diff --git a/clib/tcpnet.cpp b/clib/tcpnet.cpp
index 2afbe14..b14c2e7 100644
--- a/clib/tcpnet.cpp
+++ b/clib/tcpnet.cpp
@@ -71,10 +71,7 @@ int TcpNet::server(int portno, const std::function<std::pair<bool, std::string>(
 			shutdown = response.first;
 			std::string response_str = response.second;
 
-			auto response_len = response_str.size();
-			auto n = write(newsockfd, response_str.c_str(), response_len);
-			if (n < 0 || response_len != n)
-				error("ERROR writing to socket");
+			write_to_socket(newsockfd, response_str);
 
 			requests_processed++;
 		}
@@ -134,10 +131,20 @@ std::string TcpNet::client(const std::string &address, int portno, const std::st
 	return response[0];
 }
 
+
 std::string TcpNet::read_from_socket(int sockfd) {
 	char buffer[TCPNET_BUFFER_SIZE];
 	std::string request;
 
+	// read length header
+	unsigned long long bytesLen = 0;
+	if (USE_LENGTH_HEADER) {
+		long n = read(sockfd, &bytesLen, sizeof(bytesLen));
+		if (n != 0 && n != sizeof(bytesLen))
+			error("ERROR reading length header failed");
+	}
+
+	// read data
 	long n;
 	do {
 		memset(buffer, 0, TCPNET_BUFFER_SIZE);
@@ -153,7 +160,7 @@ std::string TcpNet::read_from_socket(int sockfd) {
 
 		std::string part{buffer};
 		request.append(part);
-	} while (n == TCPNET_BUFFER_SIZE - 1);    // TODO what if data exactly of this size
+	} while ((USE_LENGTH_HEADER && n < bytesLen) || n == TCPNET_BUFFER_SIZE - 1);    // TODO what if data exactly of this size
 
 	return request;
 }
@@ -162,6 +169,16 @@ void TcpNet::write_to_socket(int sockfd, const std::string &str) {
 	const char *buffer = str.c_str();
 	int pos = 0;
 	long n;
+
+	// write length header
+	unsigned long long bytesLen = str.length(); 
+	if (USE_LENGTH_HEADER) {
+		n = write(sockfd, &bytesLen, (int) sizeof(bytesLen));
+		if (n < 0)
+			error("ERROR writing size number to socket");
+	}
+	
+	// write data
 	do {
 		n = write(sockfd, buffer + pos, (int) (str.length() - pos));
 		if (n < 0)
diff --git a/clib/tcpnet.h b/clib/tcpnet.h
index 4adab26..f153d27 100644
--- a/clib/tcpnet.h
+++ b/clib/tcpnet.h
@@ -17,6 +17,7 @@ public:
 	[[nodiscard]] std::vector<std::string> client(const std::string &address, int portno, const std::vector<std::string> &requests) const;
 
 private:
+	static const bool USE_LENGTH_HEADER = true;
 	static std::string read_from_socket(int sockfd) ;
 	static void write_to_socket(int sockfd, const std::string &str) ;
 };