Mean Opinion Score (MOS) in SolarWinds VNQM

MOS is an industry standard measure of call quality expressed on a scale of increasing perceived quality, from one to five. VoIP and Network Quality Manager reports MOS as computed by a standard International Telecommunications Union (ITU) algorithm involving the codec for your VoIP network and values of latency, jitter, packet loss, and MOS advantage factor. Jitter, latency, and packet loss are variable quantities that are measured by VoIP and Network Quality Manager in real time. Generally, MOS reflects call quality as shown in the following table.

Call quality	MOS
Very satisfied	4.3-5.0
Satisfied	4.0-4.3
Some users satisfied	3.6-4.0
Many users dissatisfied	3.1-3.6
Nearly all users dissatisfied	2.6-3.1
Not recommended	1.0-2.6

Both the MOS advantage factor and the codec algorithm are selected for your specific network on the VoIP and Network Quality Manager Settings page. The following table provides guidance for how the advantage factor is determined for your application.

Communication system type examples	Maximum advantage factor value
Conventional wired network	0
Wireless network within a building	5
Outdoor wireless network (cellular phones)	10
Remote communications by satellite	20

For more information about MOS calculations, see the ITU-T Recommendation G.107.

For more information about codec algorithms, see Jitter in SolarWinds VNQM.

For more information about VoIP and Network Quality Manager settings, see Configure SolarWinds VNQM settings.