Cisco Cisco MGX-FRSM-HS2 B Serial Frame Service Module Libro blanco
White Paper
Copyright © 2010 Cisco Systems, Inc. This document is Cisco Public Information.
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Figure 15. Service Monitor Sensor Report (Part 2)
Figure 16. Service Monitor Streams and Call Record
Please refer to the Cisco Unified Service Monitor 2.2 Deployment Best Practices in regard to Service Monitor
integration with NAM at
http://www.cisco.com/en/US/prod/collateral/netmgtsw/ps6491/ps6705/ps6536/white_paper_c07-554560.html
.
Summary
In today’s complex multimedia networks, the ability to measure the quality experienced by end users is critical. By
providing visibility into the quality of VoIP traffic, NAM 4.1 significantly enhances the ability of IT personnel to detect,
isolate, and troubleshoot VoIP problems. Its real-time monitoring and alerting capabilities facilitate a proactive
approach to monitoring user experience, which helps increase end-user satisfaction.
Glossary
MOS
The computed Mean Opinion Score for the minute interval. MOS is computed according to ITU-T G.107 E-Model
every three seconds. The reported MOS is the average of all three second scores for the minute. The minimum
stream duration to compute MOS is one second of media flow.
every three seconds. The reported MOS is the average of all three second scores for the minute. The minimum
stream duration to compute MOS is one second of media flow.
Packets lost
The count of aggregate packets lost due to network transmission during the reporting period. This is computed
based on observed RTP sequence number analysis.
based on observed RTP sequence number analysis.
Jitter
The RFC 3550 jitter value in milliseconds. This value is a smoothed metric and may not be adequately indicative of
problems given short and sudden spikes in jitter. This value should be a good description of the jitter given a
uniform and constant distribution of jitter events.
problems given short and sudden spikes in jitter. This value should be a good description of the jitter given a
uniform and constant distribution of jitter events.
Percent network loss
The percentage of packets dropped by the network on the way to the destination address.
Adjusted packet loss
The percentage of packets lost due to high jitter. This value is computed based on a reference jitter buffer with a
fixed length play-out delay. It is not affected by network loss.
fixed length play-out delay. It is not affected by network loss.
SOC
Seconds of concealment. The number of seconds during which any impairment was experienced. Impairment can
be due to network loss or high jitter. If just one packet is lost during the entire reporting interval, this value should be
1. If each second of the reporting period experiences at least one lost packet then this value should be 60.
be due to network loss or high jitter. If just one packet is lost during the entire reporting interval, this value should be
1. If each second of the reporting period experiences at least one lost packet then this value should be 60.
SSOC
Severe seconds of concealment. The number of seconds during which severe impairment was experienced. Severe
impairment is defined by packet loss greater than or equal to 5 percent, including both network loss and loss due to
jitter buffer discards.
impairment is defined by packet loss greater than or equal to 5 percent, including both network loss and loss due to
jitter buffer discards.