Identity.h b/Identity.h
index d9fb7761..8f3e9e9d 100644
--- a/Identity.h
+++ b/Identity.h
@@ -92,6 +92,8 @@ namespace data
 			CryptoKeyType GetCryptoKeyType () const;
 			void DropVerifier () const; // to save memory			
 
+      bool operator == (const IdentityEx & other) const { return GetIdentHash() == other.GetIdentHash(); }
+      
 		private:
 
 			void CreateVerifier () const;
diff --git a/Tag.h b/Tag.h
index b6f94de7..6e5638a4 100644
--- a/Tag.h
+++ b/Tag.h
@@ -50,6 +50,11 @@ namespace data {
 				return true;
 			}
 
+      /** fill with a value */
+      void Fill(uint8_t c) {
+        memset(m_Buf, c, sz);
+      }
+      
 			std::string ToBase64 () const
 			{
 				char str[sz*2];