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

[Rich Adamson]

No offense intended, but the x100p card was never marketed in the UK (or
other countries) by digium, etc. Those that found a way to purchase the
card obviously didn't do the research necessary to understand what they
were getting into and probably didn't have any sort of understanding of
what their country telco standards actually were from a system engineering
perspective. Those that elected the clones obviously have even less
knowledge/experience.

As far as the motherboard issue, its not just the digium products that
have an issue. If you know of someone that is heavy into using audio
applications (eg, song writers, midi stuff), they have known about the
pci / interrupt latency issues on certain motherboards for a loooong 
time. Wouldn't doubt those folks maintain a list of what's reasonable 
verses unacceptable.

------------------------
> 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.
> 
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