The network layer was unable to connect a socket. Check the following: 1) The machine is connected to the network. 2) The socket layer is properly initialized. 3) The correct host machine and port were specified. 4) The host server is running normally and listening on the correct port. 5) The host machine is listening for the proper socket type (TCP/IP vs. UDP). 6) If the client_port option was used, verify that there are no firewall restrictions on the use of the port. 7) If the device has a limit on the number of open sockets, verify that the limit has not been reached. 8) There are enough system resources available. Free up system resources if they are running low.