"The 'core router' announcement they made is an edge router, not a core router," said Rob Lloyd, senior vice president at Cisco Systems Inc. (Nasdaq: CSCO), during the company's recent Cisco Live event. "It doesn't have multichassis. It doesn't have the scale and the capacity that's used in core routing today."
Not true, Alwan says.
Alwan is in charge of AlcaLu's IP and optical divisions, but he's also the former CEO of TiMetra, the acquired startup. He's certain his team -- which has focused on the same architecture for about a decade and watched its baby grow up to be the industry's No. 2 edge router -- has built a core router. And he's damn proud of it.
"It's been eight years since I've done anything this meaningful in the industry," Alwan says.
Counting past one
Announced late in May, the XRS is like a giant version of the successful 7750 Service Router, in that it uses the same packet-processing chip and the same software.
Its most obvious difference over the 7750 is size. The XRS-20, a single chassis taking up a seven-foot telecom rack, can theoretically support 16Tbit/s of traffic (8Tbit/s if you're not double-counting), with each of 10 slots able to handle a theoretical 1.6Tbit/s (800Gbit/s).
But what about Cisco's "multichassis" dig? Well, AlcaLu has announced a two-chassis version, the XRS-40, due to come out next year. Larger multichassis systems will be available when AlcaLu ships a switching shelf, an extra piece of equipment that would be the switch fabric connecting all the other chassis. No shipping date on that has been announced yet.
So technically, AlcaLu has no multichassis XRS shipping at the moment. But Alwan points out that that never stopped anybody else's marketing team. "Every Cisco and Juniper platform that I know of came out with a single shelf first, and they were still considered core routers," he says.
He's got a point. In 2004, Cisco made a huge deal out of the potential for a 72-chassis CRS-1 router, even though it wasn't clear that 72 of the boxes had ever been built at the time of the announcement.
Along those lines, Alwan also challenges the idea that carriers want dozens of routers hooked together in multichassis fashion in the first place. Eight chassis seems to be the maximum so far, and only in rare cases. The 72-chassis version is "a crazy spreadsheet exercise that's never going to be built," Alwan says.
Cisco officials correctly point out that they've led the multichassis core-router market. The thing they expect will trip up AlcaLu, Juniper and others is the scaling of the control plane to work across so many boxes. Alwan says that's hogwash and AlcaLu already knows its control plane will scale just fine.
But Cisco still expresses doubts.
"I would love to find out how that works, with an operating system that's 10 years old," says Suraj Shetty, a Cisco vice president of marketing.
Juniper doesn't think the scalable control plane is they key problem for anybody's multichassis router. "The control plane doesn't really have anything to do with that. It's the interconnect technology, bringing the switching in and out [from one chassis to another]. That's the gating factor," says Luc Ceuppens, vice president of product marketing. He adds that the task has been made easier by the introduction of pluggable optics.
Then there's the factor of density -- how much traffic the router can deal with. AlcaLu says the XSR has an industry-leading density and blows away Cisco's in particular.
Naturally, Cisco disagrees. Here's one way to sift through the numbers.
The full-rack XRS-20 is a 20-slot box. It's designed to let that port capacity grow to 20Tbit/s eventually, but the first available cards will have only two 100Gbit/s Ethernet ports per slot. That multiplies out to 4Tbit/s of port capacity per rack.
The largest Cisco CRS-3 has 16 slots. Even at 200Gbit/s per slot (a 20-port 10Gbit/s Ethernet card, which appears to be the highest-density card available), that's a port capacity of 3.2Tbit/s.
Cisco counters this one by comparing the XSR to the ASR 9000, an edge router that actually has higher density than the CRS-3. The ASR 9922 has 20 line-card slots and an available card with two 100Gbit/s ports, matching the XRS-20. Of course, the ASR 9000 isn't a core router. Even Cisco doesn't call it one.
So, whether the XRS's density is a big deal depends on which category you want to put it in -- as a core router, against the CRS-3, or an edge router (as Cisco would prefer), against the ASR 9000.
(It's worth noting that density comparisons are always tricky, because every vendor wants to compare different things. Feel free to offer up your own comparisons on the message board below.)
In part, the arguments just reveal that the lines between core and edge networks are getting fuzzier. Carriers themselves have different ideas about what has to be in the core or the edge. Virtualization and video traffic (think CDNs) are making the metro network a bigger and busier place, needing core-like densities in some cases.
And every major vendor has a plan to handle it all. Cisco is still in the leader's position for now and doesn't think any of these trends will change that.
"How many of the competitors you have asked us about have maintained sustainable market share from Cisco?" Chambers told the press at Cisco Live. He added that Cisco managed to gain eight points of market share in edge routing during the past 12 months, a sign to him that AlcaLu is "really exposed, make no mistake. We're going to go after the edge router, because we don't see very many customers that can put this in the core."
AlcaLu sees it differently.
"The gap between the XRS and the competition is, I think, the big story," Alwan says.
- Verizon Builds an MPLS Metro With AlcaLu
- What's So Big About CRS-3?
- Cisco Boosts the Core With CRS-3
— Craig Matsumoto, Managing Editor, Light Reading