Resolution
CAR generates Quality of Service reports. To qualify the data presented in those reports, CAR uses predefined values that are set about voice quality. Specify the value ranges that are good, acceptable, fair, and poor for jitter, latency, and lost packets. If a call does not satisfy any of the criteria set for any of the three voice-quality categories, it receives a classification of NA (not applicable).
Enter NA to ignore the values of a parameter. For example, a QoS parameter such as jitter, has NA, and the QoS is defined as good. This means that the QoS depends only on the values of latency and lost packets. All three parameters cannot have NA as values. Infinity designates the maximum value that is available for any parameter. If you specify a rule where a jitter value from 500 to Infinity is considered poor, a call with jitter greater than 500 receives a classification of poor.
The Quality of Service (QoS) categorizations are configured in Call Details Record Analysis and Reporting (CAR) under Report Config > Define QoS.
For a single row in the Define QoS parameter, all of the conditions in that row must be true for calls to be classified in the QoS category specified. So, if lost packets are set from 0-1%, jitter is set from 0 to 15%, and latency is set from 0-200% for QoS, only calls meeting all three of these criteria are classified by that row. If classification based on only one of the conditions is desired, NA is entered in the fields for the other two conditions in the row.
Note: QoS reports also show NA if there are H.323 gateways.
This is described in more detail in the Defining the Quality of Service (QoS) Values section of CAR Report Configuration.
Also refer, In "Quality of Service (QoS) based on Gateway" in ART, why are the origination Call Management Record (CMR) fields empty for H.323? section of the document CallManager Issue Resolution with CDR and ART FAQ
