Blueprint: Metro Ethernet


	Now is a Great Time for Metro Ethernet!
Now is a great time for metro Ethernet. With continued and growing industry support, the technology has clearly moved beyond its origins in local area networks to become a compelling, robust solution for meeting the service delivery and cost reduction requirements of today's leading carriers and service providers.

	Ethernet – Carrier Challenges and Opportunities
It is clear that in the future cars will fly and voice, data and video will be carried on converged packet networks. Good opening line, huh? Seriously, the problem we always face with emerging technology is how to migrate the contemporary infrastructure into the emerging networking architecture. This article will deal with the challenge that Ethernet faces as it becomes the predominant bearer layer for converged metro and regional networks. It should be first noted that Ethernet was designed for a completely different application. The original application space for Ethernet was to support low cost enterprise networking. Today, Ethernet has become so prolific in the enterprise space, that it is pretty much synonymous with local area networking. The challenge is how to adapt the technology to the rigors of carrier metropolitan networks. Read on!<br><br> <p class="normal" align="center"><font face="Arial" size="2" color="#1A1872"><img src="http://www.convergedigest.com/blueprint/ttp05/images/articles/z1alcatelmef-fig3.gif" border="0" width="400" height="264"></font></p>

	Integration of MPLS with Optical Transport Networks
Traditional metro optical networks were designed to carry fixed-rate telephony and private line traffic in a reliable and resilient manner. Over the last decade, service providers have experienced tremendous growth in data services with the aggregate demand for data traffic now exceeding circuit-oriented traffic. The metro optical network is evolving to meet this need. A multiservice ADM and its close interworking with an IP/MPLS core helps to offer a robust solution to deploy a fully data-aware transport solution to next-generation transport networks.

	Optical Ethernet Drives Convergence in Triple Play Networks
Gigabit Ethernet is now the standard interface for commercial customer LAN switches and routers, video EdgeQAMs, cable modem termination systems (CMTS), and application servers of all types. It follows that using GbE as the metropolitan area networking (MAN) technology would then lower the cost and complexity of connecting headends and distribution hubs as well as fiber-fed commercial sites. While GbE is the predominant interface on the endpoints that need to be connected, the question remains as to what platform is best suited to transport traffic between sites. SONET or Gigabit Ethernet?

	Ethernet over SONET/SDH -- The Best of Both Worlds
SONET/SDH and Ethernet are the leading technologies in their respective markets. Both benefit from scale economies and positive market externalities. Most important, SONET/SDH and Ethernet are complementary, and combining them creates a whole that is greater than the sum of the parts. The features of Layer 2+ switches within the metro Ethernet network may be expected to evolve over several years. This article discusses the advantages of Ethernet over SONET/SDH technology for delivery of broadband services.

	Collapsing the Network Layers with Metro Ethernet
Traditionally, service providers have preferred a layered topology for their networks, relying on an access layer, an edge aggregation layer and a core aggregation layer. By leveraging high density Ethernet switches and routers that have robust resiliency features to guarantee availability, service providers can collapse the traditional multi-layer network topology, while differentiating their offerings to wield a competitive advantage in the marketplace.

	Finally…Ethernet Service Delivered Over An Optical Metro …By The Way, Can I Also Get A Couple Of T1s?
Ethernet was invented over 30 years ago and it has long dominated the customer premise. Why has it taken so long to get Ethernet in metro networks? Where does the industry go from here?

	Building Large Metro Ethernets Requires MPLS
With continuous technology advances, service providers and end users are turning to Ethernet to enable a wide variety of next generation services. Whereas bridging has traditionally been used to extend Ethernet networks, carrier-grade networks will need to use MPLS for large-scale MPLS deployments.

	Ethernet Stands in the Gap
With all of the obvious benefits of Ethernet, one might question what's been holding the technology back and keeping it from enjoying greater popularity among enterprises and service providers. Service providers, ever conscious of costs, are concerned because of two primary design shortcomings that hamper Ethernet. The first problem is that Ethernet does not offer well-defined hand-off specifications and demarcation points. Secondly, Ethernet provides very limited parameters for performance monitoring and fault isolation. Without these capabilities, Ethernet services are “blind services” that are prone to high opex costs and cannot compare in reliability with frame relay and private line services.

	Metro Ethernet Evolves for Carriers and Customers
Ethernet, when used in conjunction with MPLS, is the first technology at the metro business and consumer edge that meets all of these sometimes-conflicting demands. Given its ubiquity at the desktop, Ethernet provides a natural convergence layer for a variety of higher-layer protocols and applications. These include IP and other Layer 3 protocols, supporting data, voice, and video traffic. For new buildouts, customers and carriers must no longer suffer operationally and cost-intensive handoffs between Ethernet, Frame Relay, ATM, and SONET/SDH.

	Extending the Benefits of Metro Ethernet with Copper
A serious last-mile bottleneck exists that is denying the reach of Ethernet networks to a very large number of potential customers who are not served by fiber. For the vast majority of both Small and Medium Enterprises, fiber access has not kept pace with the growing bandwidth needs. In July 2004, the IEEE 802.3ah Ethernet in the First Mile standard was ratified. Here's an update on what these standards mean for the industry.

	Migrating Enterprise Clients to Ethernet-based Services
Some of the vertical markets currently leading the demand for Ethernet services include schools/universities, government organizations, financial storage networks, high technology centers, and wholesale telecommunications operators. Growth markets for Ethernet services include manufacturing, healthcare, small and medium enterprises (SMEs), DSL backhaul, and residential services. While they can certainly win new customers with a broad range of Ethernet service offerings, carriers should first look to their existing customers as migration candidates.<br> <p class="normal" align="center"><img src="http://www.convergedigest.com/blueprint/ttp05/images/articles/atrica-fig2.gif" border="0" width="350" height="274"></p><br><br>

	Survival of the Fittest – A Contrarian’s View
Will the industry continue to move toward Cogent's data only network model or will a converged network infrastructure prevail? Dave Schaeffer, Cogent's CEO, argues that Internet service is a commodity, whether the industry realizes it or not. The commodity product that we all manage is the cost to take one bit of data and transfer it one mile.

	Scaling Ethernet: QoS and Resiliency for the Metro
The mass rollout of Ethernet infrastructure has been predicted for some time, fueled by the promise of triple play, IP-video delivery, VoIP and other services adding to the service provider's revenue base. However, current service delivery for Ethernet at the edge won't cut it for a variety of reasons, including problems with scale, QoS and resilience. VPLS/MPLS, which is ideal for the core of the network, is costly and complex to extend to the customer premise, as the technology cannot easily handle video broadcasts, consists of an unwieldy point-to-point architecture and is costly to operate for the carrier when used in this way. Solving these scalability and manageability issues is now the focus of a new IEEE project approved in late 2004 known as 802.1ah. The new project, officially titled “Provider Backbone Bridges” will define an architecture and bridge protocols allowing interconnection of multiple VLAN-based networks to scale to over 1 million service connections. <br><br> As providers look to put an increasing number of services over an Ethernet infrastructure, addressing the scalability and manageability challenges will be key. The IEEE 802.1ah study group is a move in this direction and many vendors are now supporting this study group, which will meet again in March 2005 to move the standard process forward.

	VPLS Enables Ethernet Everywhere
The widespread adoption of MPLS in provider networks since the late 1990s has enabled many network benefits, such as traffic engineering, consolidation of multiple networks to a single IP/MPLS infrastructure, operationally efficient VPN services, increased resiliency, and better control of QoS parameters. In the coming years, VPN backbones of service providers may grow to immense sizes. This challenge requires requires an approach to service architecture that emphasizes scalability while preserving simplicity and resiliency. This is where VPLS enters the picture. VPLS delivers a multipoint-to-multipoint Ethernet service that can span multiple metro areas, and that provides connectivity between sites as if they were attached to the same Ethernet LAN.

	Metro Ethernet Will Require New OAM Tools
The advent of Ethernet as a Metropolitan and Wide-Area Networking technology has driven the need for a new set of Operations, Administration and Maintenance (OAM) protocols. Service provider networks are large and complex with a wide user-base, and they often involve different operators that must work together in order to provide end-to-end services to enterprise customers. Enterprises have managed Ethernet LANs primarily with protocols such as SNMP, ICMP echo (or IP Ping), and IP Traceroute. However, Ethernet in the service provider space is an entirely different ballgame.

	Equipping Metro Optical Networks to Deliver Ethernet Services
To address the needs of the various Ethernet-based applications, service providers have to create a set of service descriptions to enable the transport of Ethernet data from the enterprise network through the Metro Area Network. The Ethernet service descriptions can be divided into two categories: 1) Leased Line or 2) Switched services. The level of transparency and the bandwidth allocation method differentiates the two service categories. The metro IP/Ethernet layer network needs to be able to provide a switched Ethernet and/or routed IP network.<br> <p class="normal" align="center"><font face="Arial" size="2" color="#1A1872"><br> <img src="http://www.convergedigest.com/blueprint/ttp05/images/articles/2005meriton5.gif" border="0" width="195" height="181"><br> <br> <b><i>Network protocols in an Ethernet Services Capable Metro Network</i></b></font></p>

	The Secret to Ethernet Success: Older Technologies Must Play Nicely with New Ones
Many enterprises are now sold on the benefits of Ethernet access for their WANs. Yet they also know they are well-served by investments in heterogeneous legacy infrastructure and services with proven reliability, quality and flexibility. From the enterprise point of view, it is the service provider's task to leverage existing network resources while opening a path to high-quality, lower-cost Ethernet services. Enterprises may give up some “nice to haves” to take advantage of new services, but there are two requirements they will not sacrifice, regardless of savings: (1) The ability of all of their office locations to communicate seamlessly with one another, and (2) the guaranteed QoS they enjoy from legacy ATM, Frame Relay and TDM.

	Equipping Metro Optical Networks to Deliver Ethernet Services
Ethernet services represent a significant growth opportunity for service providers and a potentially significant productivity gain for customers. Both parties are looking to Ethernet to meet the growing demand for higher bandwidth, lower operational expenses and better management and control. To understand Ethernet services and revenues, you need to know the current positioning and where the market is headed. Like any new service offering Ethernet services are subject to a "life cycle" of technology and implementation.

	WAN Optimization: Finding the Best Approach
There are critical factors beyond bandwidth limitations that impede performance and productivity. While users complain that the network is painfully slow, network managers insist that the problem must lie outside the network, since utilization is at only a fraction of the total bandwidth available. How can both arguments be correct? Latency is the secret throughput killer. Physics dictate that latency is unavoidable in a wide area network - the information takes some small amount of time to traverse the network connection. But when transport and application protocols are layered on top of typical network latencies, frustration can mount as employees wait for data and applications to load.

	Switching, Multiplexing & QoS in Metro Networks: How Do They Affect Services?
Does the domination of the Ethernet protocol mean that telecommunications providers should adopt Ethernet switches for their networks, as replacements for their traditional SONET/SDH elements? Since some of the key offerings driving broadband network investment today are isochronous services like voice, IPTV and broadcast video it is worth investigating how differences in the two primary L2 Media Access Controllers, Ethernet (IEEE 802.3) and RPR (IEEE 802.17), affect these services

	Enabling Mass-Market Deployment of Ethernet Services – Profitably!
The complexities of delivering WAN-based Ethernet services have traditionally been concentrated in the access network, typically accounting for 80 percent of a carrier's capital and operational costs. The underlying problem is that the existing access infrastructures come from different legacy roots. Carriers need an improved model of access infrastructure, one that is purpose-built for managed Ethernet service delivery.

	Using Pseudo-Wires for Mobile Wireless Backhaul over Carrier Ethernet
The continued evolution of mobile wireless services is toward technologies that are intrinsically packet-oriented, such as HSDPA and HSUPA, and indicative that packet access networks, rather than TDM-based T1s and E1s, are the logical transport for backhaul in the RAN. A number of new technologies that are cost-effective and provide flexible, high-capacity backhaul transport are emerging as the frontrunners for next-generation packet access networks. These new technologies include Carrier Ethernet (also known as Metro Ethernet or Optical Ethernet), xDSL, cable HFC, EPON/GPON, and broadband packet radio (including WiMAX. Pseudo-Wire solutions not only enables mobile wireless operators to use new packet access networks, it also gives operators a choice among multiple packet network technologies in the RAN, including Carrier Ethernet, xDSL, cable HFC, and even broadband packet radio.)

	Whither T1? Mid-Band Ethernet Delivers 2-Mbps to 45-Mbps over Bonded Copper
Mid-Band Ethernet supports native Ethernet at rates from 2 Mbps to 45 Mbps over bonded copper pairs. Copper bonding also increases the increases the reach of Metro Ethernet service networks from about 12% of business sites to well over 95% of business sites. Will T1 go the way of the horse and buggy?

	Sustaining the Ethernet Ecosystem: The Need for 100 Gigabit Ethernet
Ethernet's ubiquity and this inexorable demand for bandwidth are pushing the industry towards the next generation of Ethernet technology -- 100 Gigabit Ethernet. Vendors currently involved in developing the next generation of Ethernet anticipate it will be 2010 to 2012 before 100 GbE products are ready to ship. Here's the business case.

	Metro battle: MPLS vs. Ethernet
MPLS has won the battle within core networks and has become the dominant internetworking technology. Some argued that MPLS should be extended to the network edge. Ethernet, the most successful networking technology ever developed, has won in the enterprise environment and is being extended to the metro. Will this success limit MPLS to the network core?

	Premium IP-VPNs: Opportunity Knocks
The winds of change are getting stronger as enterprises increase their use of multimedia, always-on applications – changing the IP VPN landscape. Now is the time for service providers to roll out Premium VPNs supporting non-stop routing and offering guaranteed QoS levels for different application types.

	Illicit Fiber Tapping of Ethernet WANs and the Advantages of Layer 2 Encryption
While it runs counter to conventional wisdom, fiber can be tapped — even without breaking cable sheathing. When used illicitly, optical taps can provide unfettered access to data and voice communications passing over a fiber line. Implementing encryption at Layer 2 ensures security of the fiber optic transmission and makes the data virtually impossible to misappropriate by those with malicious intentions.

	Capitalizing on the Evolution of Metro Nets: Understanding Multidimensional Ethernet
For years, Ethernet supporters have predicted that Ethernet will become the dominant network technology and lead to a truly homogeneous network. Even as new standards have threatened to provide functionality beyond the scope of Ethernet, relentless innovation has led to the evolution of an Ethernet that can provide unparalleled scalability, reliability and Quality of Service (QoS) for next-generation Metro networks. The result, Multidimensional Ethernet, is a combination of MAC-in-MAC, Hierarchical QoS, Ethernet Cross-Connect, and Service Resiliency technologies that maintain Ethernet's ability to meet the specific functional needs of the rapidly growing business services market.

	Building Next Gen Modular Communication Platforms with AdvancedTCA
There is a fundamental change occurring in telecommunication platform designs that have been ushered in by development of open standards, modularity and an effort to reduce cost through an interoperable, plug and play kind of economics. This article provides an overview of some of the key changes in telecom platform designs and the effect these changes have on the industry.

	Gigabit Monitoring -- Interop's SpyNet Enables Virtualization of Monitoring Tools
Interop is a significant event for network engineers, in part because InteropNet is known as the state-of-the-art network for demonstrating new technology . To ensure that such business activities can take place, there is a secondary overlay network that is also built along with InteropNet -- SpyNet, which enables the total traffic aggregated from multiple switches or taps to be redistributed to a parallel array of collaborating monitoring tools.

	Gigabit Monitoring – How-to Segregate and Load-Balance 10-Gig Traffic among 1-Gig Tools
2007 will emerge as the year of 10 Gigabit. Yet one challenge remains. How to monitor mission-critical traffic at full line-rate in order to ensure network integrity, including performance, security and compliance. 10-Gig monitoring tools are not readily available and are like to be costly. A new breed of Data Access Switch is an alternative.

	Gigabit Monitoring -- Tap Aggregation, Regeneration and Filtering to enable Deep Packet Inspection (DPI) in Carrier IP Networks
The weapon of choice for service-oriented network monitoring is Deep Packet Inspection (DPI), enabling providers to identify, classify or even selectively block IP traffic. For the technology to work, DPI must be able to unobtrusively acquire high-fidelity replica of production traffic from multiple sources across a triple redundant network. Recently, instead of using conventional network taps, the Data Access Network (DAN) has emerged as the “Best Practice” data access and network monitoring architecture for cost-effective DPI monitoring/

	Carrier Ethernet Ready for Prime Time: Five Things to Consider
Recent announcements concerning carrier plans to deploy Ethernet in metro and core networks clearly indicate that Ethernet's familiar role in the enterprise LAN has evolved to encompass MAN and WAN applications. Today, virtually every office environment and many residences count on Ethernet networks to interconnect individual workstations and peripherals. What follows are five things to keep in mind as you consider a larger role for Ethernet in your network.

	Architectural Choices for Ethernet/Optical Transport Convergence
Network operators face a multitude of choices in creating a converged Ethernet-Optical transport network. Here we examine three such options: IP-over-DWDM, Carrier Ethernet Overlay, and Carrier Ethernet Transport.

	Ethernet VPLS: An Alternative to IP MPLS for Post-Frame Relay Communications
As applications continue to push the limits of networking, it is clear that legacy networks such as Frame Relay and ATM will not scale to support enterprise demands. To date, IP MPLS services have been the only viable alternative for medium to large-size enterprises. While IP MPLS addresses the need for any-to-any connectivity and CoS, the service is difficult to implement and manage. With advances in networking technology, such as VPLS, CoS, and EAPS, Ethernet services have emerged as a compelling alternative to IP MPLS services.

	Network Evolution to 100 Gbps
As data demands increase exponentially, current 10 Gbps networking has become insufficient to meet tomorrow's networking needs and, while 40 Gbps is entering a growth phase, it is insufficient for many future network applications. Network infrastructure is preparing for the next leap… to 100G.

	Survivable Optical Networks: Intelligent Control Planes Enable Self-healing Networks
Recently, in a couple of incidents, undersea cable lines were cut or damaged by what appears to be dragged or discarded ship anchors. The adverse impact of interrupted transoceanic network traffic – often entailing significant financial consequnces – is prompting many network operators to move beyond pre-existing submarine cable network restoration plans. Control plane-based automation schemes are a key tool to enhance network survivability.

	A New Class of All-IP Routers; At Your Service
For video and mobile broadband upgrades, major carriers and service providers are deploying multi-service edge routers (MSERs). MSERs can best be thought of as a service control point that combines subscriber management, edge routing, and Ethernet aggregation over either ATM or Ethernet networks. Additional features such as network security, P2P traffic management, and session border controls for VoIP services, can be added as the MSER and the market demands for them.

	WiMAX: New Kid on the Block... And a Step to 4G
The newest WiMAX standard, 802.16e-2005 (Rev-e), not only supports mobility, it has as its heart OFDMA technology -- an air interface which has already been adopted as the basis of all next-generation, or 4G, wireless technologies. But it goes farther than just the air interface. 4G is expected to consist of OFDM-based radio networks -- boosted by advanced antenna technologies such as multiple input-multiple output (MIMO) and beam forming -- with flat-IP architectures that are packet switched, delivering an order of magnitude boost to end-user bitrates. Here's the pitch.

	Carrier Ethernet OAM -- Enabling Next-Gen Services over Metro Ethernet
Ethernet Operations, Administration and Maintenance (OAM) is a generic term for a broad set of terms and capabilities. Each Ethernet OAM tool has its own objective and as whole, they complement each other. The major functions are diagnostics and troubleshooting, including detecting and determining faults, collecting performance statistics, monitoring media health and detecting service performance. Using OAM tools, network operators can effectively monitor their network, detect and respond quickly to failures, and provide improved service to their customers.

	The True Cost Implications of a <br>Metro Network Architecture
Currently, network architectures are often based on IP routers with SONET/SDH MSTPs in every office, handling a traffic mix of TDM-based services including voice and low-to-high-speed private lines, as well as packet-based services such as Internet, IPTV, VoIP and IP-VPN and Carrier Ethernet. With the advent of hybrid packet-optical transport systems, new low-cost, scalable architectures are possible. In fact, many services that have traditionally been carried end-to-end through IP/MPLS networks can now be transported and switched through Ethernet/OTN-optimized packet optical networks.