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Date: Fri, 3 Dec 2004 16:56:06 -0800
From: Bruce M Simpson <bms@spc.org>
To: Jose M Rodriguez <josemi@freebsd.jazztel.es>
Message-ID: <20041204005606.GF745@empiric.icir.org>
References: <200412021702.53996.freebsd@redesjm.local>
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cc: hackers@freebsd.org
cc: Andre Oppermann <andre@freebsd.org>
cc: freebsd-usb@freebsd.org
cc: net@freebsd.org
Subject: Re: about a usb adsl modem driver
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On Fri, Dec 03, 2004 at 09:25:56PM +0100, Jose M Rodriguez wrote:
> But noted strong differences between atm boards and adsl modems.
> 
> - atm boards are hardware assisted.  usb adsl modems are bare assisted.
> - atm boards support better signaling, multiple channels, ... usb adsl 
> modems just one PVC with uni signaling.

Not really. See below.

> So I realize that try to get a NATM/NETGRAPH hardware driver may be too 
> work for little gain.

Actually writing a NATM driver is far easier than writing a HARP driver.
And Harti's newer drivers for ATM cards are, in fact, NATM drivers. You
only need to implement Netgraph hooks. You don't need to worry about
implementing Netgraph protocol nodes, generally.

You might want to contact Benno Rice, he was working on a software AAL5
kernel module to augment netnatm, which would help if you're targeting
the lower end ADSL hardware.

Regards,
BMS