User's Manual  940  Document #: LTRT-10632 
 
  Mediant 800B Gateway & E-SBC 
  Minor Threshold (Yellow): Lower threshold that indicates changes from Green or 
Red to Yellow. 
  Major Threshold (Red): Higher threshold that indicates changes from Green or 
Yellow to Red. 
The device also uses hysteresis to determine whether the threshold has indeed being 
crossed. Hysteresis defines the amount of fluctuation from the threshold in order for the 
threshold to be considered as crossed (i.e., change in color state). Hysteresis is used to 
avoid false reports being sent by the device. Hysteresis is used only for threshold crossings 
toward a lesser severity (i.e., from Red to Yellow, Red to Green, or Yellow to Green).  
The following example is used to explain how the device considers threshold crossings. 
The example is based on the ASR of a call, where the Major threshold is configured to 
70%, the Minor threshold to 90% and the hysteresis for both thresholds to 2%: 
Figure  59-4: Example of Threshold Crossings (ASR) 
 
Table  59-2: Threshold Crossings based on Threshold and Hysteresis 
Threshold Crossing  Calculation 
Threshold based on 
Example 
Green to Yellow (Minor alarm)  The change occurs if the measured metric 
crosses the configured Minor threshold only 
(i.e., hysteresis is not used). 
90% 
Green to Red (Major alarm)  The change occurs if the measured metric 
crosses the configured Major threshold onl
(i.e., hysteresis is not used). 
70% 
Yellow to Red (Major alarm)  The change occurs if the measured metric 
crosses the configured Major threshold only 
(i.e., hysteresis is not used). 
70% 
Red to Yellow (Minor alarm)  The change occurs if the measured metric 
crosses the configured Major threshold with 
hysteresis. 
72% (i.e., 70 + 2) 
Red to Green (alarm cleared)  The change occurs if the measured metric 
crosses the configured Minor threshold with 
hysteresis. 
92 (i.e., 90 + 2) 
Yellow to Green (alarm 
cleared) 
The change occurs if the measured metric 
crosses the configured Minor threshold with 
hysteresis. 
92 (i.e., 90 + 2)