Please take a look at: http://www.ripe.net/data-tools/stats/ttm/test-traffic-measurement-service
Note that what they provide is: * NTP-server, the test-boxes can act a stratum 1 server for the machines on your network, providing time-stamps with an accuracy of 10 microseconds. Thanks, Nalini Elkins Inside Products, Inc. (831) 659-8360 www.insidethestack.com
