diff --git a/I2NPProtocol.cpp b/I2NPProtocol.cpp
index a9c1f1f3..3ad54ff5 100644
--- a/I2NPProtocol.cpp
+++ b/I2NPProtocol.cpp
@@ -464,26 +464,26 @@ namespace i2p
 	I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, const uint8_t * buf, size_t len)
 	{
 		I2NPMessage * msg = NewI2NPMessage (len);
-		TunnelGatewayHeader * header = (TunnelGatewayHeader *)msg->GetPayload ();
-		header->tunnelID = htobe32 (tunnelID);
-		header->length = htobe16 (len);
-		memcpy (msg->GetPayload () + sizeof (TunnelGatewayHeader), buf, len);
-		msg->len += sizeof (TunnelGatewayHeader) + len;
+		uint8_t * payload = msg->GetPayload ();
+		htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID);
+		htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len);
+		memcpy (payload + TUNNEL_GATEWAY_HEADER_SIZE, buf, len);
+		msg->len += TUNNEL_GATEWAY_HEADER_SIZE + len;
 		FillI2NPMessageHeader (msg, eI2NPTunnelGateway);
 		return msg;
 	}	
 
 	I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessage * msg)
 	{
-		if (msg->offset >= sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader))
+		if (msg->offset >= I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE)
 		{
 			// message is capable to be used without copying
-			TunnelGatewayHeader * header = (TunnelGatewayHeader *)(msg->GetBuffer () - sizeof (TunnelGatewayHeader));
-			header->tunnelID = htobe32 (tunnelID);
+			uint8_t * payload = msg->GetBuffer () - TUNNEL_GATEWAY_HEADER_SIZE;
+			htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID);
 			int len = msg->GetLength ();
-			header->length = htobe16 (len);
-			msg->offset -= (sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader));
-			msg->len = msg->offset + sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader) +len;
+			htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len);
+			msg->offset -= (I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE);
+			msg->len = msg->offset + I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE +len;
 			FillI2NPMessageHeader (msg, eI2NPTunnelGateway);
 			return msg;
 		}
@@ -499,7 +499,7 @@ namespace i2p
 		const uint8_t * buf, size_t len, uint32_t replyMsgID)
 	{
 		I2NPMessage * msg = NewI2NPMessage (len);
-		size_t gatewayMsgOffset = sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader);
+		size_t gatewayMsgOffset = I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE;
 		msg->offset += gatewayMsgOffset;
 		msg->len += gatewayMsgOffset;
 		memcpy (msg->GetPayload (), buf, len);
@@ -507,24 +507,25 @@ namespace i2p
 		FillI2NPMessageHeader (msg, msgType, replyMsgID); // create content message
 		len = msg->GetLength ();
 		msg->offset -= gatewayMsgOffset;
-		TunnelGatewayHeader * header = (TunnelGatewayHeader *)msg->GetPayload ();
-		header->tunnelID = htobe32 (tunnelID);
-		header->length = htobe16 (len);
+		uint8_t * payload = msg->GetPayload ();
+		htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID);
+		htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len);
 		FillI2NPMessageHeader (msg, eI2NPTunnelGateway); // gateway message
 		return msg;
 	}	
 	
 	void HandleTunnelGatewayMsg (I2NPMessage * msg)
 	{		
-		TunnelGatewayHeader * header = (TunnelGatewayHeader *)msg->GetPayload ();
-		uint32_t tunnelID = be32toh(header->tunnelID);
-		uint16_t len = be16toh(header->length);
+		const uint8_t * payload = msg->GetPayload ();
+		uint32_t tunnelID = bufbe32toh(payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET);
+		uint16_t len = bufbe16toh(payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET);
 		// we make payload as new I2NP message to send
-		msg->offset += sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader);
+		msg->offset += I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE;
 		msg->len = msg->offset + len;
-		LogPrint ("TunnelGateway of ", (int)len, " bytes for tunnel ", (unsigned int)tunnelID, ". Msg type ", (int)msg->GetHeader()->typeID);
-		if (msg->GetHeader()->typeID == eI2NPDatabaseStore ||
-		    msg->GetHeader()->typeID == eI2NPDatabaseSearchReply)
+		auto typeID = msg->GetTypeID ();
+		LogPrint ("TunnelGateway of ", (int)len, " bytes for tunnel ", (unsigned int)tunnelID, ". Msg type ", (int)typeID);
+			
+		if (typeID == eI2NPDatabaseStore || typeID == eI2NPDatabaseSearchReply)
 		{
 			// transit DatabaseStore my contain new/updated RI 
 			// or DatabaseSearchReply with new routers
diff --git a/I2NPProtocol.h b/I2NPProtocol.h
index c0d98459..348632aa 100644
--- a/I2NPProtocol.h
+++ b/I2NPProtocol.h
@@ -18,7 +18,13 @@ namespace i2p
 	const size_t I2NP_HEADER_EXPIRATION_OFFSET = I2NP_HEADER_MSGID_OFFSET + 4;
 	const size_t I2NP_HEADER_SIZE_OFFSET = I2NP_HEADER_EXPIRATION_OFFSET + 8;
 	const size_t I2NP_HEADER_CHKS_OFFSET = I2NP_HEADER_SIZE_OFFSET + 2;
-
+	const size_t I2NP_HEADER_SIZE = I2NP_HEADER_CHKS_OFFSET + 1;
+	
+	// Tunnel Gateway header
+	const size_t TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET = 0;
+	const size_t TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET = TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET + 4;
+	const size_t TUNNEL_GATEWAY_HEADER_SIZE = TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET + 2;
+	
 #pragma pack (1)
 
 	struct I2NPHeader
@@ -77,13 +83,6 @@ namespace i2p
 		uint8_t toPeer[16];
 		uint8_t encrypted[512];
 	};
-
-	struct TunnelGatewayHeader
-	{
-		uint32_t tunnelID;
-		uint16_t length;
-	};		
-
 	
 #pragma pack ()	
 
diff --git a/TunnelEndpoint.cpp b/TunnelEndpoint.cpp
index 6f28b990..74fd0262 100644
--- a/TunnelEndpoint.cpp
+++ b/TunnelEndpoint.cpp
@@ -105,8 +105,8 @@ namespace tunnel
 				{
 					// this is not last message. we have to copy it
 					m.data = NewI2NPMessage ();
-					m.data->offset += sizeof (TunnelGatewayHeader); // reserve room for TunnelGateway header
-					m.data->len += sizeof (TunnelGatewayHeader);
+					m.data->offset += TUNNEL_GATEWAY_HEADER_SIZE; // reserve room for TunnelGateway header
+					m.data->len += TUNNEL_GATEWAY_HEADER_SIZE;
 					*(m.data) = *msg;
 				}
 				else