ActiveXperts Network Monitor 2015 proactively manages network servers, devices, databases and more.

Microsoft Resource Kits - Windows 2003 Resource Kit

Qtcp.exe  (Windows 2003 Resource Kit)

The Window Server 2003 Resource Kit is a set of tools that system administrators and engineers use to manage or support a Windows Server 2003 system. Use it to streamline management tasks such as troubleshooting operating system issues, managing Active Directory, configuring networking and security features, and automating application deployment.
This command-line tool measures end-to-end network service quality. Qtcp sends a sequence of test packets through a network, then reports on the queuing delay experienced by each packet. Packets that do not arrive at the destination are recorded as dropped packets. This tool can be used on either a production network or a controlled test network.