[Asterisk-Users] Echo problem update - POSSIBLE SOLUTION

[Rich Adamson]

> After speaking with several people, and even participating in a forum of
> several other people with echo issues, I thought I'd share what we've
> done (well actually what our chief R&D engineer, Brett Bourn has
> done...)
> 
> First let me say that normal cheapy PC hardware couldn't be made to
> function with out echo.  We tried on both the single port Digium T1 card
> and the 4 port Digium T1 card.  Even on a SuperMicro Dual PIII-933 w/
> hardware scsi raid we had echo issues.  We moved everything to a Compaq
> DL380 dual PIII-833MHz (notice a slower machine) w/ hardware scsi raid.
> Same T1 cards, same compile method, and NO echo on the DL...  We did
> manage to get the echo to almost un-noticable on the Supermicro, but it
> was still there.  There is NO echo on the DL380  We are currently
> testing the Compaq 6400R for compatability and will let the list know
> how it goes.
> 
> When we install asterisk we DO modify the makefile for the zaptel
> source to look like this... (you'll add 2 lines, the Mark2 and
> Aggressive_suppressor)
> 
> KFLAGS+=-DSTANDALONE_ZAPATA
> KFLAGS+=-DECHO_CAN_MARK2
> KFLAGS+=-DAGGRESSIVE_SUPPRESSOR
> CFLAGS+=-DSTANDALONE_ZAPATA
> 
> *** info. about our current setup ***
> 
> running -- Asterisk CVS-HEAD-07/15/04-01:47:37 currently running on
> asterisk (pid = 1203)


No echo on eMachine T2240 2.2ghz Celery, 360m RAM, with either tdm04b
or x100p running any Head cvs after June 23rd (totally stock install).

Wouldn't necessarily recommend this box for any commercial production
use, but...

What's common and not so common between these _very_ diverse boxes?