The speed reported is more like an OC-6 line, six OC-1 channels. But the speed test is only accurate if you have a testing server fast enough to keep up with a big pipe to handle the incoming connection.
Anyway nice throughput! Are you one of the admins running the test on the backbone. I do that all the time, its fun when I have nothing else to do . I can't punch out the OC-192 lines though, I need to find a server fast enough to run the test . One of our data centers just got a new Juniper T640 router.