Metro Ethernet Marches On

By: Richard “Zippy” Grigonis

Ethernet is evolving from old best-effort Ethernet (as found on LANs) to Carrier Ethernet (Ethernet as a service replacing SONET and picking up Frame Relay, ATM and Private Line customers) to Ethernet as a total ubiquitous transport (any media over Ethernet; fiber dominant in core, metro and access areas). At the moment, Metro Ethernet is quite hot. Customers obviously don’t want a best-effort dumb pipe, and are forcing Ethernet to support reliability, complete OAM (Operations, Administration, and Maintenance), QoS (Quality of Service), monitoring and test capabilities in support of SLAs (Service Level Agreements), just like previous generations of transport technologies. Service providers, for their part, are not too keen on replacing $1,000 a month services with $100 a month Ethernet, so they’re searching for ways of providing revenue-generating differentiated Ethernet services. In any case, Ethernet will be the dominant technology service producers use to connect enterprise networks.

Over at ADVA (News - Alert) Optical Networking, Fred Ellefson, Vice President of Applications and Solutions, says, “Ethernet, wireless backhaul, and those markets look like they may not grow the 50 percent per year that people originally expected, but they are still growing. Compared to many other markets that are heading into negative territory for 2009, Ethernet will remain strong. One school of thought that says that as everybody’s budgets get tighter, and they’re looking for things to cut, that could drive them to switch from a $1,000-a-month frame relay service to an Ethernet service that might be $700 or even $500 a month. These economically tight times might actually accelerate movement from telephony services to Ethernet usage. Capital investment is one of the first things that gets hit. As people transit from private line ATM or T-1s to Ethernet, usually you can use the same switch, since that switch already has Ethernet ports, so there’s no capital generally involved.”

“We see three trends,” says Ellefson. “First, NNI [Network-to-Network Interfaces], wholesale Ethernet and mobile backhaul. Mobile backhaul is still a bright spot in the market, though projects originally planned to unfold over two years may now take three years, owing to the economy. But there’s definitely a lot of end user ‘pull’ for data services. The second trend involves the high cost of energy and the need for power reductions. There’s a lot of talk of how to architect ‘green’ networks that have reduced energy consumption. The third trend reflects technology trends and evolution in Ethernet.”

“What’s new and different in this space is that wholesale Ethernet is now a big requirement for mobile backhaul,” says Ellefson. “We’ve had for a long time a User Network Interface [UNI] that’s between a carrier network and an end user or customer premise. Added to this is the idea of an NNI that would go between carriers. Imagine a wireless carrier and a wholesale access provider with an NNI handoff between them, which indicates the need for NNI demarcation devices at the handoff point. In many cases this is quite similar to a UNI interface at the customer premise, but there are some differences: The Link/Service layer Ethernet OAM [802.3ah/802.1ag/Y.1731] is the same for the NNI and UNI. The service layer policing/shaping and definition are similar. But as you get into the matter of protection mechanisms, and things such as throughput testing [RFC-2544], and tunneling and those kinds of things, that’s where you start seeing differences between them. So when you hand off between carriers you might have 100 cell towers that all go through a single NNI between carriers. Losing just one link to one tower is bad, but it’s not the end of the day. However, losing the NNI link that supports 100 towers could knock out most of a city. So there’s a lot more interest in redundancy and in architecting for cable failures as well as equipment failures in that part of the network.”

“A wholesale provider delivering Ethernet services looks to do some sort of transport function or media conversion function,” says Ellefson, “because native Ethernet only travels 100 meters, and when you start talking about cell towers, 100 meters doesn’t get you very far, so you almost always have to convert Ethernet into optics, in the case of 100FX and GbE, or perhaps into T1s or T3s, or maybe over copper-based DOCSIS T1s or NxT1s or radio. They can overlay on top of that some of the key OAM things that have evolved over the last few years: The ability to so do loopbacks and testing, and of course monitoring the SLA [Service Level Agreement] and providing an SLA between carriers.”

Riding the (CWDM) Wave

Atlantic Metro (News - Alert) Communications operates advanced Internet Data Centers and networks throughout the New York Metropolitan area and Chicago. The company also provides managed ISP solutions, colocation, metro transport, IP bandwidth, managed hosting and voice solutions. They provide services to many ISPs, web hosting solution providers, enterprise financial networks, Web 2.0 startups, VoIP suppliers, and carriers. Currently, Atlantic Metro Communication’s global network includes multiple PoPs in Chicago, Dallas, Los Angeles, Minneapolis, New York, Toronto, Canada and London, UK.

James Cornman, CTO, says, “We offer CWDM (Coarse Wave Division Multiplexing) Layer 1 passive waves. It allows our provider and enterprise customers to put their own equipment on the wave and be guaranteed a secure channel — there’s no shared infrastructure, it’s not switched Ethernet, which is what many other carriers offer. We can provide services to carriers on a fully dedicated Layer 1 passive channel. No intermediary electronics are necessary. We provide the optics on either side, which we also manufacture. We can also provide lit Layer 2 Ethernet services via our fiber infrastructure, as well as our WiMAX (News - Alert) infrastructure, seamlessly between any type of medium. We can deliver a 20 Meg tail circuit via WiMAX or you can also bridge that into a building connected at 100 Mbps. Our whole infrastructure nationwide is pure Ethernet; there’s no SONET anywhere in it. Our topologies run the gamut from point-to-point, point-to-multipoint, full ring, and so forth. We offer the CWDM services in Manhattan and metro area.”

“We see our carrier business growing as people increasingly outsource and replace more expensive solutions with converged technology that we offer,” says Stephen Klenert (News - Alert), Atlantic Metro’s CEO. “We see SONET eventually being phased out. MPLS is becoming a bit more prevalent but that’s an independent phenomenon. As a whole, with the offerings we bring to the table, customers tend to hub a lot of connections off one physical port or in other cases multiple ports in different markets or buildings. Overall, Ethernet is a far better platform to grow, particularly considering the current state of the market, with people not wanting to spend as much capital to get the bandwidth they need.”

Fabulous & Fabless

New, high bandwidth Carrier Ethernet requires new kinds of Ethernet chipsets, such as those made by Xelerated. Their Xelerated Dataflow Architecture delivers wire-speed deterministic performance, and is used by many Tier-1 carrier networks worldwide. They appear in many Metro, Access, and high-end enterprise Ethernet deployments. Xelerated recently announced its HX300 family of network processor units, said to be the industry’s first programmable Ethernet switches to the fiber access market – enabling the mass deployment of fiber to just about anywhere.

Then there’s Lightstorm Networks (News - Alert), which likes to point out on its website that, “95 percent of the world’s data traffic starts and ends as Ethernet – but carrier networks predominantly use legacy technology to transport data traffic that is encapsulated in connection-oriented protocols.”

Lightstorm, a fabless semiconductor company founded in 2004, aims to do something about that. They design, develop and supply complete semiconductor solutions as well as provide hardware and software subsystems. They’re focused on the Carrier Ethernet segment. Indeed, they’ve built a family of Applications-Specific Semiconductor Products (ASSPs) unique to Carrier Ethernet.

Wade Appelman, Vice President of Sales and Marketing for Lightstorm, says, “The market now understands that you can’t take enterprise Ethernet silicon and apply it to the Carrier Ethernet application. Silicon has traditionally been around from Broadcom or Marvell (News - Alert) – and there a lot of what I would like to call Carrier Ethernet 1.0 applications that have used such silicon and they’ve wrapped FPGAs [Field-Programmable Gate Arrays] around it, or they’ve used network processors to build products. But those have a cost and power consumption associated with them. So the trend we’re now seeing is for people wanting to add the new Carrier Ethernet features like OAM, performance monitoring, network synchronization and timing, and they need to have a new type of device that you can’t build with enterprise silicon components. That’s why we’ve focused on this new generation of technology. We launched our first product back in the fall of 2007 and have been sampling it in earnest since the beginning of 2008, and now customers are far along in their designs so we can announce them.”

In November 2008 Lightstorm announced the Brooklyn-XLA family of Carrier Ethernet access switches. Equipped with an integrated traffic manager, the Brooklyn-XLA leverages IP from the Lightstorm purpose-built carrier Ethernet switch, the Brooklyn-10, and extends features to address Ethernet access platforms in the wireless backhaul, network termination and service demarcation space. The Brooklyn-XLA family provides packet buffering, TM/QoS, timing synchronization, carrier Ethernet protocols, OAM processing, and scaling to handle the MAC “explosion” currently occurring in provider networks.

The Brooklyn-XLA is complemented by a sophisticated carrier Ethernet software suite based on the Brooklyn-10’s Ethernet API. It includes development tools for rapid device configuration, statistics monitoring, and packet viewing. To aid in an OEM’s time to market, a complete hardware development environment is also available.

Major equipment providers, such as ZTE Corporation, recognize the advantages of a carrier class architecture, and they’ve selected the Brooklyn-10 for an upcoming IPTV (News - Alert) application.

Meeting of the Minds

Overture Networks develops packet-based, multi-service access platforms that allow carriers and enterprises to deliver TDM and newer Ethernet-based services over existing current revenue-producing infrastructures. Overture has designed a single carrier-class platform that can run multiple managed services over any wire at the customer edge. This infrastructure-agnostic platform allows carriers to offer advanced revenue-generating and managed Ethernet services, reduce costs considerably while retaining the transport efficiencies and reliability of SONET/SDH, protect investments by allowing quick field upgrades and new service rollouts without massive changes to the network, and ensure compatibility with next-gen architectures.

Recently, Overture acquired Ceterus (News - Alert) Networks and its product portfolio, including the optical Universal Transport Solution UTS 4000, that boosts Overture’s presence in two hot Ethernet market segments: wireless backhaul and Carrier Ethernet services.

Dave Stehlin, the new President of Overture Networks (News - Alert), says, “There are challenges that come with the transition from TDM to packet-based infrastructures. Still, it’s possible for carriers to leverage multiservice solutions to reap revenue. Certainly the combined Overture/Ceterus company addresses two very key aspects of all this: One is Ethernet-to-Enterprise for business services; the other is cell site backhaul, as all of the major carriers are moving toward an Ethernet-based network. In essence, 100 percent of all the cell sites around the world will have to be upgraded to handle Ethernet.”

Overture’s CEO, Jeff Reedy (News - Alert), says, “Our strength has always been in the Carrier Ethernet solutions for business services, both at the network edge in a building’s basement as well as back in the CO at the aggregation points. We saw a need to deliver Ethernet to cell towers too, and Ceterus is certainly the strongest player in that market. Combining our expertise and compatible technologies makes perfect sense, sets us apart from the pack, and really is in response to what the carriers are asking for – a one-stop shop for Carrier Ethernet solutions at the network edge.”

“Carrier Ethernet is certainly going to be affected by the current economic situation, but not as much as many of the other services out there,” says Reedy. “At the end of the day, Ethernet is a more efficient and cost-effective way to deliver bandwidth. Moreover, everyone is demanding more bandwidth. If carriers are expected to grow and build their business, they really don’t have a choice other than put more and more emphasis on Carrier Ethernet. That applies both on the business side and the cell side.”

Ethernet is Everywhere

Ethernet is becoming a universal transport. It’s on the backplane. It’s on the LAN. It’s now in access networks and soon may dominate the network core. Just about the only place you don’t find it is running between chips where nimbler switch fabrics such as RapidIO (News - Alert) play. Even so, I won’t say that Ethernet will never find a way to run in that space too. Ethernet continues to surprise us. IT

Richard Grigonis (News - Alert) is Executive Editor of TMC’s IP Communications Group.

ADVA Optical Networking (News - Alert) – (www.advaoptical.com)

Atlantic Metro – (www.atlanticmetro.net)

LightStorm Networks – (www.lightstormnetworks.com)

Overture Networks – (www.overturenetworks.com)

Xelerated – (www.xelerated.com)

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