diff --git a/libi2pd/I2NPProtocol.cpp b/libi2pd/I2NPProtocol.cpp
index 5ae89c23..369107b4 100644
--- a/libi2pd/I2NPProtocol.cpp
+++ b/libi2pd/I2NPProtocol.cpp
@@ -36,6 +36,11 @@ namespace i2p
 		return std::make_shared<I2NPMessageBuffer<I2NP_MAX_SHORT_MESSAGE_SIZE> >();
 	}
 
+	std::shared_ptr<I2NPMessage> NewI2NPMediumMessage ()
+	{
+		return std::make_shared<I2NPMessageBuffer<I2NP_MAX_MEDIUM_MESSAGE_SIZE> >();
+	}
+	
 	std::shared_ptr<I2NPMessage> NewI2NPTunnelMessage (bool endpoint)
 	{
 		return i2p::tunnel::tunnels.NewI2NPTunnelMessage (endpoint);
@@ -43,7 +48,10 @@ namespace i2p
 
 	std::shared_ptr<I2NPMessage> NewI2NPMessage (size_t len)
 	{
-		return (len < I2NP_MAX_SHORT_MESSAGE_SIZE - I2NP_HEADER_SIZE - 2) ? NewI2NPShortMessage () : NewI2NPMessage ();
+		len += I2NP_HEADER_SIZE + 2;
+		if (len <= I2NP_MAX_SHORT_MESSAGE_SIZE) return NewI2NPShortMessage ();
+		if (len <= I2NP_MAX_MEDIUM_MESSAGE_SIZE) return NewI2NPMediumMessage ();
+		return NewI2NPMessage ();		
 	}
 
 	void I2NPMessage::FillI2NPMessageHeader (I2NPMessageType msgType, uint32_t replyMsgID, bool checksum)
diff --git a/libi2pd/I2NPProtocol.h b/libi2pd/I2NPProtocol.h
index 80757501..c0685190 100644
--- a/libi2pd/I2NPProtocol.h
+++ b/libi2pd/I2NPProtocol.h
@@ -140,6 +140,7 @@ namespace tunnel
 
 	const size_t I2NP_MAX_MESSAGE_SIZE = 62708;
 	const size_t I2NP_MAX_SHORT_MESSAGE_SIZE = 4096;
+	const size_t I2NP_MAX_MEDIUM_MESSAGE_SIZE = 16384;
 	const unsigned int I2NP_MESSAGE_EXPIRATION_TIMEOUT = 8000; // in milliseconds (as initial RTT)
 	const unsigned int I2NP_MESSAGE_CLOCK_SKEW = 60*1000; // 1 minute in milliseconds
 
@@ -262,6 +263,7 @@ namespace tunnel
 
 	std::shared_ptr<I2NPMessage> NewI2NPMessage ();
 	std::shared_ptr<I2NPMessage> NewI2NPShortMessage ();
+	std::shared_ptr<I2NPMessage> NewI2NPMediumMessage ();
 	std::shared_ptr<I2NPMessage> NewI2NPTunnelMessage (bool endpoint);
 	std::shared_ptr<I2NPMessage> NewI2NPMessage (size_t len);
 
diff --git a/libi2pd/SSU2Session.cpp b/libi2pd/SSU2Session.cpp
index 9a2fea9a..4d3a9866 100644
--- a/libi2pd/SSU2Session.cpp
+++ b/libi2pd/SSU2Session.cpp
@@ -23,7 +23,7 @@ namespace transport
 		if (msg->len + fragmentSize > msg->maxLen)
 		{
 			LogPrint (eLogInfo, "SSU2: I2NP message size ", msg->maxLen, " is not enough");
-			auto newMsg = NewI2NPMessage ();
+			auto newMsg = NewI2NPMessage (msg->len + fragmentSize);
 			*newMsg = *msg;
 			msg = newMsg;
 		}
diff --git a/libi2pd/TunnelEndpoint.cpp b/libi2pd/TunnelEndpoint.cpp
index 9c294374..7d3b3cbe 100644
--- a/libi2pd/TunnelEndpoint.cpp
+++ b/libi2pd/TunnelEndpoint.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2020, The PurpleI2P Project
+* Copyright (c) 2013-2023, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -208,7 +208,7 @@ namespace tunnel
 			if (msg.data->len + size > msg.data->maxLen)
 			{
 			//	LogPrint (eLogWarning, "TunnelMessage: I2NP message size ", msg.data->maxLen, " is not enough");
-				auto newMsg = NewI2NPMessage ();
+				auto newMsg = NewI2NPMessage (msg.data->len + size);
 				*newMsg = *(msg.data);
 				msg.data = newMsg;
 			}
@@ -297,11 +297,11 @@ namespace tunnel
 			if (msg.data->len + size > msg.data->maxLen)
 			{
 				LogPrint (eLogWarning, "TunnelMessage: Tunnel endpoint I2NP message size ", msg.data->maxLen, " is not enough");
-				auto newMsg = NewI2NPMessage ();
+				auto newMsg = NewI2NPMessage (msg.data->len + size);
 				*newMsg = *(msg.data);
 				msg.data = newMsg;
 			}
-			if (msg.data->Concat (it->second->data.data (), size) < size) // concatenate out-of-sync fragment
+			if (msg.data->Concat (it->second->data.data (), size) < size) // concatenate out-of-sync fragment	
 				LogPrint (eLogError, "TunnelMessage: Tunnel endpoint I2NP buffer overflow ", msg.data->maxLen);
 			if (it->second->isLastFragment)
 				// message complete