Wireshark-dev: Re: [Wireshark-dev] Voice (RTP stream) quality - mos, delay, bandwidth, ...

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Thu, 01 Nov 2007 10:45:20 -0700

daniel zhang wrote:

1. MOS

Voice quality was traditionally reported as a Mean Opinion Score (MOS) on a scale from 1-5 where 1 is the lowest and 5 the highest. I am not an expert on this but I think probably we could add the MOS into Ethereal.

At least according to the Wikipedia article on the Mean Opinion Score:

	http://en.wikipedia.org/wiki/Mean_Opinion_Score

the score comes from people listening to particular phrases and giving their 1-to-5 rating of the quality of the sound, not from a calculation you could perform on a raw digital signal. That means Wireshark (the new name for the program that used to be called "Ethereal") couldn't calculate the MOS for a given voice sample (at least not without a plugin that connects to a number of user's machines, plays the sample to the user, asks them for their rating, and then averages the results; I don't know whether that could be done in a way that conforms to ITU-T Recommendation P.800).