Meriton unveils Carrier Ethernet Transport strategy

Feb. 5, 2007
FEBRUARY 5, 2007 By Meghan Fuller -- CET, as defined by Meriton, is an architectural approach for building a scalable transport infrastructure for supporting Ethernet and the evolution to next-generation networks.

FEBRUARY 5, 2007 By Meghan Fuller -- Meriton Networks (search for Meriton Networks) today announced its strategy for entering the Carrier Ethernet Transport (CET) market, which analysts forecast to be a multi-billion dollar market over the next three years.

According to COO Bill Gartner, Meriton's decision to enter the CET market is a direct result of what he sees as the increasing ubiquity of Ethernet. "In our own business, GigE is becoming the new currency of exchange in the network," he notes. High-end applications like video-on-demand (VoD), video telephony, and gaming dramatically increase the bandwidth needs and service level requirements, and Gigabit Ethernet (GbE) has emerged as the ideal transport mechanism for these applications, says Gartner.

He predicts a "phasing out" of SONET/SDH--at least as the transport architecture--in favor of an Ethernet over WDM or ONT-type approach.

What is CET?

CET, as defined by Meriton, is an architectural approach for building a scalable transport infrastructure for supporting Ethernet and the evolution to next-generation networks. It integrates Ethernet tunneling via Provider Backbone Transport (search for PBT) or Transport MPLS (a subset of MPLS) into the intelligent WDM layer.

"Basically," says Gartner, "you have a very flexible optical layer that includes switching capabilities at the wavelength and sub-wavelength layers. And you have just enough--and that's a key point--just enough Layer 2 capabilities to be able to provide an end-to-end Ethernet service, but not burden the optical layer or the transport layer with a lot of the Ethernet Layer 2 functions. You can think of it as a transport problem," he says.

CET enables a separation of the service delivery architecture from the underlying transport architecture. By doing so, the transport network is transparent for service creation and modification (e.g. adds, moves and changes). In other words, the transport layer is responsible for transporting traffic from point A to point B; it provides end-to-end capabilities for Ethernet reminiscent of circuit-oriented capabilities of SONET/SDH.

The optical layer capabilities include wavelength switching (any port to any port), sub-wavelength (typically GbE) switching (any port to any port), and Carrier Ethernet Tunnel switching (any port to any port). Again, just enough switching capability is embedded in the optical layer to eliminate all the inter-port handoffs between the service layer and the transport layer, says Gartner.

In other words, CET eliminates an unnecessary handoff between the transport and service layers. Say you have a handoff between the transport layer and the service layer, but where that handoff would occur, the service layer says, "'That Ethernet is really directed downstream from where you just handed it off to me,'" explains Gartner. "If we could make that decision locally in the transport layer, we could eliminate a number of Ethernet interfaces on these boxes. We are more efficiently looking at the optical signals as they pass through the transport layer and saying, 'If it's not necessary for that signal to go up to the service layer so that it can be switched, we're not going to send it up there.'"

For his part, Gartner believes the CET story will resonate with carriers because each eliminated Ethernet interface represents a cost point for the carrier. Moreover, he believes alternative architectures, including an Ethernet overlay model or IP over DWDM, struggle with scalability issues, cost issues, and especially with what he calls "organization alignment. They force the data organizations and the transport organizations to make peace with each other or give something up," he says, "and that is politically difficult to do."

Phased rollout

According to Gartner, Meriton's rollout of CET capabilities will occur in two phases. Phase one enables carriers to support high-density GbE networking within the metro using sub-wavelength switching (SWS) and grooming of nine GbE streams onto a 10-Gbit/sec wavelength. The capability of switching a GbE path within the optical transport layer, maintaining the path throughout the entire network, and assuring it with a Service Level Agreement (SLA) makes it ideal for wholesale interconnect services, says Meriton.

Phase two will introduce support for Carrier Ethernet Tunnel switching and aggregation for local handoff. The first Ethernet tunnel technology to be supported by Meriton will be Provider Backbone Transport (PBT), which is currently undergoing ratification within the IEEE, under the proposed name of Provider Backbone Bridging -- Traffic Engineering (PBB-TE).

Meriton is collaborating with Danish company TPACK to add PBT-based Carrier Ethernet Tunnel Switching to the 7200 Optical Switching Platform (OSP), Meriton's 320-Gbit/sec integrated switching and transport system. Together, the companies are developing an Intelligent Ethernet Gateway (IEG) that will be an optional component of the 7200 OSP.

Gartner says he sees the initial take for the CET-enabled 7200 OSP outside of North America, particularly in Europe where BT's recent announcement in favor of PBT has turned the spotlight on the technology. However, the company will be marketing its new CET strategy worldwide.

Meriton's CET functionality on the 7200 will be available in the second half of 2007.

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