Mean Opinion Scores And Codecs - Cisco IP Phone 6851 Administration Manual

Voice Quality Reporting

Mean Opinion Scores and Codecs

The voice quality metrics use Mean Opinion Score (MOS) to rate the quality. A MOS rating of 1 is the lowest
quality; a MOS rating of 5 is the highest quality. The following table gives a description of the codecs and
MOS scores. For other codecs, the phone does not send the SIP Publish message.
Codec
G.711
(A-law
and
u-law)
G.729A
G. 7 29AB
Configure Voice Quality Reporting
You can enable voice quality reporting on the phone with the web interface. Each extension on a phone has
a separate voice quality report. For each extension on the phone, use the corresponding Voice Quality Report
Address field to configure the generation of voice quality report.
Procedure
Step 1
On the Phone Web page, select Admin Login > advanced > Voice > Ext x.
Where:
• Ext x = the extension number on the phone
Step 2 In SIP Settings, enter a value in the Voice Quality Report Address x field. You can enter either a domain
name or an IP address in this field.
You can also add a port number along with the domain name or an IP address in this field. If you do not enter
a port number, the value of the SIP UDP Port (5060) is used by default. If the collector server URL parameter
is blank, a SIP PUBLISH message is not sent out.
Step 3 Click Submit All Changes.
Cisco IP Phone 6800 Series Multiplatform Phones Administration Guide
224
Complexity and Description
Very low complexity.
Supports uncompressed 64
kbps digitized voice
transmission at one to ten 5
ms voice frames-per-packet.
This codec provides the
highest voice quality and
uses the most bandwidth of
any of the available codecs.
Low to medium complexity.
Contains the same reduced
complexity modifications
present in the G.729A.
MOS
A minimum value of 4.1 indicates good
voice quality.
A minimum value of 3.5 indicates good
voice quality.
A minimum value of 3.5 indicates good
voice quality.
Minimum Call Duration for
Valid MOS Value
10 seconds
30 seconds
30 seconds