SysInternals have released a new utility: PsPing.

PsPing is a command-line utility for measuring network performance. In addition to standard ICMP ping functionality, it can report the latency of connecting to TCP ports, the latency of TCP round-trip communication between systems, and the TCP bandwidth available to a connection between systems. Besides obtaining min, max, and average values in 0.01ms resolution, you can also use PsPing to generate histograms of the results that are easy to import into spreadsheets.

You can get it from SysInternals.