I recently ran across the Microsoft Port Reporter. The Port Reporter tool runs as a service on computers that are running Windows Server 2003, Windows XP, and Windows 2000. The tool logs TCP and UDP port activity.
The Port Reporter Parser tool is a log parser for Port Reporter log files. Port Reporter Parser has many advanced features that can help analyze Port Reporter log files.
PortQry is a related Microsoft tool. This is a TCP/IP connectivity testing utility that is included with the Microsoft Windows Server 2003 Support Tools. Version 2 includes all the features and functionality of the earlier version and has new features and functionality and is available from the Microsoft Download Center.This tool permits you to track activity on a single port or on all ports that are used by a specified process.