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User Guide for the Cisco Network Analysis Module (NAM) Traffic Analyzer, 5.0
OL-22617-01
Chapter 3 Monitoring and Analysis
Media
RTP Stream Stats Details
This table shows the per-interval stats calculated by NAM at each interval. The columns of the tables are:
• Report Time: time when the stats were calculated. This is the end time of the interval.
• Report Duration: the stream duration during the report interval.
• Worst MOS: the lowest score of the stream among 3-second MOS score. NAM internally evaluates
the MOS value of the stream every 3 seconds. This is the lowest score among them.
• Average MOS: average score of the 3-second score values during the duration of the stream in the
interval. This value is used in deriving the Duration Weighted MOS value in NAM.
• Jitter: variation of packet arrival time compare to the expected time.
• Actual Packet Loss percentile: percentile of packets that are not seen by NAM.
• Adjusted Packet Loss percentile: percentile of packets that include the actual packets lost an packets
that had arrived too late to get into buffer prior to paying back at the endpoint.
• Concealment Seconds: number of seconds in which the NAM sees packet loss.
• Severe Concealment Seconds: number of seconds in which the NAM detected more 5 percent of
packet loss.
• Packets: total packets NAM have seen for the interval.

Monitoring RTP Streams

To monitor the RTP streams, choose Analyze > Media > RTP Streams. You can also arrive at this page
by:
• From the RTP Conversation table, clicking on a specific stream
• From the Call Detail window, clicking on the stream that is associated with the call
On this screen, at least one of the following is required: Site, data source, or VLAN.
The five charts available on this screen are:
• RTP Strea ms: Number of streams that fall in the quality bands of excellent, good, fair, and poor
during the selected interval.
• Top N Source End Points: Endpoints that generated the lowest duration weighted MOS during the
selected interval.
• Top N Destination Endpoints: Endpoints that experienced the lowest duration weighted MOS
during the selected interval.
• Top N RTP str ea ms: RTP streams that have the lowest duration weighted MOS during the selected
interval.
• Top N RTP streams by Adjusted Packet Loss: RTP streams that have the highest overall adjusted
packet loss percent during the selected interval.
Voice Call Statistics
To monitor voice quality, choose Analyze > Media > Voice Call Statistics. The charts will provide an
overview of voice quality.
The charts available are: