What's So Big About CRS-3?

Cisco did have some tricks up its sleeve for its new core router, but as you'd expect, other vendors are quick to pounce on it

Craig Matsumoto, Editor-in-Chief, Light Reading

March 9, 2010

4 Min Read
What's So Big About CRS-3?

Commentators seem underwhelmed that the CRS-3 core router, announced by Cisco Systems Inc. (Nasdaq: CSCO) today, didn't really change the Internet. (See Cisco Boosts the Core With CRS-3.)

The CRS-3 is more Cisco's anticipated upgrade of the CRS-1 core router to 100-Gbit/s interfaces, and as such, it's making an easy target for router rivals who've already made 100-Gbit/s announcements. Instead of a rush of adrenaline, Cisco produced "maybe a little bit of caffeine, not even a strong cup of coffee," says Houman Modarres, director of IP product marketing at Alcatel-Lucent (NYSE: ALU).

Still, the CRS-3 starts what Cisco says will be a flurry of 2010 announcements related to service providers. It's clear that Cisco, in a sense, does intend to build a re-imagined Internet out of intertwined Cisco pieces.

GPS for data centers
The most crucial aspect of the CRS-3 probably isn't the capacity -- everyone knew Cisco was going to upgrade someday -- but the way it interacts with the data center. Cisco's announcement today showed one such feature called the Network Positioning System (NPS).

NPS uses routing protocols to identify the shortest path to virtualized resources, such as servers or video storage. NPS then connects the user to those resources via an MPLS virtual private network (VPN, duh). If there's already a VPN in place, NPS would create a spoke for the VPN to reach the data center.

This ties into the whole idea of cloud computing. (As former Light Reading editor Scott Raynovich noted on his Rayno Report blog: "Cisco’s done it… Somehow, they’ve managed to tie Core routing to Cloud Computing! Buzzword bonus!")

Specifically, if the resources at one data center get strained, NPS can locate additional resources at another site that's somewhere in the cloud. Since it's all virtualized, the end user shouldn't notice anything has happened.

This brings the core router into a new role, actively identifying resources on the network and creating connections that the end user didn't necessarily ask for.

"We're just seeing a lot of new traffic patterns," says Cisco director of marketing Mike Capuano. "It used to be from the service provider to the business or consumer and back. Now, it's between data centers."

The choice of involving the CRS-3 in NPS is going to lead to some architectural debates, namely: Would it be better to put this functionality at the edge?

"You don't want your core router optimizing any of that stuff. It doesn't have services capabilities anyway," says AlcaLu's Modarres. "The edge is where the services are originated and are delivered."

"I would figure that you'd rather have your data center or your application decide where the resources are needed," says Luc Ceuppens, a Juniper Networks Inc. (NYSE: JNPR) senior director of marketing.

But Cisco argues that the core is the right place for this. "That is where the network has visibility to a broader set of resources," says Capuano.

Cisco is trying to standardize the NPS's methods of determining proximity, in the IETF Application Layer Traffic Optimization Working Group (ALTO WG).

Running the numbers
It's still fun to talk about router specifications, though, so let's fill in some of those details.

As noted, the CRS-3 is a CRS-1 outfitted for 100-Gbit/s interfaces. The CRS-1 could only support 40-Gbit/s ports, which had recently become a crucial difference between Cisco and its biggest router competitors: Alcatel-Lucent, Juniper, and Huawei Technologies Co. Ltd. have all announced plans for 100-Gbit/s ports.

Rivals aren't passing the opportunity to point that out. "We welcome Cisco to the 100-Gbit/s club," says Juniper's Ceuppens.

The 40-Gbit/s limit was a function of the switching fabric available on the CRS-1, Cisco now says. The upgrade to the CRS-3 involves simply swapping out the switching cards; the backplane was built with this upgrade in mind, Capuano says.

With the upgrade, Cisco can run 140 Gbit/s per slot, with switching capacity of 4.48 Tbit/s per chassis. (The latter figure is doubled to count ingoing and outgoing traffic at the same time, as the industry tends to do.) It takes 72 chassis to fill out the 322 Tbit/s that Cisco talked about in today's release; the number is similar in spirit to the 92 Tbit/s Cisco so proudly trotted out with the CRS-1. (See Cisco Unveils the HFR.)

The CRS-3 is slated to be generally available in the September quarter, with linecard options that will include one 100-Gbit/s port, 14 10-Gbit/s ports, or 20 10-Gbit/s ports.

The new cards have been engineered for low power, so that even while it's handling more traffic, the CRS-3 won't eat up more power than the CRS-1, Cisco claims. "We've more than tripled the capacity in the same power footprint," Capuano says.

Specifically, Cisco says the CRS-3 consumes as little as 2.75 Watts per Gbit/s of traffic.

Other companies can't match Cisco's 322-Tbit/s claim, but when it comes to more practical router metrics that would lead to immediate sales, they're all on a par. Juniper expects to leapfrog Cisco's 140 Gbit/s per slot by moving to 250 Gbit/s in the first half of 2011, and Alcatel-Lucent has laid out plans to pack ten 100-Gbit/s interfaces in one-third of a rack later this year. (See Juniper Upgrades the Core and AlcaLu Readies 100GigE Cards .)

— Craig Matsumoto, West Coast Editor, Light Reading

About the Author(s)

Craig Matsumoto

Editor-in-Chief, Light Reading

Yes, THAT Craig Matsumoto – who used to be at Light Reading from 2002 until 2013 and then went away and did other stuff and now HE'S BACK! As Editor-in-Chief. Go Craig!!

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