Alison Adams, Virgin Media Business: ethernet has become the
de facto access technology within the whole metro area 
                                               
                                               

                                               
James Walker, Tata Communications: at a metro level the
ability to provide a highly scalable service is key 
                                               
                                               
For a technology that started out linking desktop terminals with each other and servers within single location offices, ethernet has come a long way in a short time and is now being relied upon to become the high bandwidth transport protocol that underpins the internet and the routine high bandwidth services that users of all types demand.
The technology has developed from those humble roots into the access and metropolitan network domains and, more recently, is becoming the long distance technology of choice thanks to its low cost of operation and its potential to deliver massive capacity.
“Ethernet has absolute relevance across all of the domains,” says Martin Brundert, head of IP transport solutions management at Nokia Siemens Networks. “The clear trend industry-wide is that ethernet is being deployed. Ethernet roll-out is happening now and happening in volumes.”
It is necessary, however, to view ethernet deployment across those domains — the access, metro and long distance markets — to establish how it is being deployed. It hasn’t taken over the world yet.
“Ethernet started inside the enterprise LAN,” points out Chuck Kaplan, vice president of portfolio solutions at Ciena, who explains that from a telecoms point of view ethernet has evolved from the outside of the network inwards to the core. “In the early days, it wasn’t reliable enough to be carrier class so companies like us have wrapped additional technologies and ways of looking at how packets are being passed and service level agreements are met.”
That view is shared by Alison Adams, head of VPN and security at Virgin Media Business: “I don’t see too many challenges in terms of ethernet access,” she says. “We’re starting to see much more intelligence in those areas and more intelligence in the customer premises equipment. That will ultimately be much less disruptive for customers. The opportunity is going to be much more around things like application performance management and assured service delivery being enabled because there’s much more intelligence.” 
                                               
                                               
Transport technology 
                                               
Kaplan adds: “When it comes to metro, you’re really starting to see ethernet as a transport technology,” he says. “Virtually everyone agrees ethernet is the right technology because increasingly the format of data coming out of the data centre is at layer two ethernet packets so the most cost effective method is to transport at layer two as a flat network.”
James Walker, vice president of managed network services at Tata Communications, thinks that is critical, especially in the metro market. “Particularly at a metro level the ability to provide a highly scalable service, both in terms of throughput and in terms of sites which are connected to the network, is key,” he says. “Where this is provided over either a layer one (SDH) or layer three (IP/MPLS) network, scaling issues becoming increasingly problematic and restrictive for the customer’s desired network topology, particularly if they require direct interconnection of large data centres. Having that ability to also scale regionally or globally means that the customer’s data centre requirements can be delivered on a globally unified platform.”
To that end, Tata Communications has rolled out its second generation carrier ethernet platform which uses provider backbone bridging technology. PBB solves many scalability issues existing in ethernet services and provides a seamless, integrated, single technology platform for metro, regional and global requirements.
It allows virtually unlimited scaling of MAC addresses and VLANs, providing a strong base for the development of virtual data centre services and private clouds and indeed a whole new class of enterprise data services, saving customers the cost and complexity of operating a routed IP network.
“Compared to MPLS, ethernet offered using PBB brings greater capability to offer extremely scalable multipoint services locally and globally, 10 gigabit ethernet services, deterministic routing and protection, and greater security,” adds Walker.
“There are significant benefits in terms of cost reduction through the use of layer two switches instead of layer three throughout the network, and reductions in complexity of network management. Layer two services also bring very significant advantages over MPLS in terms of core convergence times when a cut is experienced in the provider’s network core.”
Adams at Virgin Media Business says the technology has now truly arrived in metro markets. “It’s become the de facto access technology within the whole metro area,” she confirms. She sees two types of ethernet deployment. 
                                               
                                               
Security of transmission 
                                               
“There’s the native type for the metro area that addresses relatively short distances and is a relatively old service,” she adds. “Demand is very high. Benefits include the security of transmission is high and the latency is low. It’s also attractive for organisations that like to do a bit of self build. The other flavour is switched optical and now we’re looking at VPLS ethernet going much further afield.”
Larry Socher, global lead of the networks practice at Accenture, agrees: “In the metro and distribution networks, ethernet is the emerging de facto standard.” But it wasn’t always that way, says Socher, who points out Token Ring technology might have displaced ethernet.
“Token Ring was clearly better technology in the same way Betamax was in comparison to VHS,” he says. “It is deterministic which means it is better to do quality of service with but it was more expensive. You can get to much better economics with ethernet and get to much bigger bit speeds.”
Jeff Schwartz, group manager, global ethernet product marketing at Verizon Business, takes the cost advantage point but emphasises that’s not all ethernet has to offer. “Yes, ethernet is very efficient and competitively priced from a per-megabit perspective, but we don’t typically lead with ethernet being cheap,” he says.
“We lead with it being robust, with an efficient cost model, with class of service supported by a service level agreement that typically meets even the most demanding applications that our customers require.”
Robin Tero, service provider service development director at Interoute, sees a range of technologies coming together that enhance the usability and capability of ethernet.
“Providers continue to see a massive migration to IP as the universal language and whether it is data, video, storage mobile, voice or cloud computing services, ethernet has become the universal transport layer driving convergence to a single technology with the access/metro environment,” he says.
“As well as native ethernet switches, devices now support ethernet emulation over technologies such as TDM and DSL. And with the addition of carrier ethernet features they can support consistent, transparent, reliable and pre-determined connectivity that was traditionally only available with TDM circuit switched networks.
“Within core networks where aggregated connectivity drives higher bandwidth demand, it can be carried natively or within an OTN layer with the option to switch at either the packet or optical level and again can support carrier class service performance if so enabled. In fact, demand has driven new standards in 40 and 100 gigabit ethernet.” 
                                               
                                               
Viable proposition 
                                               
For Tejaswini Tilak, global head of carrier services at Telstra International, ethernet’s long distance reputation is still being established. “Ethernet deployment in enterprise networks has a long history, but it is just in the past two years that the technology has become a viable proposition over international networks,” she says.
“As enterprises are increasingly looking to use high-bandwidth services — from VoIP to telepresence to multimedia streaming — between regional offices around the world, this is a significant development. Not only does ethernet enable added efficiencies and simplicity of use compared with legacy network technologies but it also allows companies to control WAN costs despite these rising bandwidth requirements.”
But, she warns: “However, despite its promise, the global market for ethernet WAN services is still in its infancy. It is certainly gaining traction but the market needs to mature significantly — especially in terms of availability, interoperability and standardisation — if these expectations are to be met, and the technology becomes a viable solution for enterprises to meet the challenges of the bandwidth explosion.”
Before 2008, the lack of ethernet WAN services over wide geographical ranges had been a major hindrance but, in the past three years the situation has improved significantly as providers have increased the geographical scale of their offerings. This has led to ethernet exchanges becoming of increasing importance.
“The general barriers that every service provider has continue to be in establishing and deployment of OAM — operations, administration and maintenance — technologies to provide even more robust ethernet monitoring,” says Schwartz.
“This is where you see ethernet exchanges coming into play. We have more than 200 relationships already globally. Verizon has really focused so those access providers we use when we go off net meet our very rigid programme. It is and has been the biggest roadblock in general to getting past this perception of global access limitations. As an industry that is now being addressed.
“We’ve already done that work but ethernet exchanges will provide these other carriers with means to substantially increase their capabilities and do it fast by integrating with CENX, Telx and others.” 
                                               
                                               
Seamless and transparent 
                                               
Tilak at Telstra International agrees: “The environment for ethernet interconnection will be a critical factor if the market is to mature as required,” she says. “There needs to be a standardised, seamless way for providers to interconnect with each other. This will produce quicker processes, and in turn, more seamless and transparent services to end-customers.
“New ethernet exchanges are popping up in data centres around the world, aiming to simplify ethernet external network-to-network interconnection (E-NNI). Prior to these exchanges, carriers have had to manage interconnection arrangements on an individual basis – a lengthy and unnecessary process which has in turn impacted the end-user proposition.”
However, Tilak thinks the business models of these ethernet exchanges will need to mature if they are to have the required impact on the market. “Some providers are still going it alone, put off by restrictions in ethernet exchanges’ ordering, billing and processing features,” she adds. “The ethernet exchanges themselves must continue to develop if they are going to help ensure the global interconnection of all the major ethernet carriers.” GTB