Using LRR (last receiver report) and DLRR (delay since last receive
report) in RTCP-XR (extended report) may enable you to measure roundtrip
propagation delay. Of course, two phones involved in a session must
undersatand and support the receiver report.
I know Telchemy (http://www.telchemy.com/) owns some patent on MOS voice
quality measurement, but not sure what is their scope of coverage.
Thanks,
Joon
>>
>> Does Linphone have a feature of calculating MOS (Measn Openion Score)
of a
>> voice call? If yes, how the score is reported, RTCP, SNMP or ...?
>
>As I know there is no satisfactory way to calculate MOS on the fly.
>
> * Originally proposed method (see ITU-T Rec. P.800) requires
>absolutely unsuitable conditions (such as specially-equipped studios,
etc)
>
> * There is also PESQ (ITU-T Rec. P.862) which requires both reference
>and degraded speech samples (as I suppose, this is also unsuitable for
>the real-time quality estimation).
>
> * Last chance is an E-model (ITU-T Rec. G.107) which originally was
>proposed as quality estimation model for the circuit switching networks.
> Some of parameters of this model (such as one-way delay) cannot be
>calculated without additional measurements.
>
>I'd like to hear if somebody knows another ways to calculate speech
>quality or knows how to implement in real-time VoIP application some of
>methods proposed below.
>
>Also I'm not sure but it seems that PESQ and E-model are patented.
>
>--
>WBR, Roman Imankulov
>[EMAIL PROTECTED]
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