Network Testbed Emulab.net

gseidman writes: "Have you ever needed to simulate a network? Tired of old ns? Do you just hate dealing with hardware in general? Take a peek at Utah's Emulab.Net. They have over 300 PCs, some StrongARM devices, roughly 5 miles of cabling, a huge and expensive switch, and great software for setting up a virtual LAN. They also have a gallery showing the machine room in various stages of completion (did I mention five miles of cabling?)."

Comments

This is very cool.

[perdida]

This is applied research, the type that may have direct and positive effects on improving security and efficiency in the immediate future.

Unlike dark matter research, Mars colonization, and subatomic research, this stuff is the kind of thing that should attract wide funding from business. Immediate payoffs are likely.

Basic research is fine, but I wish that the money poured into it would go towards immediate business applications. More available cash would make those venture capitalists a lot nicer and less demanding of unrealistic profits in an unrealistic period of time.

Re:This is very cool.

[fnordboy]

Basic research is fine, but I wish that the money poured into it would go towards immediate business applications.

Now that's just silly. Basic research is incredibly important, and it is vital to the economic health of the country (and the world, for that matter) that money is spent on it. Where did the transistors that your nice new Intel chip is made up of come from? Basic research. How about lots of medical technology like MRI machines and x-rays? Basic research. And there are lots of indirect benefits to basic research as well. How about those snazzy digital cameras? The need for high-quality CCDs for astronomy (*cough* hubble *cough*) and for other research applications pushes that. Do you like the world wide web? Thank a bunch of physicists who put it together so they could share their data.

The point of basic research isn't the small, immediate payoff - it's the hope that somewhere along the line, some scientist is going to come up with something that will revolutionize the world - just like the transistor! So I respectfully disagree with you - while it's important for companies to be concerned with their quarterly earnings reports, in the long term, basic research is most certainly worth the investment.

Emulating the /. effect

[Brento]

It's already starting to slow down. Now would be a good chance to start dedicating some of those machines as backup web servers, eh?

This could be a nightmare

[Quasar1999]

5 miles of cables? I hope they labled them... :)

Simulation is never perfect

[euroderf]

This is the difference between book learning and experience. Sure, you can 'test' a network under idealised simulated conditions, as one might 'test' a plane in a wind tunnel, but till the network is reality, and the secretary spills a cup of coffee on the router or the chief engineer urinates drunkenly on the packet switcher, you can't tell how your network will perform.

What is it with the modern generation who think that simulations will improve their likely performance? It is all idiocy, when I was young we did things with a spanner and looked at das blinkenlights under real world conditions. This is so much nonsense, really, the sort of thing I'd expect to come out of our modern CS courses.

Computing is just an offshoot of down-and-dirty engineering, and none of us should forget it. The day we forget the feel of the netowrk cards in our hands, the smell of the overheating cat5, is the day we lose control over the netowkrks of America, the day that our economy starts going backwards.

5 Miles of sloppy cabling...

[GLX]

I don't know what brainchild designed the layout of those switches, but the fact that they went for the RJ-48 blades versus the Telco (RJ21X) blades in those switches shows sloppy planning. What if one of the blades in the middle goes out? They have to unplug 48 Cat-5 cables versus unscrewing 4 telco harmonicas and leaving the 48 ports untouched on a patch panel

If you're going to put forth that kind of effort and money, why not do it right the first time?

Agreed

[clark625]

I totally agree with you. Simulation doesn't prove that things will be all peachy cream later on in the "real world".

Then again, if a 1/100th scale model does a nose dive in the wind tunnel when they throw a little turbulence at it, you can bet the ranch that plane will be redesigned. Testing and modeling only show the existence or non-existence of very particular problems. We just usually hope that we can "test" out as many likely problems as possible.

Re:5 miles, big deal.

[mac.newbold]

I was one of the few 'lucky' people who had to run it, and no, we didn't run it thorough a 2ft high crawl space. It is even worse than that.

In case you couldn't tell from the pics, this is all in self contained racks. The large majority of the wiring is in 9 standard-sized racks, or about 7ft tall * 3ft deep * 2 ft wide * 9 racks = 378 cubic feet for about 5 miles (25,000 ft) of cable plus all the PCs and switches.
As a generous estimate, that leaves 100 cubic feet for cables and ventilation. That says the every cubic foot of open space is filled with an average of 250 linear feet.

Needless to say, it was not fun.

Mac

Only 5 miles?

[yzquxnet]

The post submitter makes 5 miles of cable seem like a lot. Well, it isn't. Even a small office complex can burn through 50,000 ft a cabling in short work. Running two data cables effectivly doubles your cable requirements. Depending on the situation the installer may even lay a third cable for voice. (What standard was that?) Anayways, 5 miles of cable is not a lot.

Just a bit surprised ?

[pruneau]

Those guys just bought those 4 huge 6509C Cisco switches for big bucks.

I assume that One is acting as the main router, and the other are using it. I assume also that the switches are interconnected with 2x1Gb/s fibers, probably full-duplex and load/sharing above the two links.

What surprises me is that those switch fabric supports up to 256Gb/s bandwidth, but they are just connected with 2Gb/s links : talk about some bottlnecks here...

But maybe I did not read enough documents ?

Any comments from the builders of that lab ?

Re:Notice the hardware config?!?

[A Commentor]

Wrong... that was the 75GXPs. See the original article.

I double checked a few posts, and they mentioned that the 60GXP was much more reliable.