Paul, I have not spoken with you before, so I do not know if your posting below is meant in a literal, nonfacetious manner.

...

With all of the problems with MAE-EAST.....

Any plans from anyone to create a ATM exchange point in the DC area?

For what it's worth, I do understand that there is a plan to create an ATM exchange point in the DC area, at speeds exceeding those currently available.

Given the latency we've seen over some ATM backbones,

The latency increased in network areas that are switched is generally (by all but the zealots) given to be less than that of comparable layer three data moving topologies. The latency induced by several providers claiming an ATM backbone is generally attributable to an error: they leave off one important word -- shared -- . The latency about which I assume you speak is caused by large amounts of queuing. This queuing is demanded by network oversubscription. The latency introduced by the oversubscription is consistent with any oversold network. Bear in mind, the introduced latency is not something that they directly control. However, by implementing their Internet base level transit upon a shared network, such as ATM or FR, the NSP/OSP is at the mercy of the carrier. And the carrier does so like to squeeze money out of that capital investment of an ATM network. With dedicated circuitry (SONET/SDH) the bandwidth sold is readily available, in fact fixed. With shared networks, the bandwidth is available on a 'best effort' nature, withstanding rare altruistic CIR and SCR implementations. An ATM Exchange Point implemented by a third-party should (and in one case about which I have knowledge, most assuredly WILL) disallow oversubscription within the L2 shared network. This means that the guaranteed BW really is guaranteed, and the latency induced by oversubscribing links will be 0, because the links will not be oversubscribed. (except maybe interswitch trunks [which is part of what DEC offered in Pandora's box])

I certainly hope not. I agree with Paul that MTU sizes in gigabit ethernet make it very attractive as a next step, I'd certainly be interested in seeing anything anyone has on fragmentation related delays going from a large MTU switched environment to a small MTU switched environment though.

Yes, this would be interesting.

Overall, I've been less-than-pleased with latency when I've been transited that way.

I don't understand, the MTU with which I'm most familiar on the ATM SAR Frame is 4470. How does this induce latency as a function of fragmentation? Fragmentation occurs when a PDU is larger than the available PDU space in the MTU of the transit or destination media, no? -a

Alec H. Peterson wrote:

On Wed, Nov 05, 1997 at 12:46:50PM -0800, Adam Hersh wrote:

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With all of the problems with MAE-EAST.....

Any plans from anyone to create a ATM exchange point in the DC area?

I can't think of a reason why somebody would do that.

All of the problems that mae-east is having is a clear sign that providers need to move their big peers off of the public fabric and onto private interconnects. Aside from the engineering problems, it just seems so difficult to justify having such an important part of a backbone's existance controlled by a third party. As these recent problems have illustrated, either that third party is either not capable or not willing to fix the problems. Either way, the end result is the same.

I don't think that the problems of MAE-EAST necessarily indicate problems with the exchange point concept in general. Others have indicated satisfaction with exhange points run by other parties. What the problems of MAE-EAST indicate to me is that FDDI/GigaSwitches are not the appropriate technology for MAE-EAST sized exchanges and that MFS is the wrong company to be running an exhange point. It would appear to me that there is an opportunity for a new player to get into the exchange point game. Since ATM seems to be a controversial choice to build exchange points, has anyone thought about using fast ethernet with an eventual transition to gigabit ethernet when gigabit ethernet becomes more mainstream? Jeff

Alec H. Peterson wrote:

I don't really fault MFS with these problems. Show me another exchange that is trying to pass as much traffic as MAE-east is and functioning properly.

CHI is pretty close. Also, check Pac-Bell. Smooth surf. -

+------------------------------------+--------------------------------------+ |Alec Peterson - ahp@hilander.com | Erols Internet Services, INC. | |Network Engineer | Springfield, VA. | +------------------------------------+--------------------------------------+

Actually, introducing GbE into an existing switched-FDDI environment can be a straightforward and relatively painless process. The attendees at the last NANOG were shown how this could be done in the presentation given by Celeritis Techologies and DEC. DEC has introduced a FE card with hunt group support for their GIGAswitch/Ethernet box (aka, Prominent P550). A FE hunt group between the switches and FDDI and 10/100/Gb Ethernet clients supposedly provides seamless bridging and smooth migration to GbE. You can even equip a NAP router that has an existing FDDI interface with a FE interface for loadleveling of traffic across NAP interfaces and/or for fail-over to either NAP switch. Steven At 11:28 AM 11/6/97 -0500, John wrote:

===== Alec H. Peterson previously wrote: ====

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indicated satisfaction with exhange points run by other parties. What the problems of MAE-EAST indicate to me is that FDDI/GigaSwitches are not the appropriate technology for MAE-EAST sized exchanges and that MFS is the wrong company to be running an exhange point.

Just try to bring up another point. Anyone has thought about Gigabit ethernet switches?

Prominet's Cajun switch has a 45GB backplane. Supports up to 24 full-duplex ^^^^ Gigabit ethernet ports or 120 full-duplex fastethernet ports, or a mix of both. The price is also very reasonable.

Guess that'd be too much of a change... :-) If this is not good for MAE-E, it might be good for some other new exchanges.

Jun -- Jun (John) Wu | Voice: (703)689-5325 CCIE# 2709 | Fax: (703)478-7852 Supervisor - Global IP Systems & Services | Email: jun@gip.net Global One Communications L.L.C. | URL: http://wolfox.gip.net/jun

Nathan Stratton wrote:

Yes, but it will not be airplane proof, and will be in a parking garage.

Speaking of airplane proof, has anyone bought that surplus nuclear missile silo in Texas and turned it into an exchange point? Jeff