An application server running an SNA application includes a TN3270 server. Performance of the application server is enhanced by relocating away from the application server the conversion of data between ASCII and EBCDIC, as well as command scanning and packaging. The relocating can take the form of, for example, a browser plug-in at the client or elsewhere. In addition, the client is able to carry on communications with the application server over a standard port by logically situating a communication server between the client and the application server. The client communicates with the communication server over the standard port, while the communication server forwards the communications to the application server over a non-standard port.