All, Below is the client request code which makes a CONNECT request to remote SERVER (having IP & PORT#) but gives error code during send() process - --- #include <iostream> #include <string> #include <boost/asio.hpp> namespace opp = boost::asio::ip; struct PacketFormat { unsigned short length; //Length int sequenceNumber; }; int main(int argc, char* argv[]) { std::string port = "8000"; std::string hostname = "X.X.X.X"; boost::asio::io_service io_service; opp::tcp::resolver resolver(io_service); opp::tcp::resolver::query query(hostname, port); opp::tcp::resolver::iterator iter = resolver.resolve(query); opp::tcp::resolver::iterator end; // End marker. // Looking for a successful endpoint connection opp::tcp::socket socket(io_service); boost::system::error_code error = boost::asio::error::host_not_found; while (error && iter != end) { socket.close(); socket.connect(*iter++ , error); } if (error) throw boost::system::system_error(error); std::cout << "Connected ..Thanks!! \n" << std::endl; PacketFormat pf; // where PacketFormat is struct defined pf.length = 236; pf.sequenceNumber = 2; std::cout << "Sending Logon Message.. . ..!! \n" << std::endl; std::size_t n = opp::tcp::socket::send(iter, boost::asio::buffer(&pf)); if (n < 0) std::cerr << "ERROR writing to Server .. . ..\n" << std::endl; std::cout << "Logon Message Sent.. . ..Thanks!!\n" << std::endl; if (n < 0) std::cerr << "ERROR writing to Server .. . ..\n" << std::endl; std::cout << "Logon Message Sent.. . ..Thanks!!\n" << std::endl; return 0; } __ The error message obtained is - -- # g++ testclient.cpp -o testclient -lboost_system -lboost_thread testclient.cpp: In function âint main(int, char**)â: testclient.cpp:42: error: no matching function for call to âbuffer(PacketFormat*)â /usr/local/include/boost/asio/buffer.hpp:704: note: candidates are: boost::asio::mutable_buffers_1 boost::asio::buffer(const boost::asio::mutable_buffer&) /usr/local/include/boost/asio/buffer.hpp:717: note: boost::asio::mutable_buffers_1 boost::asio::buffer(const boost::asio::mutable_buffer&, size_t) /usr/local/include/boost/asio/buffer.hpp:733: note: boost::asio::const_buffers_1 boost::asio::buffer(const boost::asio::const_buffer&) /usr/local/include/boost/asio/buffer.hpp:746: note: boost::asio::const_buffers_1 boost::asio::buffer(const boost::asio::const_buffer&, size_t) /usr/local/include/boost/asio/buffer.hpp:762: note: boost::asio::mutable_buffers_1 boost::asio::buffer(void*, size_t) /usr/local/include/boost/asio/buffer.hpp:772: note: boost::asio::const_buffers_1 boost::asio::buffer(const void*, size_t) __ Please help for L#42 "tcp::socket::send()" proper call. I believe above code fine apart from L#42 error. Thanks!!