The results were broadly equivalent which suggests that to a first approximation the use of ICMP based tools provide reliable measurements. The use within the HEP community of PingER is well established. PingER data is stored locally to allow Web-based access to provide an analysis of packet loss, rtt and the frequency distribution of rtt measurements in both graphical and tabular format. There is clearly a danger that through ICMP rate limiting or ping discard policy that this approach will either give invalid results or no results at all. However this offers no guarantees in the future.
Surveyor measures the performance of the Internet paths among participating organizations.
The project is also developing methodologies and tools to analyze the performance data. One-way delay and packet loss are measured for each of the paths by sending time stamped test packets from one end of the specified path to the other. The one-way delay is computed by subtracting the timestamp in the packet from the time of arrival at the destination machine. The test packets are sent as a Poisson stream, usually at an average rate of two packets per second. The values are accurate to within 50 microseconds.