Date: Tue, 20 Apr 1999 11:46:14 -0700 (PDT) From: Doug White <dwhite@resnet.uoregon.edu> To: Mark Tinguely <tinguely@plains.NoDak.edu> Cc: a.bob@xtra.co.nz, questions@FreeBSD.ORG Subject: Re: ADSL modem ss3020 Message-ID: <Pine.BSF.4.03.9904201142520.1514-100000@resnet.uoregon.edu> In-Reply-To: <199904142201.RAA06933@plains.NoDak.edu>
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On Wed, 14 Apr 1999, Mark Tinguely wrote: > > > > Would it be sufficintly similar to the ATM cards? > > > > It's not an ATM card. > > It is time to do a "public service announcement" that when DSL cards > talk about ATM, they mean they run ATM cells on top of the DSL frames > (whereas traditional ATM cards run ATM cells in SONET frames). > > I read this person's question as asking how close the ATM SAR on the DSL > card matches the ATM SAR on the traditional SONET card and how difficult > would it be to port. Maybe I assumed too much about the question. > > >From what I read in the Efficient web page, I would guess they are not > simular, but I suggested that he ask the question in freebsd-atm mailing list, > because someone in that group may have more information on that DSL card to > give a definitive answer. > > Unfortunately even if the underlining media was the only difference > and it was a few lines different, we may have to make changes to the > network stack. HARP supports Classical IP over ATM. The ISP/telco > could be using PPP over ATM, or Bridged Ethernet over ATM. Most DSL implementations use bridged Ethernet, so it has to come out in some sort of Ether frame somewhere. It would be easier to just have a Ethernet NIC chip be the interface to the machine and do the ATM <-> Ether conversion internally. Of course that's not to say that they would actually build the board that way, but it would save you the driver development if you looked like a DECchip Ether card. I assume the internal cards don't need to have a router mode like the external CPE's commonly implement. > The external DSL <> ethernet bridge/router are the best way to go for > cost/effort, but in 6 months to a year we are going to be seeing people > screaming for drivers for the board their ISP/telcom gave them. Unless > things really change in regard to getting documentation, the standard reply > for them will be buy the external bridge/router or they are SOL. I hope > things will change and DSL drivers are as common as ethernet card drivers > are today. We need specifications. Doug White Internet: dwhite@resnet.uoregon.edu | FreeBSD: The Power to Serve http://gladstone.uoregon.edu/~dwhite | www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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