Hi, I'm developing a TCP-Client using boost::asio and discovered that ACKs to responses from the server are sent with some delay (~200ms) and I get the data not before this ACK has been sent. When I disable nagle in registry as described by Microsoft it works fine. (See: http://support.microsoft.com/kb/823764) To avoid those registry hacks I want to find another way to get rid of this latency. I'm already using blocking sockets as suggest in above document. I also tried to set the no_delay option but this has no effect at all. boost::asio::ip::tcp::no_delay option(true); socket.set_option(option); == Code Snippets == I use the boost asio library as follows: // open connection (from synchronous TCP daytime client example) boost::asio::io_service io_service; tcp::resolver resolver(io_service); tcp::resolver::query query(ipaddress, port); tcp::resolver::iterator endpoint_iterator = resolver.resolve(query); tcp::resolver::iterator end; boost::system::error_code error = boost::asio::error::host_not_found; while (error && endpoint_iterator != end) { socket.close(); socket.connect(*endpoint_iterator++, error); } // send some data boost::asio::write(socket, boost::asio::buffer(package, size)); // reception is done inside a thread while(true) { // receive data size_t length = socket.read_some(boost::asio::buffer(resp), error); if (error == boost::asio::error::eof) { // Connection closed cleanly by peer. // ... do sth. } else if (error) { // Some error has happened // ... do sth. } // ... process received data and notify main thread to send the next piece of data } ======= Thank you for all suggestions. Tobias