This utility can be used to monitor the data flowing on a TCP connection. tcpmon is used by placing it in-between a client and a server. The client is made to connect to tcpmon, and tcpmon forwards the data to server along-with displaying it in its GUI.
The client will connect to the Local Port on the host where tcpmon is running. The address of the server should be specified in Server Name and Server Port. Information captured for each connection is displayed in a tabbed panel identified by the local port of the connection.
tcpmon is authored by Inderjeet Singh (http://singhinderjeet.com/) and is hosted on Google code at http://code.google.com/p/tcpmon. tcpmon is a free software, and its source-code is available under the open-source Apache 2.0 License.