[Asterisk-Users] Echo on PRI/BRI?

[Rich Adamson]

> Does echo only occur on analogue PSTN lines, or can it also occur on PRI and
> BRI lines? 

Yes, it can occur on any type of line.

> If so, for the same reasons? This is a part of our consideration
> to transition to BRI.

It is the result of 4-wire to 2-wire conversion "somewhere" between
your end and the called end. For example, if you originate a call on
a PRI/BRI, and you call a telephone number in an analog central office
a hybrid conversion will occur somewhere near that terminating CO. 
That conversion _can_ be a source of echo.

In general terms, there are significantly fewer echo issues with PRI's
and BRI's then there is with any analog pstn connection.