Tried this config with and without the rx/tx gains
Tried with a SINGLE TDM400p
1.3GHz, 256Mb AMD
IDE at udma2
;
; Zapata telephony interface
;
; Configuration file
[trunkgroups]
echocancel=yes
echotraining=yes
echocancelwhenbridged=yes
usecallerid=yes
hidecallerid=no
callwaiting=yes
callwaitingcallerid=yes
usecallingpres=yes
threewaycalling=yes
transfer=yes
cancallforward=yes
callreturn=yes
callgroup=1
pickupgroup=1
callprogress=yes
; Produce a dial-tone when fxs pickup.
immediate=yes
[channels]
context=6651049 ; Incoming calls go to [clone] in extensions.conf
echocancel=yes ; CHANNEL 1 - TOP - IRQ 10 - Clone No Bracket
echotraining=yes ; 665-1065
echocancelwhenbridged=yes
; txgain=-6.3 the maximum function
txgain=2.0
rxgain=2.0
callprogress=no
callwaiting=yes
callwaitingcallerid=yes
busydetect=yes
signalling=fxs_ks ; Use FXS signalling for an FXO channel
group=1
channel => 1 ; PSTN attached to port 1
context=6692862 ; Incoming calls go to [plone] in extensions.conf
echocancel=yes ; CHANNEL 2 - MID - IRQ 9 - Clone
echotraining=yes ; 669-2862
echocancelwhenbridged=yes
txgain=2.0
rxgain=2.0
callprogress=no
callwaiting=yes
callwaitingcallerid=yes
busydetect=yes
signalling=fxs_ks ; Use FXS signalling for an FXO channel
group=1
channel => 2 ; PSTN attached to port 2
context=6651065 ; Incoming calls go to [dlone] in extensions.conf
echocancel=yes ; CHANNEL 3 - BOT - IRQ 5 - Digium WildCard X101P
echotraining=yes ; 665-1049
echocancelwhenbridged=yes
rxgain=2.0
txgain=2.0
callprogress=no
callwaiting=yes
callwaitingcallerid=yes
busydetect=yes
signalling=fxs_ks ; Use FXS signalling for an FXO channel
group=1
channel => 3 ; PSTN attached to port 3