Cisco Systems OL-21011-01 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
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 Monitoring the Voice Quality of Calls, 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 for the Cisco Unified IP Phones 7962G and 7942G 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
		These codecs for the Cisco Unified IP Phones 7961G/G-GE and 7941G/G-GE provide the
		following maximum MOS LQK score under normal conditions with no frame loss:
		•	G.711 gives 4.5
		• G.729 A /AB gives 3.7
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.

	Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.0 (SCCP and SIP)
OL-21011-01		8-13