[asterisk-users] Calculating R Factor and MOS metrics for VoIP

[Klaus Darilion]

Am 08.03.2010 11:10, schrieb mosbah.abdelkader:
> Hello All,
>
>
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> MOS and R factor are the two QoS parameters used to estimate VoIP call
> quality.
>
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> I have found that they are calculated from other metrics like jitter,
> latency, packet loss,...etc. But, haven't found any formula or
> arithmetic rule to calculate them.

IMO most of these calculations are crap, because you can not tell the 
voice quality just based on network statistics.

The perceived quality also heavily depends on the playback algorithms, 
e.g. jitter buffer (static? dynamic? size? FFT for faster playback ...) 
and error correction and error concealment.

AFAIK all the available VoIP MOS calculations operate on packet layer, 
thus they do not include the playback characteristics.

regards
klaus

>
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> Do you have an idea about their formulas or an open source that
> calculates them. Is it possible to interpret them from wireshark.
>
>
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> Thanks.
>
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>
>
>
> --
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>
> http://www.55a.net/
>