[asterisk-users] Latency in ConfBridge conferences
nick at vitell.co.uk
Thu Mar 8 14:52:34 CST 2012
I've done a basic install of 10.1.2 to have a play with the new
ConfBridge application and have noticed high latency when in a
conference. It's to the order of 900ms or so which is just too much for
a conference to work well.
I can account for about 120ms of that latency, but not the rest.
With two SIP handsets in the conference, worst case latency from handset
to handset (Handset --> Local Asterisk --> Gateway Asterisk --> PSTN -->
Gateway Asterisk --> Conference Asterisk --> Gateway Asterisk --> PSTN
--> Gateway Asterisk --> Local Asterisk --> Handset) is measured at 62ms
which leaves 780ms or so latency created by the conference bridge.
The box I'm testing ConfBridge on is a CentOS 5.7 x86_64 box with a Xeon
E31220 and loads of RAM. Whilst a two party conference is in progress,
'top' shows a load average of 0.05 and that Asterisk is using 0.5% CPU.
Assuming the ConfBridge works in Slin, 'core show translation' table
shows a 6ms (which does strike me as rather high - I get much lower
figures on much older hardware). There is no jitter buffer and the
mixing interval is 10ms. I'm pretty sure there are no bottlenecks in the
I was wondering if anybody else had experienced the same thing and/or
whether this is normal behaviour. Can I work it faster? Any ideas, or
should I just accept this?
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