On 2018-02-14 12:21 PM, Alex Balashov wrote:
Hi Richard,

On Wed, Feb 14, 2018 at 08:18:11AM -0500, Richard Fuchs wrote:

On 2018-02-14 02:44 AM, Alex Balashov wrote:
Okay, so after having a spelunk through the source code, I have the
impression that this MOS / quality analysis functionality is limited
solely to feedback off RTCP supports.

I was under the impression from the documentation that RTPEngine does
some stream analysis of its own, although in fairness, the documentation
does not explicitly make this claim or the contrary one way or another.
It does gather some stats about the media streams on its own (even more so
with the extended transcoding capabilities now), but at least one component
of the MOS calculation (latency) depends on RTCP being provided by the RTP
clients, so without that, no MOS score can be produced.
Which statistics can RTPEngine compute over the stream on its own? Since
I saw no metrics whatsoever for the B leg, I assumed none. I was running
mr5.5.3 however. Does this differ in 6+?

It keeps track of packet and octet counts. With transcoding engaged for a call, it also keeps track of packet loss and duplications. It could calculate jitter, but doesn't currently do so.

Also — I'm sure the question has been asked before — can RTPEngine send
its own RTCP sender/receiver reports?

My testing setup was:

    Phone --> Kamailio+RTPEngine --> Kamailio+RTPEngine --> Carrier
                (where tinkering        (ITSP
                was happening)

Is there a way to turn on backward RTCP feedback from #3 back to #2?

Not currently, but we may offer that capability in the future, especially to support video in an RTP/AVP to (S)AVFP bridging scenario.


Kamailio (SER) - Users Mailing List

Reply via email to