Date: Fri, 3 Sep 2004 09:31:00 +0200 (CEST) From: Harti Brandt <harti@freebsd.org> To: Ted Mittelstaedt <tedm@toybox.placo.com> Cc: freebsd-atm@freebsd.org Subject: RE: Question on ATM w/ FreeBSD Message-ID: <20040903090440.Y29420@beagle.kn.op.dlr.de> In-Reply-To: <LOBBIFDAGNMAMLGJJCKNMEDLEPAA.tedm@toybox.placo.com> References: <LOBBIFDAGNMAMLGJJCKNMEDLEPAA.tedm@toybox.placo.com>
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On Thu, 2 Sep 2004, Ted Mittelstaedt wrote: TM>Thanks, TM> TM> There is only going to be one VC. I asked about the delivery TM>encap and they said "vbr" Hmm. VBR is not an encapsulation, its Variable Bit Rate. In this case you should get either and IDT77252 or IDT77211 based card (I don't know whether there are cheap 77252 cards, but you find Fore LE155 with a 77211 for a handful of $ on ebay). Richard probably knows better to what extend the LE155 supports VBR. atm_load="idt" atm_netif_idt0="idt 1" atm_sigmgr_idt0="pvc" ifconfig_idt0="a.b.c.d" There is currently no magic in the rc.d scripts to add PVCs as far as I can see (although defaults/rc.conf suggests so). You need something like: atm add pvc idt0 0 <vci> aal5 llc/snap ip idt0 <remote-ip> vbr <peak> <sust> If you have bridged LLC - I don't know whether HARP can do this. With NgATM you can use the ng_atmllc node to strip of the LLC header and put the resulting PDU on an ethernet interface. We did this a couple of weeks ago with an FreeBSD user in Latvia. I can dig out the e-mail with the exact configuration. But in that case you cannot easily use the HARP idt driver. I sent my NgATM driver for the 77211 to someone a couple of months ago who wanted to work on it, but I don't know what happend to this. It would also be possible to feed the traffic from HARP into NgATM with a 50 line program - 50MBit/sec is easily doable. You could also ask ProSum for a price of their 77252 cards (www.prosum.fr). At the end, if the whole link is yours you can simply use any card and not shape altoghether (it doesn't make any difference whether you have CBR or VBR if you have the entire link. You need to ask your provider for the traffic parameters). harti TM> TM>Ted TM> TM>> -----Original Message----- TM>> From: Harti Brandt [mailto:harti@freebsd.org] TM>> Sent: Thursday, September 02, 2004 6:59 AM TM>> To: Richard Hodges TM>> Cc: Ted Mittelstaedt; freebsd-atm@freebsd.org TM>> Subject: Re: Question on ATM w/ FreeBSD TM>> TM>> TM>> On Mon, 30 Aug 2004, Richard Hodges wrote: TM>> TM>> RH>On Mon, 30 Aug 2004, Ted Mittelstaedt wrote: TM>> RH> TM>> RH>> Hi All, TM>> RH>> TM>> RH>> Can I plug in an ATM DS3 into something like a Cisco TM>> Lightstream LS1010 TM>> RH>> with a DS3 card, then plug a PC running FreeBSD and Quagga, with a TM>> RH>> Marconi Forerunner HE155 using the fatm() driver, into a OC3 card on TM>> RH>> the LS1010, then define a VC, switch it through the switch, TM>> RH>> and run data over that? TM>> RH> TM>> RH>I cannot answer for netgraph-atm (maybe Harti could help there), but I TM>> RH>have some knowlege about the Fore/IDT LE155 card and HARP/ATM in the TM>> RH>later versions of 4.x TM>> RH> TM>> RH>HARP supports RFC1483 routed packet encapsulation, and if your TM>> other end TM>> RH>supports this, then you should be fine. Many or most TM>> ATM/Ether switches TM>> RH>prefer 1483 bridged encapsulation, so this is an important TM>> thing to check. TM>> RH>LANE (LAN emulation) uses bridged, CLIP (classical IP) uses routed TM>> RH>encapsulation, by the way. TM>> TM>> With NgATM you can also use HE155 cards (nice if you need CBR shaped TM>> VCCs), IDT 77252 based cards (ProSum has these, they support also VBR) in TM>> addition to the HARP supported cards. As for the protocols NgATM TM>> does only TM>> CLIP over PVCs at the moment, but you can use the card capabilities for TM>> shaping with this if you need to (see natmip(4) and atmconfig(8)). TM>> TM>> RH>The LS1010 or any decent ATM switch should be fine to link your DS3 to TM>> RH>OC3. For the price, I would go for a Fore ASX-200BX or an ASX-200WG TM>> RH>converted to a -BX (by upgrading the CPU board). The -WG is TM>> usually very TM>> RH>cheap on ebay. TM>> RH> TM>> RH>> We are looking into bringing in another feed this time via ATM DS3, TM>> RH>> and I don't think that a DS3 ATM card exists for the PC that has a TM>> RH>> FreeBSD (or Linux) driver. TM>> RH> TM>> RH>I think Imagestream sells one, but I would rather spend a TM>> couple hundred TM>> RH>on an ATM switch than a thousand or more on a PCI card. TM>> RH> TM>> RH>> However I see a number of PCI ATM lan adapters for PC's. TM>> RH> TM>> RH>The Fore/IDT LE155 cards are cheap and functional. TM>> TM>> Fore PCA200E and HE155 are also for 10$ on ebay. TM>> TM>> RH>> It seems that an ATM switch, of which there are plenty TM>> RH>> available, would be the way to get from one to the other. However I TM>> RH>> have not dealt yet with ATM switches, is there anything TM>> inherently different TM>> RH>> about ATM on a lan adapter like the HE155, and ATM on a DS3? TM>> RH> TM>> RH>Not really. Obviously the cell rate is different. This _might_ be an TM>> RH>issue if your host with the OC3 bursts packets to the point TM>> that your DS3 TM>> RH>bandwidth is exhausted and packets are discarded. By the way, TM>> if you have TM>> RH>an option for EPD (early packet discard), this can help reduce TM>> the damage TM>> RH>in this case. One ugly way to fix this would be to hack the IDT driver TM>> RH>to force a lower cell rate. On the other hand, if your traffic is TCP, TM>> RH>flow control might not be an issue. TM>> TM>> If the traffic goes over a single PVC you can configure this PVC to shape TM>> the traffic to a DS3 bandwidth. But that just moves the dropping point TM>> from the ATM switch to the host. As Richard said, TCP should take care TM>> itself. TM>> TM>> harti TM>> TM>> RH>I think the key is making sure that the other end can handle RFC1483 TM>> RH>routed encapsulation. TM>> RH> TM>> RH>You should have no trouble finding the LE155 card, the switch, TM>> and the OC3 TM>> RH>and DS3 modules on ebay, but feel free to contact me for parts if you TM>> RH>wish. TM>> RH> TM>> RH>All the best, TM>> RH> TM>> RH>-Richard TM>> RH> TM>> RH>_______________________________________________ TM>> RH>freebsd-atm@freebsd.org mailing list TM>> RH>http://lists.freebsd.org/mailman/listinfo/freebsd-atm TM>> RH>To unsubscribe, send any mail to "freebsd-atm-unsubscribe@freebsd.org" TM>> RH> TM>> RH> TM>> RH> TM>> TM> TM> TM>
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