[Asterisk-Dev] Re: [Iaxclient-devel] jitterbuffer

[Steve Underwood]

Jesse Kaijen wrote:

> Hi,
>
> Basic definition for reference: "Jitter is a measure of the 
> variability over time of the latency across a network. A very low 
> amount of jitter is important for real-time applications using voice 
> and video."
>
> Jitter calculation is the standard deviation of the historical delay 
> of packets during the conversation.
> Because calculating std. dev. is very cpu intensive, especially when 
> you have to predict which curve you're having (Gauss, Poisson, etc), 
> the jitter may be approximated by taking the IQR (inter quartile range).

IP network jitter looks nothing like those. The nearest common 
distribution would probably be Rayleigh. What you need to assess is the 
nature of the long tail.

> I am sending this to the asterisk-dev as well because the underlying 
> implementation is currently also being worked into Asterisk (-head). 
> Hopefully my notes will help all implementations evolve.

Regards,
Steve