[Asterisk-Users] volume problems on zaptel

[Tamas J]

Hello!

I have a special problem with a zaptel PRI card (E100P) with Asterisk
STABLE CVS (zaptel and libpri also from stable branch). I use iaxComm
softphone for outgoing calls (ulaw currently). Calls are going out
through PRI. After about 5-6 calls, when the 7th call arrives, the
voice volume on the called party's side is decreased, so they can't
hear much (the caller's volume kept unchanged).

zaptel.conf:
[trunkgroups]

[channels]
context=PRI1-incoming
switchtype=euroisdn
prilocaldialplan=unknown
pridialplan=unknown
overlapdial=no
signalling=pri_cpe
rxwink=300
usecallerid=yes
hidecallerid=no
callwaiting=yes
usecallingpres=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
cancallforward=yes
callreturn=yes

echocancel=yes
echocancelwhenbridged=yes
echotraining=yes
rxgain=7.5
txgain=0.5

group=1
callgroup=1
pickupgroup=1
immediate=no
adsi=no

accountcode=PRI1
channel => 1-15
channel => 17-31


What could relate to this problem? I don't have any idea why this
problem comes out and why around 7 calls.

Any hint?

Thanks in advance!
        Tamas

ps: linux-2.4.28, debian sarge, P4 3.0GHz Prescott, 512M RAM