Date: Thu, 2 Sep 2004 23:26:05 -0700 From: "Ted Mittelstaedt" <tedm@toybox.placo.com> To: "Harti Brandt" <harti@freebsd.org>, "Richard Hodges" <rh@matriplex.com> Cc: freebsd-atm@freebsd.org Subject: RE: Question on ATM w/ FreeBSD Message-ID: <LOBBIFDAGNMAMLGJJCKNMEDLEPAA.tedm@toybox.placo.com> In-Reply-To: <20040902154912.U26182@beagle.kn.op.dlr.de>
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Thanks, There is only going to be one VC. I asked about the delivery encap and they said "vbr" Ted > -----Original Message----- > From: Harti Brandt [mailto:harti@freebsd.org] > Sent: Thursday, September 02, 2004 6:59 AM > To: Richard Hodges > Cc: Ted Mittelstaedt; freebsd-atm@freebsd.org > Subject: Re: Question on ATM w/ FreeBSD > > > On Mon, 30 Aug 2004, Richard Hodges wrote: > > RH>On Mon, 30 Aug 2004, Ted Mittelstaedt wrote: > RH> > RH>> Hi All, > RH>> > RH>> Can I plug in an ATM DS3 into something like a Cisco > Lightstream LS1010 > RH>> with a DS3 card, then plug a PC running FreeBSD and Quagga, with a > RH>> Marconi Forerunner HE155 using the fatm() driver, into a OC3 card on > RH>> the LS1010, then define a VC, switch it through the switch, > RH>> and run data over that? > RH> > RH>I cannot answer for netgraph-atm (maybe Harti could help there), but I > RH>have some knowlege about the Fore/IDT LE155 card and HARP/ATM in the > RH>later versions of 4.x > RH> > RH>HARP supports RFC1483 routed packet encapsulation, and if your > other end > RH>supports this, then you should be fine. Many or most > ATM/Ether switches > RH>prefer 1483 bridged encapsulation, so this is an important > thing to check. > RH>LANE (LAN emulation) uses bridged, CLIP (classical IP) uses routed > RH>encapsulation, by the way. > > With NgATM you can also use HE155 cards (nice if you need CBR shaped > VCCs), IDT 77252 based cards (ProSum has these, they support also VBR) in > addition to the HARP supported cards. As for the protocols NgATM > does only > CLIP over PVCs at the moment, but you can use the card capabilities for > shaping with this if you need to (see natmip(4) and atmconfig(8)). > > RH>The LS1010 or any decent ATM switch should be fine to link your DS3 to > RH>OC3. For the price, I would go for a Fore ASX-200BX or an ASX-200WG > RH>converted to a -BX (by upgrading the CPU board). The -WG is > usually very > RH>cheap on ebay. > RH> > RH>> We are looking into bringing in another feed this time via ATM DS3, > RH>> and I don't think that a DS3 ATM card exists for the PC that has a > RH>> FreeBSD (or Linux) driver. > RH> > RH>I think Imagestream sells one, but I would rather spend a > couple hundred > RH>on an ATM switch than a thousand or more on a PCI card. > RH> > RH>> However I see a number of PCI ATM lan adapters for PC's. > RH> > RH>The Fore/IDT LE155 cards are cheap and functional. > > Fore PCA200E and HE155 are also for 10$ on ebay. > > RH>> It seems that an ATM switch, of which there are plenty > RH>> available, would be the way to get from one to the other. However I > RH>> have not dealt yet with ATM switches, is there anything > inherently different > RH>> about ATM on a lan adapter like the HE155, and ATM on a DS3? > RH> > RH>Not really. Obviously the cell rate is different. This _might_ be an > RH>issue if your host with the OC3 bursts packets to the point > that your DS3 > RH>bandwidth is exhausted and packets are discarded. By the way, > if you have > RH>an option for EPD (early packet discard), this can help reduce > the damage > RH>in this case. One ugly way to fix this would be to hack the IDT driver > RH>to force a lower cell rate. On the other hand, if your traffic is TCP, > RH>flow control might not be an issue. > > If the traffic goes over a single PVC you can configure this PVC to shape > the traffic to a DS3 bandwidth. But that just moves the dropping point > from the ATM switch to the host. As Richard said, TCP should take care > itself. > > harti > > RH>I think the key is making sure that the other end can handle RFC1483 > RH>routed encapsulation. > RH> > RH>You should have no trouble finding the LE155 card, the switch, > and the OC3 > RH>and DS3 modules on ebay, but feel free to contact me for parts if you > RH>wish. > RH> > RH>All the best, > RH> > RH>-Richard > RH> > RH>_______________________________________________ > RH>freebsd-atm@freebsd.org mailing list > RH>http://lists.freebsd.org/mailman/listinfo/freebsd-atm > RH>To unsubscribe, send any mail to "freebsd-atm-unsubscribe@freebsd.org" > RH> > RH> > RH> >
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