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Metro Ethernet is a Hit

By: Richard "Zippy" Grigonis

Ethernet is everywhere. Appearing first in the LAN, then on the rackmount backplane, Ethernet can now be used both as a Metropolitan Access Network (MAN) to connect subscribers and businesses to the Internet and by enterprises to connect branch offices to their Intranet. Unlike older TDM-based technologies, Metro Ethernet supports high bandwidths with fine granularity. Bandwidth can be dynamically altered if necessary. Since it’s Ethernet, it can be connected to your network without much fuss. On a MAN, Ethernet can take the guise of Ethernet, Ethernet over MPLS, Ethernet over SDH, or Ethernet over DWDM (Dense Wavelength Division Multiplexing). There are even ways of squeezing some additional bandwidth out of existing copper lines instead of resorting to optical fiber.

Recently Yours Truly looked at Matisse Networks (News - Alert)’ EtherBurst, said to be the world’s first Packet WDM System, purpose-built for scaling metro and campus networks. The EtherBurst Packet WDM System includes the SX-1000 Ethernet Service Node (these nodes serve as both a local Ethernet switch and the on-ramp to the packet WDM photonic layer), the PX-1000 Photonic Node (these nodes are deployed in a metro ring, and provide a fully automated optical layer, enabling incremental scaling) and the MatisseView Management System, which provides unified access to integrated optical and packet service management software.

EtherBurst is just another example of how carriers have finally tried to stop selling ATM to their business customers and are now giving them what they’ve wanted all along – Ethernet in the Wide Area Network (WAN), particularly in metro segment between the last mile and the network core, which is still dominated by MPLS.

End-to-End at Layer 2

ANDA Networks (News - Alert) provides innovative carrier-class Ethernet equipment solutions for delivering cost-effective Metro Ethernet services over fiber, copper, and wireless based access networks worldwide serving a key role in Maximizing Ethernet Service Reach for our carrier customers worldwide.

ANDA Networks Greg Gumm, Vice President of Marketing and Business Development, says, “From a market perspective, there are various reasons Ethernet is being deployed so heavily. What is the common interface sold today? Ethernet is found on your desktop PC, handheld devices, wireless Ethernet on phones, and so forth. Clearly Ethernet is the dominant interface. From a technology and production perspective Ethernet has clearly been a ‘high runner’ in terms of a common interface standard. There’s clearly a proliferation of the chipset, the standards and the ability to have large volumes of either virgin silicon or interface boards with that type of interface available. Every router and switch that’s out there today typically will have some type of Ethernet interface on it as a standard component. It used to be that you had to plug in an Ethernet card. But now PCs now all have 10/100 Mbps and Gigabit Ethernet that’s standard on a Dell (News - Alert) or Apple computer.”

“Clearly, all of the LANs today are Ethernet,” says Gumm. “When you start moving out of the LAN into the WAN, in the past we used services such as Frame Relay or private line services or, way back when, ISDN to actually provide transport to traverse the Wide Area. What’s happened now is that the LAN people have said, ‘Everything behind the WAN is Ethernet, so why would we not use Ethernet in the WAN?’ If you’re Customer A and I’m Customer B (News - Alert), and we want to talk to each other, you’re in New Jersey and I’m here in Sunnyvale, California, in the ‘normal’ way of doing it, the typical plan was that outside of the LAN you had a router, from that router you then needed some kind of private line or frame relay lines. Or you might have a city ring, such as an FDDI ring or some kind of OC-3 SONET connection into the Internet POP or service provider. And that allowed you to have a connection. That also meant that you had to have conversions of the frame relay or the ATM, or whatever you’re using and, on the other side, convert that down from the router and then convert that to Ethernet so it could point out to your PC.”

“So basically, the value proposition is pretty easy when you move Ethernet into the WAN,” says Gumm. “Instead of playing ‘follow those legacy switch converters’, protocol converters that are doing conversion of frame relay and ATM back down as Ethernet, you can now remove those network elements and the protocol conversion and do Ethernet all the way through, Layer 2 Ethernet end-to-end. That allows you to have a more simplified network, which means fewer network elements and less cost. It’s also a more common interface so the equipment costs tends to be less, because there’s more volume production in these types of products – high volume runners.”

“Essentially, the market centers on business broadband,” says Gumm. “We may not hear much about it but, just as we have residential broadband craze, clearly business broadband is also taking off quite nicely, primarily because of the Ethernet delivery services capability that the carriers and others will offer because of all of those economic reasons, and also because customers would prefer to have a native Ethernet connection into their point of presence. I’d say if you take a look at the list of the top 100 carriers in the world based on revenue, I believe that about 90 percent offer or are planning to offer Ethernet services.:

“We originally started out developing some voice gateway equipment when the carriers were looking to deliver voice over DSL,” says Gumm. “Based on the market conditions after the big crash in 2000 or thereabouts, we decided to refocus the company on delivering Ethernet access equipment. We saw the move to delivering converged voice and data and video over wide area transport. That was also coming along with the rise of VoIP, of which we’ve seen a fair amount. As services such as VoIP and streaming video start to hit these networks, frame relay and private lines are not very good at handling delay sensitive traffic. You don’t want to be talking on a VoIP phone and then have it clip out. You can’t afford to lose a lot of packets. You can’t have a lot of delay in the network. Real time traffic is very sensitive. So when you move to Ethernet, that provides not only a universal interface, but a good medium to deliver integrated or converged voice, video and data traffic over a Layer 2 service. And that’s another major reason why ANDA decided to get into the market back then. We have a fair amount of voice and data experience and we saw that things were going to be converging over an Ethernet transport.”

“We have developed a full suite of metro Ethernet products,” says Gumm. “Our boxes are deployed at business customers’ premise, and then upstream from that we have an aggregation box that takes in all of the business locations. Our EtherEdge 4000s can aggregate all of the Ethernet traffic into a much larger pipe and then feed that data traffic into larger switch routers such as a large Cisco (News - Alert) routers, or those from Juniper or Alcatel. If you think about it, it’s very similar to how DSL was deployed in the residential area. You had DSL modems on the premises and you had DSLAMs at the edge to aggregate the traffic and take it to the network. So we have a set of products called EtherReach, which are in our premise boxes that sit at the business customer’s premises and then we have products such as our EtherEdge or our EtherSLAM product which does the aggregation of those boxes and then takes all of that Ethernet or VLAN traffic into a larger switch router. We sell directly to large tier 1 and 2 carriers worldwide. Bell Canada is a customer, as is Level 3, XO Communications (News - Alert) and most recently we won a fairly large tender with British Telecom for their 21CN Ethernet network. Those are some of the carriers to which we supply this gear. They take our gear and put it into their network as infrastructure to deliver their Ethernet services. Our boxes are used to enable their global Ethernet services for international Ethernet private lines, ELAN services, and point-to-point or multipoint services that they provide to their business customers.”

“One big driver moving Ethernet services is clearly the convergence of VoIP streams – streaming video and data,” says Gumm. “About a year ago, Verizon (News - Alert) won a very large deal with Chicago Mercantile Exchange. In about 700 locations they needed to terminate an Ethernet service because they wanted their traders, who are commodities traders, to access not only their email and their corporate databases but a big application for them which involves able to converge their VoIP phone service and streaming video. One main application was being able to quickly see what’s happening on the trading floor, where’s the market going. All of the applications had to run seamlessly over one type of WAN connection. They wanted the same type of capabilities in a consistent manner across all of their locations. So Verizon rolled out an Ethernet service to all the locations, a very big deal. They won over AT&T, which was bidding frame relay, private line type services. Verizon won that deal primarily because of their ability to provide Ethernet to all of the locations and to handle the delay-sensitive applications being converged over Ethernet service.”

“ANDA equipment can provide Ethernet over both TDM circuits and fiber,” says Gumm. “That allows the carrier – in this case, Verizon – to offer Ethernet service fairly ubiquitously. Their reach is close to 100 percent. There aren’t too many places they can’t get to thanks to our equipment, either over copper circuits or over optical fiber. Only about 13 to 15 percent of the business buildings in North America are actually directly fiber connected, so supporting copper facilities is important.”

Making the Grade

Ciena Networks provides flexible platforms, intelligent software and professional services to build converged networks for enhanced services and applications.

Dave Parks, Product Marketing Director, “We’re focused on Ethernet and see many opportunities in this market. It’s a big growth area. Our customers are investing heavily in Ethernet as both a service to their end customers but also as a new infrastructure technology to eventually replace their SONET/SDH networks. We’ve added more and more Ethernet functionality to our existing product line and are developing new products focused on the Ethernet market. We just announced an acquisition of World Wide Packets (News - Alert), which is one of the leaders in the Carrier Ethernet space. So we’re really focused on this segment and see a lot of growth and opportunities.”

“There’s been a lot of talk about Ethernet as a business service to replace traditional private lines, frame relay and VPN,” says Parks. “We’re into that. There’s also a movement for Ethernet as the ‘infrastructure’ for these new residential services. It’s a much lower-cost, higher bandwidth solution for residential triple-play services, for example, especially when you look at how much more bandwidth people need for Internet access and new video services, both broadcast, on-demand, IPTV (News - Alert) and all of that. Another emerging application is Radio Access Network [RAN] transport, a wireless backhaul application that’s normally TDM-based, such as a leased T1 or E1 from the incumbent provider. Your handset is wireless to the cell tower but then from the base station everything is wireline with the exception of some point-to-point microwave links. As mobile operators move from 2G voice-centric services to 3G data-centric services, and then 4G WiMAX (News - Alert)-type services, those handsets will be consuming a lot more bandwidth. In this environment, Ethernet has emerged as a really nice technology to get that traffic from the cell site back to the network operator’s mobile switching center. That part of the network is called the RAN, and it presents some technological challenges that are being overcome but it has taken some time to work through some of them. Those challenges center on timing and synchronization issues regarding voice traffic. Fortunately, there are a number of standards being developed by the ITU and IEEE (News - Alert), such as Synchronous Ethernet, to deal with this.”

“Another challenge that Ethernet is overcoming is how one can troubleshoot and monitor the network,” says Parks. “There are a number of standards being developed by the IEEE to handle various OAM [Operation, Administration and Maintenance] issues, specifically those involving Ethernet in the ‘last mile’. Ethernet is a technology that’s evolved from the LAN to the MAN to the WAN, and so we’ve had to augment it to make it carrier grade.”

“We’ve put together a portfolio that addresses all of the applications I’ve mentioned that’s very flexible,” says Parks. “It’s a solution that basically starts from the customer premises, or what we like to call the service delivery location, where the service is delivered to the residential or business customer, or perhaps even another network operator. From there, the solution encompasses the access network where the traffic is aggregated, and of course we have aggregator solutions as well. And we have Ethernet transport solutions and Ethernet service edge and core solutions too. Our Ciena CN 3000 Ethernet Access Series are service delivery/customer premise devices. Then there’s our CN 4000 Series. We’ve just made a significant enhancement to the CN 4200, which is basically a metro transport platform, a Layer 0 or Layer 1 platform, which is very successful in the market. We’ve introduced a Layer 2 Ethernet switching and aggregation functionality on that system. Our customers can now just add a new blade to those systems to make them an Ethernet switch as well as a transport platform.”

“Finally, there’s our CN 5000 Series products, which can do high capacity Ethernet switching,” says Parks. “So we’ve taken a number of steps to add that Ethernet intelligence to those products and to obtain MEF [Metro Ethernet Forum (News - Alert)] certification. The MEF wants to ensure that Carrier Ethernet looks and feels similar from one vendor to another and from one service provider to another.”

Extreme Networking with Extreme Networks (News - Alert)

Extreme Networks designs, builds, and installs powerful yet open Ethernet infrastructure solutions for enterprises and service providers. Converged networks built with their equipment support voice, video and data, over a wired and wireless infrastructure.

Recently, Extreme Networks announced the general availability of its complete Provider Backbone Bridging – Traffic Engineering (PBB-TE) solution that spans from the edge of the network through the metro core. PBB-TE is a technique to transport Carrier Ethernet services, thus natively extending Ethernet services across a provider’s network rather than employing other technologies such as SONET/SDH or MPLS. Extreme Networks’ solution is comprised of new software and hardware, as well as a strategic relationship with control plane partner Soapstone Networks (News - Alert).

Peter Lunk, Director of Service Provider Marketing, says, “There’s been a lot of discussion concerning Provider Backbone Bridging – Traffic Engineering [PBB-TE] technology, so we’re excited about what we’ve put together from a solutions and product perspective. During 2007 there just about every major provider began to seriously contemplate deploying Ethernet services, and so we’re excited to have a product in the right place to take advantage of this shift. To do this we had to develop the proper software and a hardware platform that extends from the metro core out to the customer edge where you run the PBB-TE circuits. Because PBB-TE takes the control plane out of the standard Ethernet protocol, we still needed a way to establish connectivity throughout the network. For that you need an external control plane to handle that. So, keeping these things in mind, we decided to develop a solution. We discussed the project with providers and got a lot of feedback. We discovered that the providers have a significant investment in their existing MPLS core network. Providers at first didn’t understand where PBB-TE fit into the infrastructure, but they soon realized that it provided lower cost access from a metro perspective and it could still work with their MPLS core.”

BT (News - Alert) has a huge deployment going on right now,” says Lunk. “Not all providers will have deployments that big, so you need to have smaller scale hardware to be able to handle some of the lower density networks and smaller sites were you may not be bringing in as many business subscribers in the same location. So we realized the need to offer a variety of hardware density to successfully deploy a PBB-TE network.”

Testing the (Ethernet) Waters

Ixia (News - Alert) is a leading provider of performance test systems for IP-based infrastructure and services. Service providers, network and telephony system vendors, semiconductor manufacturers, governments, and enterprises use Ixia’s test systems to validate the functionality and reliability of complex IP networks, devices, and applications. Ixia’s test systems use various standard interfaces, including Ethernet, SONET, ATM, and wireless connectivity.

Mike Haugh, Ixia’s Senior Product Manager, says, “We’ve played in this space for a long time, and we’re a leader in Ethernet testing. We had the most 1 and 10 gigabit ports shipped last year of any test vendor, so we’ve certainly found a sweet spot in the marketplace. With Metro Ethernet and Carrier Ethernet in particular, the trend has been that service providers over the last seven years or so have invested heavily in their backbone networks, which are mostly IP and MPLS based. Over the last two years, service providers have been evaluating and deploying new technologies and spending money upgrading their medium-haul or metro networks. A number of drivers are behind this, but primarily it’s similar to what was going on in the core in that they have legacy technologies there that are becoming more expensive to upgrade, as in the case of, for example, SONET infrastructure. To keep building out and expanding SONET, the cost-per-port is much higher than going with a technology such as Ethernet.”

“In terms of getting out totally new, flexible and higher-speed services, Ethernet has proven to be the most cost-effective transport mechanism, so there’s definitely an expansion of Ethernet into the metro and medium-haul networks,” says Haugh. “Now, aside from Ethernet as just a Layer 2 transport, there are still challenges around deploying Ethernet as a service. The Metro Ethernet Forum [MEF] is really leading in this area in terms of defining what those services are, such as the Ethernet Line Service [E-Line], a point-to-point service, and E-LAN multipoint-to-multipoint services, and the options that should be provided with those types of services. Where the technical challenges lie is what specific technologies are used in the cloud. It’s pretty clear, especially from the MEF’s definition, of what is delivered from one customer edge to another customer edge, but then in the middle there’s the cloud. And that’s really where the service providers are facing some challenges.”

Haugh drills down: “The primary question is, do they extend MPLS into the metro and medium-haul network, or do they use or leverage another technology? Really, the main competitor to peer MPLS in the metro is using peer Layer 2 Ethernet services. Some examples are using Q-in-Q, MAC-in-MAC, and the emerging Provider Backbone Transport or PBT, which is becoming a standard under the IEEE as PBB-TE.”

“Ixia participates in the MEF,” says Haugh. “Each specification we monitor closely and when a new specification is developed, such as MEF9, MEF14 and now MEF19, we’re on those specifications and we typically provide a conformance/performance test suite to test specifically to the MEF specification, though many of our customers want to go well beyond what the MEF is specifying. But definitely the MEF drives our activities. And when it comes to technology, there has been a surge of Layer 2 test requirements for peer Ethernet involving the testing of Q-in-Q and MAC-in-MAC, and the pre-standard implementation of PBT as well as the standard implementation of PBT-TE. Ixia’s other major effort is in fault management technologies, such as Ethernet OAM. The three main ‘flavors’ of that are the IEEE 802.3ah for point-to-point and last mile, and 802.1ag and y.1731 for fault management end-to-end over Ethernet service.”

Intelligent Choices

Sycamore Networks (News - Alert) makes intelligent networking products such as multiservice cross-connects, multiservice access platforms, access gateways, optical switching platforms, and element/network management and design software for major fixed line and mobile networks.

Sycamore’s Director of Marketing, Bob Travis, says, “We’ve actually had Gigabit and 10 Gigabit Ethernet service interfaces in our optical switches for about four years now. We had some customers in the Asia-Pacific region that were embarking on offering Ethernet services and they were converging their networks early on over there. Obviously, there was a lot of infrastructure technology begin implemented, and MPLS was happening from an IP service layer. These customers were looking for alternatives of how they could take and aggregate that to Layer 1. So we introduced 1Gbps and 10 Gbps service interfaces on our SN 3000, an optical edge switch, and then we really focused on the SN 16000, our core switch. So we’ve had Ethernet services capability for quite some time.”

“To fast forward from that time,” says Travis, “We see such advances as the packet optical phenomenon and different converged transport systems that are offering a plethora of multiservices. We entered that market back in the fall of 2007 with our introduction of a packet optical switching system called the SN 9000. The traditional TDM interfaces such as a T1s and DS3s are still out there and aren’t going away, and we found that we needed to offer a product that really supported a diversity of service interfaces and provide a system for network in transition that can do high density T1, E1, DS3, Gigabit and 10 Gigabit Ethernet, and optical services driven off of the same platform. That’s where we are.”

“Our biggest focus and value set is in a number of key areas,” says Travis. “For example, there’s interoperability. Ethernet has moved from the enterprise, gaining some functionality to run in a carrier class environment, but when you enter a carrier-class model, you must have compatibility and interoperability. We participate in the OIF (News - Alert) [Optical Interconnect Forum], which started a major initiative back in the fall of 2007 and held an interoperability demonstration for on-demand Ethernet services. We all hear about Ethernet flexibility, but actually trying to achieve it in a real network with multiple vendors being provisioned by a management system could get quite ‘interesting’. So the OIF’s event focused on testing and interoperability. For example, carriers are starting to leverage Ethernet as an extension to private line service, so they tested and demonstrated that. They demonstrated how we could go beyond manual provisioning methods and move into a more automated discovery capability. They also demonstrated how you can throttle Ethernet bandwidth, which they call ‘non disruptive bandwidth modification’. If an event trigger such as a video session occurs, how can you quickly, between multiple vendors and through an operational management system, actually increase bandwidth, taking advantage of Ethernet’s flexibility? That was demonstrated.”

“The two main standards used are UNI [User Network Interface] and ENNI [External Network-to-Network Interface],” says Travis. “The UNI is used when a client device connects to a switch-type device. The ENNI, also called the NNI, is used if two larger switch or transport devices connect to each other. The interconnect communication between one of our optical boxes and a competitor’s would be done via an ENNI. It provides some communications of the control plane through the system and it provides some interconnectivity.”

“With the influx of Ethernet services, there’s an interest in how you can adapt flexible optical services based on network resiliency,” says Travis. “Service providers can provide what I call ‘peered levels’ of services for network and service resiliency. By that I mean they will have the ability to offer different quality levels of service at different pricing levels, such a best-effort service or they could use existing SONET/SDH 1+1 protection services. Or they could use a nationwide mesh network, in which case they can offer some pretty dynamic offerings for tiered services for resiliency. They could offer different dynamic path restoration, a diverse conduit path or different conduit paths. This is useful because if your normal and emergency fiber paths through the network run to the same conduit that fails, the service stops anyway. But we have the ability to embed in all the nodes conduit IDs, which are attached to different circuits and you can examine those to ensure that you truly have diversely routed paths, so if there’s a fiber cut or failure in a circuit or a path, then the traffic will automatically take a separate path.”

“We’re also involved in operational excellence and efficiencies,” says Travis. “Carriers offer more capacity and services and need more efficient ways to turn up, monitor and reconfigure services more effectively and using fewer technicians. This is especially true of Ethernet services, because they are more dynamic than the traditional services. People talk about how Ethernet is striving for better OAMP [Operations, Administration, Maintenance, and Provisioning] services. We’ve put a great focus on developing those. For example, we offer CNM [Customer Network Management] and we have a feature extension whereby a carrier can extend some secure network visibility and have a partitioned view so that the customer can actually see the service that they’re running. Part of that is extending a bandwidth scheduling tool which is used for on-demand bandwidth modification. We provide that too.”

“Ethernet is everywhere and it’s becoming more dominant,” says Travis. “We also see things happening in the larger enterprise networks, such as the financials and global or nationwide networks where they’re actually starting to install private networks. This has been going on for quite some time. Some people outsource their network, and then a new management team may decide to bring it back in house. We’re seeing private networks being built within different cities, states and government agencies. They are obviously looking at the interconnectivity and the value set that Ethernet and optical mesh bring together.”


Carrier Ethernet: Extending Control to the Customer Edge

By Rebecca Rachmany

Metro Ethernet has been going through some important changes such as Provider Backbone Transport (PBT), a group of enhancements to Ethernet defined in the IEEE’s Provider Backbone Bridging Traffic Engineering (PBB-TE) spec that separates the Ethernet Service Layer and Network Layers, therefore enabling development of carrier-grade public Ethernet services.

PBT has begun to take hold in the industry. The main arguments for PBT are based on lower cost, revolving around the technology’s simplicity and capabilities for management of large-scale system. It is logical that most incumbents with large MPLS deployments are going to stay with MPLS cores. However, even the large router companies have admitted that PBT is going to provide the scalability on the edge, even in some MPLS networks. Furthermore, the complexity of converged networks is increasing as we see more mergers and new providers within the industry.

Much of the debate on this issue is conducted with the major vendors taking one side or another. Predictably, the vendors with large interests in routers and traditional Ethernet, such as Alcatel, Cisco, and Juniper, are consistently plugging MPLS and VPLS as the solutions of the future. Smaller vendors and those without router interests, such as Nortel, Siemens (News - Alert) and Corrigent, are reliably pushing for PBT solutions.

Certainly, within the PBT realm, there are a great number of new technologies ranging from the silicon all the way out to the network management systems. The wide variety of activity in the PBT area makes it look like an exciting industry. At the same time, the past suggests that making transitions to new network solutions takes an extremely long time, and the existing networks have a very strong foothold.

The Metro Ethernet Forum (MEF) is constantly debating this question, and establishing standards for how the services will be deployed. Within this debate, interoperability and OAM (Operations, Administration and Management) are the hot topics. Reliability and robustness are the top priorities when it comes to interoperability within the converged networks.

Despite the hot debate, eventually the vendors will need to admit that it’s not about taking sides: it’s about choosing the appropriate technology dependent on the specific operator’s needs in the specific areas of the network. In other words, for the foreseeable future, MPLS and PBT will co-exist in a variety of converged networks.

Even the largest companies with deployments of MPLS have admitted that the management is complex. However, they are already heavily invested in MPLS and VPLS solutions. AT&T, for example, has already developed sophisticated management solutions on top of the MPLS network, and it simply does not make sense for them to move to a PBT system at this time. Furthermore, due to the nature of their customers, they’ve found that sophisticated VPLS solutions are required only in a small percentage — fewer than 5 percent — of deployments. Within that specific business model, provisioning for large multinationals, the current system is working well for them.

Other telcos have taken alternative approaches. ntl, for example, is agnostic to the management capabilities, arguing for simply over-provisioning. Because of their wide reach, targeting of small customers, and the fact that they provision primarily data customers, this approach means that they aren’t even focused on the underlying solution. The approach of over-provisioning isn’t a popular one with major telcos, but it is a unique approach that allows ntl to focus on Applications at Level 7 needs rather than control on the Layer 2 and Layer 3 level.

Certainly the core networks are going to stay MPLS based for the medium to long term. However, by and large, the argument for PBT seems to be dominating the edge deployments for Metro Ethernet in the industry. Because of PBT’s deterministic approach, management of nodes becomes straightforward. Traffic shaping, granular provisioning, and fault identification are all built into the system. Furthermore, the intrinsic structure of the MAC-in-MAC addressing scheme mean that it is straightforward to create additional nodes and sub-nodes, further scaling the network.

When discussing the lowered costs of PBT, it’s important to note the source of these lowered costs. The main points are in the area of management and fault detection. Firstly, regarding management, PBT provides a centralized control plane, allowing centralized management. Furthermore, PBT’s addressing scheme means that it is easier to add nodes to the network within that management system.

This quickly translates into easier management, and less required training for staff. The major operators using MPLS have developed proprietary in-house management solutions. Obviously, such solutions are very expensive to develop, maintain, and train staff to use.

A further cost savings is achieved when it comes to fault management. Identifying a fault requires that the network can see each node, and each Virtual Local Area Network (VLAN), and measure exactly what is going on at each point. A multitude of approaches are offered for fault management, but currently PBT is offering an elegant solution for granular identification of traffic behavior.

Another financial incentive for PBT is the ability to provide differentiated services and Service Level Agreements (SLA). Once an operator establishes a VLAN, the service quality can be guaranteed across that VLAN. This is not useful just for singling out specific customers, but even looking at different types of traffic within a particular customer’s network. For example, a brokerage firm may have all of its trade data to be mission-critical, needing a different level of priority than its email or even video data. Therefore, a highly granular level of QoS management actually allows operators to sell differentiated services. This kind of tiered service increases income opportunities for service providers.

The next natural step for PBT is further extension out to the edge. Currently, when vendors talk about PBT to the edge, they are referring to the network edge, that is, the first aggregation point. However, PBT can naturally have applications further out, at the actual customer premises. For example, at a campus or multi-tenant building, PBT can be used to provision each office separately, or again, to provision separate services within the office.

Until now, lack of PBT to the edge limited the level of service that could be provided to individual customers. Furthermore, if an individual customer office was not getting sufficient service, it is difficult and expensive to identify the location of the traffic delay. Operators can only see at the level that is provisioned at this level, meaning that there are a limited number of available VLANs. When considering the needs for differentiated services among various customers, and the rising customer demand for Ethernet services, it’s clear that the number of VLANs will reach its limit relatively quickly.

Within this context, a customer-edge device with built-in PBT capabilities makes sense. Today’s advanced silicon solutions are allowing the building of cost-effective Customer Premises Equipment (CPE) with PBT as part of the basic feature set. Such CPE equipment can be provided in 1U or even smaller form factors, so that it can easily be integrated into the customer’s data center. Currently, the CPE vendors have gone with much more simplified solutions, and are using various management overlays and probes in order to address the solution. However, the CPEs including PBT are already priced similarly to the other customer equipment devices. Having gained equal footing on this point, this approach presents a far more elegant and practical solution than the management overlays, probes, and other solutions so far proposed.

Bringing PBT to the customer edge exponentially increases the number of VLANs that can be provided at multi-tenant sites, as well as at base stations and other types of end-user premises. Once the operator provides such an extensive solution, routing, fault management, and provisioning become much more cost-effective.

Operators can measure exactly what each individual customer is getting, and charge for guaranteed SLAs accordingly. This provides increased sources of income, and a higher level of customer satisfaction.

Fault management on a granular level is also critical, because of the high costs of servicing the edge. Without granular levels of management, operators can find themselves needing to send out support personnel to the edge in order to identify the source of the fault. If the fault is indeed at the edge, this makes sense, but if the fault is actually with the customer’s equipment, or in the core, the deployment of personnel ends up being a huge cost. Operators welcome any solution that can help reduce this major cost.

Currently, the CPE vendors have gone with much more simplified solutions, and are using various management overlays and probes in order to address the solution. As the CPEs including PBT are priced similarly to the other customer equipment devices, the provides a much more elegant solution than management overlays, probes, or any other type of solution meant for addressing this problem.

The exciting point about extending PBT to the edge is that its impact throughout the industry is a lot broader. As operators are able to differentiate themselves with guaranteed QoS and reliable management for sensitive voice and video traffic, mission-critical data, and even the ability to serve as a backbone for delay-sensitive TDM access networks, it will be interesting to see how the Carrier Ethernet players as a whole will adapt and expand their role in the market.

Rebecca Rachmany is Director of Marketing for Telrad (News - Alert) Networks, a company that has been developing carrier-grade communications equipment for more than half a century. Telrad provides development capabilities that focus on integration of core technologies into standardized, Tier-1 carrier-class products. For more information, visit


Teaching Old Copper New Tricks

Hatteras Networks (News - Alert) develops equipment enabling carriers and service providers to deliver high-bandwidth reliable business services to business locations not served by fiber. This is driven by the very large bandwidth and services gap that currently exists between a traditional T1/E1 service and next-generation fiber-based services. Hatteras Networks delivers broadband Ethernet solutions over existing copper facilities to enable service providers to deliver transparent Metro Ethernet services and address the growing demand for high bandwidth mobile wireless and DSLAM backhaul transport.

Hatteras Vice President of Marketing and Product Lifecycle Management, Gary Bolton, says, “Every service provider is trying to significantly reduce their network and OpEx costs, and are attempting to deliver more advanced services. Data has long dominated service traffic on any network. The TDM-centric world of the past has given way to IP and VoIP. Ethernet has been around for 30 years, and it continues to evolve. In the past, we always awaited the ‘next big thing’. Ethernet continues to be ‘what’s next’. It’s the only service I’m aware of that’s fully ubiquitous worldwide. You can plug in an RJ-45 connector anywhere in the world. That significantly reduces costs and eases management. When people think of metro Ethernet they think optical transport. It has high bandwidth and resiliency. However, only 15 percent of businesses in the U.S. and only 9 percent in Europe have access to fiber facilities. As businesses move to converged services, they need more bandwidth and transparent LAN services and multi-site connectivity, but they don’t have fiber everywhere. That’s where we come in.”

“Hatteras is able to deliver a full Ethernet service set over existing copper wire facilities,” says Bolton. “This gives carriers a wide-ranging Ethernet offering. They can deliver Ethernet services to the big new buildings over fiber, and to the other 85 percent of the locations over existing copper. They can have the same SLAs [Service Level Agreements] and high bandwidth. It’s a great opportunity.” IT

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


The following companies were mentioned in this article:

ANDA Networks (

Ciena Networks (

Extreme Networks (

Hatteras Networks (

Ixia (

Matisse Networks (

Metro Ethernet Forum (

Sycamore Networks (


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