[Freeswitch-users] Jitter Buffer specifics

[Danny G]

According to the FS wiki the 3 jitterbuffer parameters are:

initial buffer, max buffer, max drift.

     - Length is initial size of jitter buffer

What does this do in terms of affecting how packets are handled?  
What happens during a call that affects length?  
What happens when it is exceeded?  

     - max length is upper bound for how big jitter buffer can grow

What happens when  the max length is reached?  
What is difference between max length and length 
and how do they interact as params to act on the system?

    - Max drift controls how much delay

What is delay measured by in terms of time it takes for a packet to arrive? 
How does that then interact with the other two params to act?

Thanks for the help.