[asterisk-dev] Zaptel Echo Cancellation

[John Lange]

On Thu, 2006-08-03 at 14:36 +0100, Steve Davies wrote:

> Note that 16ms is plenty for most echo sources that occur in a real system.

Would you mind expanding on that? 16ms seems like the bare minimum?

Is there not an inherient delay of several ms due to CPU and encoding
overhead etc or is this not a factor in the calculations? I'm just
wondering what kinds of delays play into this or is the only thing that
matters the delay on the PSTN before the signal hits the card?

On a side note; does anyone know of a way to implement hardware echo
cancellation on a single-span system? Are there external hardware echo
cancelers that can be added into the equation?

Are either digium or sangoma working on hardware echo cancel for single
span cards?

Regards,

John