IMHO ping tests are never a good solution to test network throughput. And certainly not when performing them from the router or switch. Reasons for this are:

1: ICMP is often processed from the control plane and will hence provide an incorrect picture of the actual performance. The TCP/UDP performance using CEF is generally much better.

2: In MPLS networks, providers sometimes configure ICMP throttling. The result of this can be that one gets the incorrect impression that the link has packet loss.

The best way to test is using a special application like iPerf/Jperf (poor man's solution) or Chariot for the more established ones. When you want accurate results, it is obvious that such tests should not be run between network devices but rather among powerful servers or workstations. Linux is better suited for this purpose because it delivers higher (and more constant) performance than Windows.

Naturally such a test is more difficult to set up but testing from the switch or router really doesn't tell you much more than whether there is connectivity or not. No conclusions can be drawn from it regarding the performance.

regards,

Leo