Shortfall
GlobalRoute combines probe results into a composite figure called “shortfall”
- Shortfall incorporates both latency and loss
Computation
- Shortfall is scaled between 0 and 100
- Latency greater than 1500ms (configurable) is considered loss
- For each routable, each set of scanpoint probes is scored using their weights to determine an average
- Latency is treated linearly, and then loss is incorporated
- For each instance of packet loss there is an additional penalty in the shortfall computation
- Data is smoothed to minimize the impact of spikes and transient noise
There is an effort to model shortfall to actual performance