Does traffic growth dictate the need for bigger core routers? Cisco Systems' much-hyped release for its latest souped-up core router, the CRS-3, may lead carriers to think so. But as content delivery network (CDN) services enable operators to push content closer to the edge, the almighty core may become a shadow of its former self.
"The internet is becoming more and more an access process, and less and less a core process. Even the products that are called 'core routers' are usually used as on-ramps [to CDN providers'] data centers," said consultant Tom Nolle, president of CIMI Corp. "The Internet is turning into something else under pressure for content distribution … a federation of metro networks."
CDN service providers -- Akamai Technologies probably the best known among them -- cache popular content within metro areas, meaning that customers aren't going back and forth over the internet backbone to get to Netflix's data centers for every high-definition video they stream, Nolle said.
"The notion that more traffic implies more routers is not necessarily true because all of the traffic that's generated doesn't have to pass through any common set of devices," he said. "If you watch a movie online and I watch a movie online, it's very likely there isn't a single shred of infrastructure on this planet that carries our traffic together … [because] we're in different metro areas."
Although it's faster and cheaper for operators to carry traffic on an optical transport network versus Layer 3 switching with routers, core routers are not becoming extinct, according to Michael Howard, cofounder and principal analyst at Infonetics.
"Most of the router intelligence goes to the edge, and most of the core traffic is carried on optical networks. People have been saying that for a long time," Howard said. "But still, the core router's never going to go away.... You have to have some machine to process IP packets."
But until IP video becomes profitable, upgrading to more expensive and powerful core routers may not yet be worth the investment for carriers, Nolle said.
"Traffic transport is not a divine right, meaning that service providers are going to expand networks and build out infrastructure to the extent that it's profitable," he said. "The notion that traffic drives network deployment is not correct. Revenue drives network deployment."