Over the past several months there have been a number of new features and graphs added to the AMP data graphs. As of early March, the AMP mesh now supports user initiated path measurement; please see the traceroute request form at http://watt.nlanr.net/active/cgi-bin/tr-request.cgi.
Help and additional information are now available for each graph by clicking the appropriate "I" icon, located by each graph. Jitter graphs were recently added to the daily graphs page.
Each of the daily graphs is discussed below; an excellent example of the graphs working together can be seen on these graphs from: Wed Dec 19 2001.
All graphs are displayed in US Pacific Time (West Coast USA). (A project is underway which will allow the user to select a time zone.)
Round Trip Time (RTT) - shows the round trip time from the source to the destination and back again. Clicking the [routes] link reveals the path from the source to the destination, (from there, the reverse path link shows the reverse path).
Route graphic - shows, in visual form, the route from the source to the destination, and the IP Hop Count. Route information is collected from a traceroute command, executed approximately every 10 minutes. By choosing a time (i.e., a position on the x-axis) and moving vertically up the graphic, you cross each hop in the path at that time. The browser's status line will show the DNS name for that hop. Clicking on the graphic will take you to the traceroute information for that path and time.
Event bar plot - at the bottom of the route graphic (discussed above) you may find colored horizontal bars. The event bar time frame matches that of the route graphic immediately above it. These bars indicate the duration of network events that we have been advised of from Abilene,vBNS, or StarTap (or, in some cases our own activities). Clicking on the bar will take you to the text of the notification. They are color-coded as to the source of the event.
Jitter graph - shows the variation in RTT between adjacent measurements. Clicking the [routes] link reveals the path from the source to the destination, (from there, the reverse path link shows the reverse path).
Distribution plot - shows the frequency of different RTTs.
Packet loss plot - shows the percentage loss in each 5 minute interval over the measured path. Clicking the [routes] link reveals the path from the source to the destination, (from there, the reverse path link shows the reverse path).
Please note: For several of the graphs both the x-axis and the y-axis are scaled to match the data. Therefore, it is important to take care when comparing graphs over different paths. For additional information and tips, please see each help icon.