On Sun 18 Aug at 02:23 Ian Smith (3:626/660{at}fidonet) wrote to Arthur Marsh:

 IS> You keep mentioning the S12s, but what about AXE?  There are 
 IS> a hell of a lot of these, up this way anyway, some of which 
 IS> have only recently been deployed, or repositioned to replace 
 IS> older ARE and even some extant crossbar gear.

Calls from those exchanges still need echo-cancellation when there is about
8 milliseconds or more of round trip delay. I don't have any idea on where
echo-cancellers are placed for such calls, unless it's in the transit
exchanges.

--- msgedsq 2.1