Audio pops in live audio streaming system.

>In a live audio streaming system, audio pops are caused by network
>packet delay. How to smooth the sharp decay, and what stuff should be
>filled in the empty buffer?
>

Are temporay mutes acceptable for your application?  Sometimes you can
size them so that they are so small a human may not easily detect it.

For example keep a 100ms buffer between input and output and put a timer
on your input.  Once you determine the input pack is late (you define
this) you can start appling a exponential mute (RC) to your outgoing
samples.

Since you have a 100ms in the pipe, you could adjust your rate so that it
is attentuated to -80dB (assuming a full-scale input) at around 50ms. 
This time amount is key because anything less than ~30ms rate will be
preceived as a pop.

If the input packet comes back right after your mute is complete: you fill
the buffer back up and start your unmute process after the buffer is full
again.  If you're lucky your packet delay is less than 50ms and the
amplitude will drop temporarily and go back up to unity and hardly anyone
will be able to distinguish that.

Worst case is a several-hundred-ms mute which is a little annoying but far
less discernable than a pop [my opinion].

Just an idea...
- Jeff