[asterisk-users] Measuring voice quality with Asterisk

[Klaus Darilion]

Matt Riddell schrieb:
> On 31/08/09 8:47 PM, Klaus Darilion wrote:
>>
>> Olle E. Johansson schrieb:
>>> 27 aug 2009 kl. 11.24 skrev Klaus Darilion:
>>>
>>>> Hi!
>>>>
>>>> I want to use Asterisk as load generator to test quality degradation
>>>> with increased load (e.g. testing other SIP equipment or IP-links).
>>>>
>>>> Is anybody aware of such a setup with Asterisk - is it possible to get
>>>> RTP statistics out of Asterisk (e.g. jitter, packet loss,
>>>> reordering ...)?
>>>>
>>> Check the RTPAUDIOQOS variable documented in channelvariables.txt :-)
>>>
>>> You propably want to catch it in the "h" extension and put it in the
>>> CDRs or something.
>> That is good for after-call statistics. I am currently trying to get
>> real-time stats.
> 
> Do the rtcp stats give out info over the manager?  Maybe you could use 
> those?  They definitely come up in the console if enabled.

Yes, those events are reported over AMI.

In my first tests I connected via AMI and fetched a channel list, and 
then for each channel I fetched CHANNEL(qos,audio,all). Of course that 
did not scaled. Thus, I wonder if reading RTP events scale.

Further I found out that the RTCP events do not have a reference to a 
channel. Thus, it is not possible to find out which channel 
received/sent this RTCP packet.

As the QoS settings are also stored within the rtp channel structure, I 
was thinking of adding some functionality to rtp handler to export QoS 
stats every few seconds and when the call ends.

regards
klaus

>