Subject: AMR/CNR support in Linux
From: Myung Kim <>
Date: Mon, 5 Feb 2001 16:42:35 -0800

Hi All,
Has anybody used AMR or CNR card for modem in "Linux"? (AMR=Audio Modem
Riser, CNR=Communication & Networking Riser)

AMR has been replaced with CNR by Intel. These two specifications were
created and used to sell "more" Intel Pentium CPUs. Most core chipsets from
Intel (i810, i820, i840, i815 etc.) and other Taiwanese chipset companies
(SiS, Via, ALI) design their core chipsets to support the CNR spec. so that
CNR/AMR cards can be used to do MODEM and NIC functionalities. Of course,
special device drivers are required. Similar to Linmodem drivers, but
everything is implemented in software, even more than most Linmodem drivers
because CNR cards don't even have any micro-controller or DSP. It only
includes analog part of the modem card. So, all the modem functionality is
performed by host CPU.

Most motherboards that support CNR/AMR have a small slot close to PCI slots.
Usually it is the same color as AGP slot (brown). Some motherboard vendors
make CNR cards as well.

Just in case, if you like to find more info on CNR/AMR, go to and enter CNR in search box. For motherboards, you can
go to <>  and find some motherboards with
CNR/AMR slots.

Thanks for the information in advance.