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Date:      Sat, 4 Sep 2004 04:06:20 -0700
From:      "Ted Mittelstaedt" <tedm@toybox.placo.com>
To:        "Harti Brandt" <harti@freebsd.org>
Cc:        freebsd-atm@freebsd.org
Subject:   RE: Question on ATM w/ FreeBSD
Message-ID:  <LOBBIFDAGNMAMLGJJCKNMEDMEPAA.tedm@toybox.placo.com>
In-Reply-To: <20040903090440.Y29420@beagle.kn.op.dlr.de>

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> -----Original Message-----
> From: Harti Brandt [mailto:harti@freebsd.org]
> Sent: Friday, September 03, 2004 12:31 AM
> To: Ted Mittelstaedt
> Cc: Richard Hodges; freebsd-atm@freebsd.org
> Subject: RE: Question on ATM w/ FreeBSD
>
>
> 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,

Sigh.  I know, I just posted that to illustrate the level I'm dealing with.

When I got that response I followed up with a second query to the carrier
of whether the encap was RFC1483 Bridged or RFC1483 Routed.  Apparently that
exhausted the meager store of ATM knowledge that the technical contact had
and the
question was referred up the chain, presumably to someone more
knowledgeable.

It's week end now and I've not got a response.

The owner of the ISP wants to go with this particular carrier because
of some deals we have setup would make it very cheap, much cheaper than
anyone else.  Unfortunately it looks very much like we would be the only
ISP in Portland OR that gets an Internet feed delivered via ATM.  (at least,
the
only local one)  I think probably there's a few national carriers with POPs
here who use ATM on their backbones, no doubt.  But I have a good bit of
knowledge of our competitors here and highly doubt none
of the rest of them are doing this, most likely because they wouldn't
understand how to put it together.  Few of them are multihomed, even.

As a result of this the salespeople of the carrier we are talking to
that services our market don't know diddly squat about atm.  I won't
post who it is so as not to embarass them.

> 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).
>

My suspicion is that it's going to end up being Routed.  The reason why
is that we are already using a different group within this carrier to
provide Frame Relay to customers -ie: we buy Frame circuits from their
network to supply bandwidth to customers.  Basically it's ATM vc's from us
to their ATM switch which interworks it to a Frame circuit that the
end user sees on the usual T1.  That is of course a completely separate
DS3 than what we are looking at buying.  But the circuits provisioned off
that are Routed not bridged, and all5snap, and vbr.

It would also almost certainly be a single VC on the DS3.

DSL egress in this market, by contrast, is all Bridged, both with Verizon
and Qwest.  (we have both those ilecs here, ugh)  They both use vbr and
aal5mux.

I have another question for you guys,- if I am using routed/vbr is there any
benefit to using a forerunner he155 and the fatm() driver as opposed to
a Fore LE155 with the idt() driver?  Also, what exactly is the difference
between a Fore LE155 and a Fore PCA-200 (which uses the hfa() driver I
understand)?

You are right in there being no cheap IDT77252 cards out there.  I don't
have
$2-3K on this project to throw into atm pci cards. :-(

Has anyone worked with the Ascend/Lucent/Avaya PSAX gear, like the PSAX 100?
Is that an ATM switch that could run a VC from one interface to another?
The
documentation on Avaya's site is very unclear plus the PSAX 100 has been
long
discontinued.  But because of that they appear to be rediculously cheap on
the secondary market.


Ted

> 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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