Hello!
While voice from PSTN = original digium X100P to Asterisk (mailbox, SIP) is fine, the other way (SIP, wav, sln, mp3 to PTSN) is heavily choppy (frequent interruptions with loss of data) and, in rare cases, noisy. In test calls, people asked me to repeat whole sentences, or said: “I understood nothing after the word: …”.I cannot use Asterisk for telephony as long as people don’t understand what I’m saying.
Asterisk 1.2.13 (debian package)
kernel 2.6.8
Debian 1:3.3.5-13
The problem exists exactly in the same fashion since my first installation of asterisk years ago (installation from source on another PC). Therefore, it does not seem to depend on a certain version of asterisk or the kernel. I also tried several softphones and SIP hardware. It must be something with asterisk.
I appreciate all hints. Please help.
sip.conf
[mobfon]
type=friend ; Friends place calls and receive calls
context=intern ; Context for incoming calls from this user
username=mobfon
fromuser=mobfon
secret=***********
language=de
host=dynamic
dtmfmode=rfc2833
disallow=all
allow=alaw ; dtmfmode=inband only works with ulaw or alaw!
canreinvite=yes
zapata.conf
[trunkgroups]
[channels]
context=incoming
signalling=fxs_ks
rxwink=300
usecallerid=yes
hidecallerid=no
callwaiting=yes
usecallingpres=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
canpark=yes
cancallforward=yes
callreturn=yes
echocancel=yes
echocancelwhenbridged=yes
rxgain=0.0
txgain=0.0
group=1
callgroup=1
pickupgroup=1
immediate=yes
jitterbuffers=16
channel => 1
dmesg
Memory: 120852k/129984k available (2019k kernel code, 8584k reserved, 858k data, 168k init, 0k highmem)
CPU: Intel Pentium III (Coppermine) stepping 06
..... CPU clock speed is 738.0160 MHz.
..... host bus clock speed is 134.0211 MHz.