Cisco Systems 8961 manual Voice-Quality Metrics, Mos Lqk, Cisco Unified IP Phone uses, 10-12

Chapter 10 Viewing Model Information, Status, and Statistics on the Cisco Unified IP Phone

Status Menu

Table 10-5 Call Statistics Items for the Cisco Unified Phone (continued)

Item	Description
Avg Jitter	Estimated average RTP packet jitter (dynamic delay that a packet
	encounters when going through the network), in milliseconds, observed
	since the receiving voice stream was opened.
Max Jitter	Maximum jitter, in milliseconds, observed since the receiving voice
	stream was opened.
Rcvr Discarded	Number of RTP packets in the receiving voice stream that have been
	discarded (bad packets, too late, and so on).
	Note The phone will discard payload type 19 comfort noise packets
	that are generated by Cisco Gateways, which will increment this
	counter.
Rcvr Lost Packets	Missing RTP packets (lost in transit).
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 eight-second interval of the voice stream. For more
	information, see the “Monitoring the Voice Quality of Calls” section on
	page 12-16.
	Note 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.729 A /AB gives 3.7
MOS LQK Version	Version of the Cisco proprietary algorithm used to calculate MOS LQK
	scores.
Cumulative 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).

	Cisco Unified IP Phone 8961, 9951, and 9971 Administration Guide for Cisco Unified Communications Manager 8.5 (SIP)
10-12	OL-20861-01