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

[Soren Rathje]

Rich Adamson wrote:

[snip]

> 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)
>

[snip]

There are two types of alternative cards (not starting a discussion on who
made it first!), one called AMI-IA92 (Si3021/Si3012/MD3200) with a FCC
approval and one called AMI-IE92 (Si3021/Si3014/MD3200) with a R&TTE
approval.

The AMI-IE92 have additional components on board for setting AC real/complex
termination as well as DC termination (Japan Mode/FCC Mode/CTR21 Mode).

Both card types are compatible but the wcfxo driver does not utilise the
additional settings on the AMI-IE92 card.

Source:
Chipsets (login required)
https://www.mysilabs.com/public/documents/tpub_doc/dsheet/Wireline/Silicon_DAA/en/si3034.pdf
https://www.mysilabs.com/public/documents/tpub_doc/dsheet/Wireline/Silicon_DAA/en/si3035.pdf

Amigo Communications product sheet (www.amigocom.com)
http://61.31.72.100/amigocom/products/ami_ia92_ie92.htm

/Soren