The maximum acceptable limits for Network Utility are:
Packet loss -less than 0.3%
Jitter rate - less than 20
Latency - less than 120 ms
Bufferbloat grades
To identify good vs bad bufferbloat, the speed test applies grades as follows. Milliseconds (ms) refers to an increase in a measure of round trip delay when your connection is fully utilized.
A+: Less than 5 ms (average of down bloat and up bloat)
A: Less than 30 ms
B: Less than 60 ms
C: Less than 200 ms
D: Less than 400 ms
F: 400 ms +
Note:
There is no E grade for bufferbloat.