[Asterisk-Users] Echo - UK Impedance problem with X100P?

[James Botham]

I am not willing to spend money on a system where even the most basic things
are incompatible with everybody but the US, this is just stupid I am using
the X100P in a small office so that we can have a small PBX, seems daft
having to upgrade my hardware just because of another US oversight. I am
using a Gigabyte Titan 4 Pro motherboard and also tried it on another PC
with an Intel motherboard and it had the same affect it could be Zapata.conf
but pin pointing this is getting stupid I might invest in a commercial PBX
as this is wasting so much of my time, its a good idea but saying the
product is in its infancy is an overstatement.

-----Original Message-----
From: Rich Adamson [mailto:radamson at routers.com]
Sent: 12 November 2004 13:27
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [Asterisk-Users] Echo - UK Impedance problem with X100P?


> I have an X100p interface (clone).  The system works fine but I get
> echo to a level where the system is all but unusable for IP  PSTN.  I
> seem to remember reading somewhere that the UK line impedance is 
> different from the default compile and needs changing.   I have
> Wikied etc, but found nothing yet.

The x100p (and presumably the clones) have an integrated circuit on the
board that was manufactured for use in the US with 600 ohm pstn lines.
The chip cannot be changed to any other impedance. However, there can
be many different sources for the echo and impedance matching is only
one of them. Others include:
 - incorrect * zapata.conf parameters
 - poorly engineered motherboards (eg, poor PCI bus, interrupt latency)

For zapata.conf, try something like:
echocancel=yes
echotraining=800

For poorly designed motherboards, there is no consolidated list of
which ones are good/bad so you're left with trying another one on your
own to see if it impacts the echo.

The TDM04B digium card (as an example) does not use that same pstn
chip, but rather another one from the same chip manufacturer. That
chip does have support for something like 18 different "country"
telco standards.



_______________________________________________
Asterisk-Users mailing list
Asterisk-Users at lists.digium.com
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users


This email and any files transmitted with it are confidential and intended
solely for the use of the individual or entity to whom they are addressed.
If you have received this email in error please notify the system manager.
Please note that any views or opinions presented in this email are solely
those of the author and do not necessarily represent those of the company.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20041112/75622cca/attachment.htm