Core routers: time to grow up

Telecommunications Americas, Nov, 2004 by Jim Barthold

As the telecom industry thaws from its bitter nuclear winter, it's apparent that real-time IP-based applications are going to generate the new revenues. It's also apparent that old-time best-effort core routers, designed when computer crashes were as common as Florida hurricanes, won't do the job. Telephone companies are demanding telephone dependability from applications that were never meant to be run over telephone networks and core routers are being asked to make it all happen.

"The core router of the previous world was primarily driven by just data traffic and just one class of service. As we start converting the Layer 3 network into a more revenue-generating network, you're trying a bunch of new product offerings--voice, VPN, etc.--and the expectation is that this be the same carrier-class type of network," said Balan Nair, CTO of Qwest Communications.

It's not as if the router vendors were taken by surprise when carriers started issuing increasingly picky RFPs for new-age core routers. IP's importance as a part of the telephone network was growing even as the carriers slumbered and regrouped. Vendors who were twiddling their products, not their thumbs, during telco's big chill are pushing forward a new breed of IP-dependable core routers.

"Carriers increasingly want the reliability to be built into the system. It needs to be internal to the system, which is very much of a telephony model," said Esmeralda Swartz, vice president of marketing for Avici Systems.

Carriers also want the seemingly impossible: no down-time. "There's no such thing as a convenient maintenance window these days; you have global customers," Swartz said. "It's not convenient to perform a software upgrade in the middle of the night or on a weekend."

At the same time, software upgrades are part of the IP life. "You need to be able to walk up to the machine and do a complete in-service software upgrade and not drop any packets," said Ken Lewis, CEO of Chiaro Networks.

And that, he said, is something that's completely new for both the IP and the telephony space. "There are generations of routers in the market today that reboot about as often as your PC does," he said. "They have to get away from that."

Chiaro, being relatively new to the space, is not encumbered by old-line router thinking or design. It used the industry slump to perfect its business model and product design.

"It gave us a chance to finish the product and do it right," said Lewis, who saw yet another benefit to the telco freeze. "In the process of us getting ours finished, a lot of competitors have died."

The biggest players--Cisco and Juniper--didn't go away, though, and they're scrambling to meet the needs of the changed space. Juniper, for instance, is pushing a function called "graceful restart" that lets operators continue forwarding traffic while going through a system refresh.

"Three years ago, when the router control plane restarted it typically stopped routing, stopped forwarding traffic and any traffic over it was dead and you had to wait for a network reconvergence," said Matt Kolon, Juniper's senior marketing manager, noting that this is unacceptable with real-time applications like voice and gaming running on the IP networks.

Juniper also advocates "redundancy in the core routers," adopting the age-old paradigm that having a back-up is better than not having a back-up.

Kolon agreed that router vendors must change their thinking, but pointed out that's a two-way street because "if you think about IP on the one hand and TDM on the other, they're completely different things."

Certainly Avici's thinking about things differently, including redundancy. "We're proposing migrating to a single router model. You can do that if you deliver the reliability in a single system," said Swartz. "From a capex perspective, there's a cost savings from eliminating redundant layers and eliminating redundant routers."

The technology of core routers may still be evolving, but the economics that will drive their development are chiseled in account ledgers: They must be reliable, cheap and last a long time.

"Upgrading the core is a very expensive proposition," said Qwest's Nair. "If not for new revenue-generating traffic, I don't think any company can go out there and justify it." The grown-up products must last for "at least the next five years," Nair said.

It is, as the most recent carrier RFPs have shown, a tall order, but "vendors are capable of delivering," said Mark Bieberich, a program manager for the Yankee Group who specializes in routers and switches. "Obviously there are going to be some bumps in the road, but two years from now I expect the rate of innovation to improve even more."

Market Leaders
Worldwide 10 Gbps Router Market

Total 10 Gbps           Quarterly
Market            2004  Growth

MFG Revenue ($M)  $260  13%

                        Quarterly
Vendor            Rank  Growth

Cisco Systems     1     16%
Juniper Networks  2      7%
Avici Systems     3     79%

Source: Dell'Oro Group