SONETs Not Going Away
Still, SONET will be around for quite a while because Gig-E remains out of reach for most. There may be a glut of fiber in the long-haul network connecting metro areas, nations and continents, but there is a profound shortage of fiber connecting businesses to metro networks. Perhaps 5 percent of businesses have optic fiber to their buildings, according to market research firm IDC."The entire market is limited by availability of fiber to the end customer," said Sterling Perrin, an IDC analyst. "Until they get fiber to them, theyre not going to have Gigabit Ethernet to the network."Even if copper could handle gigabit speeds over distance - or even if optic fiber wasnt beyond most budgets - most enterprises need nothing like gigabit speeds, Perrin said. Today, most connections from businesses to the public network are at T1 (1.5-Mbps) speeds. Six years from now, three-quarters of the connections to businesses still will be about one-sixth of a gigabit, according to Ovum. Enterprises can wait weeks to get bandwidth upgrades from a SONET cloud, and the company that wants just a little more than the 1.5 Mbps it has now can be forced to get - and pay for - 30 times its old capacity. And yet, SONET endures. SONET is an optical standard with the flexibility to transport many digital signals of various capacities from different vendors. Developed when voice was the dominant traffic, it features huge rings around metro areas that carry conversations - and data - with high resiliency and very low latency. The very fact that its expensive and durable keeps it from fading away, despite its unsuitability for data and its labor-intensive upgrades. "The beauty of SONET is that, OK, its old and expensive, but it works, and its ring architecture is simple, even if its inefficient," Ovums Main said. SONET has been proven to handle both voice and data traffic with little latency or jitter, something Gig-E hasnt proven on a metrowide scale in the real world. At $200,000 for one OC-192 SONET-style switch, incumbent carriers such as the former regional Bells wont dismantle their voice-based SONETs until they wear out or until Gig-E proves overwhelming economic superiority. The wind seems to be blowing in favor of SONET, too. The MEF is moving toward a standard that would let Ethernet frames be carried over several technologies, such as SONET, dark fiber or Wavelength Division Multiplexing, the MEFs Klessig said. "That would let the regional Bells build networks using Ethernet switches part of the way, while maintaining their SONET infrastructures," he said. "Its pretty clear a lot of carriers that have that installed [Asynchronous Transfer Mode or SONET] base want to do a gradual migration" to Gig-E, he said. "The thinking is that by having high degrees of interoperability over several infrastructures, all boats will rise in the water." That leaves the pure Gig-E players such as IntelliSpace, Telseon and Yipes with less of an advantage than they might otherwise have had. But with standards that promote universal interoperability, new and old players can more easily connect to "technology-agnostic" equipment and networks. That likely would usher in a hybrid world, giving end-to-end elegant Gig-E to a few large enterprises, while the rest enjoy some cost savings and cool new applications from their Gigabit-somewhere-some-of-the-time networks.