[asterisk-users] Source-IP on Asterisk DRBD/-HA-Cluster wrong

[Alex Balashov]

Thorolf Godawa wrote:

> Unfortunately I think (and this is also my experience), a virtualized
> Asterisk server will not work on higher load and might loose
> UDP-VoIP-pakets what will result in a bad voice quality!

Much has been said of this topic.  In general, you are correct;  the 
effects of mostly userspace scheduling on timing tolerance and system 
responsiveness in a classical virtualisation scenario can lead to more 
jitter and stochastic variance in packet forwarding, even if not 
necessarily packet loss per se.

However, virtualisation technology is evolving in directions that make 
it increasingly "natively" bound to the underlying hardware - i.e. 
paravirtualisation.  Running Asterisk in a VZ-style VPS is very 
different than running it in a Xen VM slice, for example, because in 
the former case it is basically a glorified chroot jail;  there is a 
shared underlying kernel and simulated process space isolation.  In 
the latter, an actual virtual machine is run, although it is still 
native-bound to some degree in that it is not a pure 
userspace-scheduled process.

So, the answer is somewhat qualified;  it depends on what is meant by 
"generalisation."

-- Alex

-- 
Alex Balashov - Principal
Evariste Systems
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