[asterisk-users] Bad Echo between SIP calls

[Zeeshan Zakaria]

Once upon a time I used to have a lot of SIP-SIP calls issues, which not
always but sometimes included echo problems. There were no zap devices on
the server. Googling and struggling to fix it, I found out that it was
because of timing issues and ztdummy was not working properly. It had to do
something with the kernel and USB modules and something needed to be fixed
in BIOS and zaptel settings somewhere (not in zapata or zaptel confs) so
that it can have a properly working timing source. I don't remember the
details now but I remember I managed to fix it by building a different
kernel version on that server after installaing some other version of
zaptel, disabling USB modules on the motherboard, fixing something in zaptel
Makefile, disabling unused modules in /etc/sysconfig/zaptel. I don't
remember what else I did. but echo and other problems disappeared after
whatever I did. It was about 2 years ago and I remember how frustrating it
was.

Anyways, I guess once you upgraded your hardware, something changed in
zaptel settings somewhere which is now effecting the SIP-SIP calls and
resulting in echo. Do you have the backup of old setup without this card,
which you can install and check what exactly the settings were before.

Also I recommend going with Sangoma. I hear a lot of bad stories about
digium cards imcompatibility with certain motherboards and conflicts with
USB modules on the motherboard, and conflicts with IRQs. Thats why When I
went for PRI, I used Sangoma.  I've used their A101c and A101d cards, and
there have never been any issues.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20070611/5ba6473d/attachment.htm