Cisco Systems OL-14625-01 manual Voice Quality Metrics

Chapter 8 Monitoring the Cisco Unified IP Phone Remotely

Streaming Statistics

Table 8-5	Streaming Statistics Area Items (continued)
Item		Description
Latency1		Estimate of the network latency, expressed in milliseconds. Represents a running average
		of the round-trip delay, measured when RTCP receiver report blocks are received.
Max Jitter		Maximum value of instantaneous jitter, in milliseconds.
Sender Size		RTP packet size, in milliseconds, for the transmitted stream.
Sender Reports Received1		Number of times RTCP Sender Reports have been received.
Sender Report Time		Last time at which an RTCP Sender Report was received.
Received1
Rcvr Size		RTP packet size, in milliseconds, for the received stream.
Rcvr Discarded		RTP packets received from network but discarded from jitter buffers.
Rcvr Reports Received1		Number of times RTCP Receiver Reports have been received.
Rcvr Report Time Received1		Last time at which an RTCP Receiver Report was received.
Voice Quality Metrics
MOS LQK		Score that is an objective estimate of the mean opinion score (MOS) for listening quality
		(LQK) that rates from 5 (excellent) to 1 (bad). This score is based on audible concealment
		events due to frame loss in the preceding 8-second interval of the voice stream. For more
		information, see the “Monitoring the Voice Quality of Calls” section on page 9-15.
		The MOS LQK score can vary based on the type of codec that the Cisco Unified IP Phone
		uses.
Avg MOS LQK		Average MOS LQK score observed for the entire voice stream.
Min MOS LQK		Lowest MOS LQK score observed from start of the voice stream.
Max MOS LQK		Baseline or highest MOS LQK score observed from start of the voice stream.
		These codecs provide the following maximum MOS LQK score under normal conditions
		with no frame loss:
		•	G.711 gives 4.5
		•	G.722 gives 4.5
		•	G.728/iLBC gives 3.9
		• G.729 A/AB gives 3.8
MOS LQK Version		Version of the Cisco proprietary algorithm used to calculate MOS LQK scores.
Cmltve Conceal Ratio		Total number of concealment frames divided by total number of speech frames received
		from start of the voice stream.
Interval Conceal Ratio		Ratio of concealment frames to speech frames in preceding 3-second interval of active
		speech. If using voice activity detection (VAD), a longer interval might be required to
		accumulate 3 seconds of active speech.
Max Conceal Ratio		Highest interval concealment ratio from start of the voice stream.
Conceal Secs		Number of seconds that have concealment events (lost frames) from the start of the voice
		stream (includes severely concealed seconds).
Severely Conceal Secs		Number of seconds that have more than 5 percent concealment events (lost frames) from
		the start of the voice stream.

1. When the RTP Control Protocol is disabled, no data generates for this field and thus displays as 0.

	Cisco Unified IP Phone 7962G and 7942G Administration Guide for Cisco Unified Communications Manager 6.1
OL-14625-01		8-13