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Kanuri, Seshu (Company IT) wrote:
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<pre wrap="">Iain Barker Wrote:
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<pre wrap="">Our experience with over 10 or more participants
in a single Asterisk conference was that quality
degraded quite rapidly.
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<pre wrap=""><!---->
Is this really true as there were many in this list
who had confirmed that they have used the conference
bridge for a lot more connections than what you have
Suggested as the upper limit.
Logically the conference bridge should work at the
same capacity as the number of calls Asterisk can
handle in a given configuration.
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<br>
No, that's not true at all, especially for meetme.<br>
<br>
For each member in a meetme conference, asterisk needs to decode their
audio, mix audio from every other member, and then encode that mixed
audio. The mixing operation is O(n^2). It's much simpler than the
encoding, but as the number of users goes up, it should become the
dominant operation.<br>
<br>
So, if you have N users in a meetme conference, you need to do (for
each frame, more or less):<br>
<br>
N decodes,<br>
N encodes,<br>
N*(N-1) mixes.<br>
<br>
Where N = 100, that's 9900 mixing operations. If N were 200, that
would be 39,800 mixing operations.<br>
<br>
Also, if asterisk is just bridging calls, it's generally not also
transcoding, so it's capacity to do simple things with calls is going
to be much higher than it's capacity to conference, especially with
meetme.<br>
<br>
-SteveK<br>
<br>
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<pre wrap="">
Though your solution looks impressive and probably is
the best for upto 30 simultaneous calls, I am more
interested in knowing what it takes for Asterisk to be
able to handle the 100 channels I need to run
Simultaneously.
Seshu Kanuri
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