Metro Ethernet as the Next- Generation Broadband Network

Transcription

1 Metro Ethernet as the Next- Generation Broadband Network Enterprise and service provider core networks typically have plenty of bandwidth the links between them however are comparatively slow. In the metro, IP edge, and the IP access networks, bandwidth is in short supply. Metro-area networks have many of the same capacity issues and limitations on delivering high-performance connectivity and rich services. Despite rapid deployment of Gigabit Ethernet in the enterprise, traditional TDM underpinnings in metro networks limit their ability to support Ethernet connectivity, IP services, or enormous growth in data traffic. To achieve profitability, service providers require networks that are integrated with their legacy infrastructures and are flexible to respond to changing market conditions and diverse customer requirements. This is especially important in metropolitan area networks because of the critical interface between enterprise and service provider networks. Ethernet has emerged as the leading access medium for a variety of reasons: it enables most cost-effective services; it provides ample bandwidth between the enterprise and the metro; it eliminates access bottlenecks; and allows service providers to deliver multiple data, voice, and video services to enterprise and consumer customers over a high-speed access connection. This paper shows how to build scalable access for subscribers of all flavours: enterprise, SOHO and residential. Emphasis will be on metro networks with an outlook of large-scale data networks and IP-based services. Author Cisco Systems Johann.Strauss@cisco.com Figure 1 Metro fibre buyers 0% 80% % % 20 20% % Source:The Yankee Group Europe, Introduction Collocation, Hosting, Content and Distribution Storage Metro and Gigabit Ethernet Providers Mobile Operators Corporation, Government, Universities Second and Competitive Domestic Operators Pan-European Infrastructure and Service Providers Global Infrastructure and Service Providers There is no doubt that Ethernet transport is gaining momentum as the technology matures and new standards appear. With its ubiquity, speed and cost leadership, Ethernet has become the choice as a universal interface to the customer. Imagine the simplicity of a phone jack being applied to the delivery of next-generation data services. Today, customers must pass through several wide area network (WAN) technologies and services in their quest for more bandwidth. Each technology creates added equipment cost and administrative complexity. With Ethernet, Fast Ethernet (FE), Gigabit Ethernet (GE) and -Gigabit Ethernet (GE) in the distribution ring, aggregation layer and metro backbone, service provisioning and activation and bandwidth upgrades can occur quickly, without requiring additional hardware upgrades. The Yankee Group Europe, 2001, estimates, in the distribution of metro fibre buyers by segment shown in Figure 1, that 2% of the metro fibre buyers will be the metro Gigabit Ethernet providers. Now think dark fibre. The advantages of optical fibre include high bandwidth, long runs up to km, and the capability of being run in the same conduits as power and gas. For service providers considering new build-outs, fibre is the most logical choice. Gigabit Ethernet over optical fibre provides enough bandwidth to insure a very long life span for the network infrastructure; in particular, the optical fibre infrastructure may be amortised over long periods of time ranging from 20 or more years. Lighting dark fibre with Ethernet technology represents the feasible business case to launch innovative services and invest in a no-risk, future-proof solution. 99

2 Service providers offering Ethernet to the business (ETTB) generate revenue streams from providing raw bandwidth and connectivity services directly to customers. They can also get more revenue from sharing arrangements with other service providers that offer unique applications that require large amount of bandwidth, such as disaster recovery, security, storage area networks, broadcasters and video distribution companies. Ethernet/FE/GE/GE help in preparing the network for delivering of userconfigured, bandwidth adaptive, applications-aware networks. With the emergence of Gigabit Ethernet, the market for dark fibre is taking off thanks to service providers who have identified high-bandwidth users located in dense metro areas. New Metro Access Market Robust investments in optical technology have created massive capacity at the core. Today, Internet backbones are running in same cases at Gbit/s. The metro core supports gigabits of bandwidth. But the links between the subscriber and the metro run at sub-megabit or even kilobit per second rates. The access network still represents the bottleneck. The first mile is an important business opportunity because of the mismatch between current solutions and customer needs. Faced with exponential user increase, bandwidth killing content, customer dissatisfaction, service providers are looking at new solutions to increase the speed at which Internet users move from site to site and receive dynamic content. Only the end-users can fill the pipes, but they still have STRAW access and long waiting. ETTB is aimed to serve the TOP market and the small and medium business to deliver: e-commerce, e-business, e-health, e-content. Figure 2 Bandwidth gap Bandwidth Bandwidth Gap The target customers The objective of ETTB is to deliver data, voice, video over a simple and inexpensive Ethernet network. The unique aspect of this solution is the use of Ethernet mainly over fibre as a means to provide /0/ 00 Mbit/s access directly to business customers. The corporate customers that require these metro services range in size from the Fortune 00 Enterprise customers all the way down to medium and small commercial businesses located in commercial business parks or building complexes. Multiple branch locations in one metro area, high-bandwidth applications, such as distance learning, medical imaging, videoconferencing, CAD/CAM, storage and requiring the optimisation of IT staff and control of resources in the support are optimal environments to justify the adoption of GE in the enterprise market. The target customers are highlighted here per vertical market: business parks, hotels, business centres and companies with several sites; insurance company/banks; public clinics, ambulance service, hospitals, health care department; public sector organisations, government offices and agencies; schools, universities, college and libraries; and university and research centres. Accelerating the Business Service delivery value Fundamental value = More bandwidth to customer The fundamental value of the service proposition is more bandwidth to the customer. The main service is always-on MEGA Internet connectivity, at /0 Mbit/s, at competitive tariff in comparison to other fibre to the building solutions. Enterprise traffic will continue to increase 30 60% annually. As the number of PCs accessing the Internet continues to grow and the speeds at which they connect continues to increase, the demand for greater bandwidth in the enterprise local, metropolitan and wide area network (LAN, MAN, WAN) will continue to increase. /0/00 Mbit/s Ethernet is widely deployed in the enterprise and service provider market. Having the possibility to provision bandwidth from Mbit/s to 1 Gbit/s at incremental steps of 1 or Mbit/ s without involving hardware changes and consequently rapid provision is one of the reasons that makes Ethernet technology attractive. For LAN applications, GE is a natural evolution that will enable network managers to scale their networks from, 0 or 00 Mbit/s to 000 Mbit/s. Always on Always on is a new service option that enables services like digital real-time video streaming and video recording for telesurveillance and security in public and private spaces. Development and deployment of new applications and services that would not be possible with a dial service are now possible: think Internet connection in the schools or libraries and IP telephones on each teacher s or doctor s desk. The nature of Ethernet also allows upload of content, such as lessons in schools or seminar content. Ethernet as service provider access option Enterprises like the idea of using Ethernet access from their service provider to connect two main sites together, or to connect the main site to numerous branch offices. They are looking for a service with all the speed advantages of Ethernet on which they can run multi-protocol traffic, but still maintain the structured addressing scheme, network control, security and filtering, and management that they have on their networks today. Although Ethernet does not natively support quality of service (QoS), running IP on top of a metro Ethernet network becomes an attractive option, that can also address the need for network infrastructure that integrates voice, video, and data services over a single network. Enterprise Metro IP Edge IP Core Optical Transmission Core Offer single bill payment and provider for all media The initial primary driver for Ethernet over fibre by individual customers is the significant cost reduction of the local loop: tariffs for flexible bandwidth with better prices 0

3 than fixed leased lines are taking off also in Europe. All in one is the magic formula that allows the New World customer to go for a monthly fixed fee and predefined/controlled telecommunication expense throughout the year. Offer equal or better service quality of the overall service Ethernet offers a better service quality and a better customer satisfaction, reducing the initial time to activate the service and the time to introduce changes in the service (such as increase the bandwidth or connect a new branch office) and increasing the profitability of the employees. Technical enablers Fibre capacity exploitation in the metro area using DWDM The market for metropolitan dark fibre will grow strongly over the next five years due to a combination of factors. In most European cities, there are at least two dark fibre suppliers: one typically a utility company, the other a subsidiary of the various international ventures. Fibre is not supposed to suffer dramatic reduction of price in the metro area; by contrast, bandwidth will become cheaper and cheaper due to the introduction of dense wavelength division multiplexing (DWDM). The large amount of cheap bandwidth has already reduced the overbooking needs in the metro areas, enabled simultaneously best-effort services, like common Internet access and real-time services including video: the customer service experience has increased in satisfaction. All Gigabit Ethernet ports are full duplex and switched; so Gigabit Ethernet is no longer a shared domain, half-duplex technology. Non-disruptive first-mile fibre deployment Carriers are realising that they must fill in the missing broadband pieces in the metro and get physically closer to the target customer; the fibre pricing structures cannot be based simply on distance, but rather on buildings passed. To facilitate the deployment of fibre in the first 0 m, traditional technology such as poling, common to the cable modem market that use pole to home wiring, are available. But also new technology such as micro-tunnelling and directional drilling are today widely available; they minimise the impact on the environment and facilitate the relation with the community. Flexible across multimedia and distance Ethernet is supported at /0/00 Mbit/s on diverse media: CAT3 and CAT4, CAT and CATE, SMF and MMF, and last but not least wireless. The last incarnation of Ethernet, 00Base-T, extended Gigabit Ethernet operation over the installed Category copper. The newest version of Ethernet, Gigabit Ethernet, moves the decimal point from one to ten gigabits per second. Cisco GBIC technology provides different types of GBICs that can be used on long-distance runs (up to 70 km). Offer multiple services over single broadband infrastructure single transport technology Business customers networks are evolving and new applications are making their way into mainstream corporate use, using applications such as IP telephony, real-time audio/videoconferencing and multimedia collaboration. Ease of provisioning With Ethernet, there are no expensive and difficult WAN technologies to buy or manage. In its extension to the WAN, Ethernet remains simple, with no changes to enterprise addressing schemes and no complex configurations to understand and manage. Both enterprises and service providers are familiar with Ethernet technology. The ubiquity of Ethernet makes it easy to find human and other resources to manage Ethernet networks. Also Gigabit Ethernet is still Ethernet, it minimises the IT manager s learning curve by maintaining the same management tools and architecture. Economic enablers Low-cost optical Ethernet This fundamental value has been achieved by the tremendous momentum that Ethernet switching has attained over the past halfdecade, which has significantly reduced its Figure 3 Bandwidth delivery costs $/Port/Mbit/s /Month cost structure. A study published in September 2000 showed that the cost of delivering bandwidth through Gigabit Ethernet access is lower compared to other technologies (Figure 3). /0/00 Mbit/s Ethernet is the world s most ubiquitous networking technology. Over 90% of today s networkattached desktops are attached with Ethernet. Compared to other broadband access offerings, these new IP-based, multi-service access networks offer a significantly lower cost per interface. The deployment of simple IP-based architectures eliminates a significant number of infrastructure layers relative to the old-world time-division multiplex (TDM) infrastructure. Since most multimedia and data applications will eventually be deployed via IP-based technology, it makes sense to engineer the network design for IP from the beginning. Multi utilities want to leverage on their existing assets Multi-utility companies own the land where the cables are laid and they can possibly start a business combining their asset with the aggressiveness of new entrants and remain very important in many cities, especially those cities not yet targeted by major service providers. Municipal fibre Local councils have the right of way. Municipally owned fibre, locally controlled, enhances the local economy, quickly meets the specific needs of the municipality and is less infrastructure disruptive in maintenance and installation; streets are not torn up repeatedly. Government as sponsor The fibre infrastructures may equal some of the great infrastructure deployment of the Source: BCE, Sept. 2000, by Peter Sevcik, NetForecast,Waltham, MA SONET ATM Gigabit Ethernet 1

4 20th century, such as electrification and base telephony as an essential to every building in the country. Two Governments are driving this in Europe: in The Netherlands and Sweden. PTTs leverage existing fibre plant Thanks to previous fibre plant installation in the business areas along to the main cities, PTTs can quickly build up the new broadband infrastructures, complementing the digital subscriber line (DSL) access services. They keep growing their fibre plant through consolidated investment for plant rehabilitation and new areas development. Building optical wiring within the building A riser company will deliver a new building with optical wiring included and this will raise the value of the property. Broadband is already a way for property owners, real estate, builders or tenant-owner associations to compete and get tenants attraction. Broadband first-mile competition The Ethernet industry recently decided to christen this market opportunity the first mile in order to emphasise the need to put the end-customer first. The IEEE Ethernet Working Group formed an Ethernet in the First Mile Study Group. Working with over 60 companies and 0 engineers in this Ethernet standards process enables intense market competition at every stage of the value chain, which lowers the costs of components and subsystems and lowers the costs of the systems available to customers, service providers, and other network managers. Solution Architecture The solution architecture shown in Figure 4 enables service providers to deploy contentrich, IP-based data, video and voice networks to residential and business customers. The design consists of multiple Gigabit Ethernet rings aggregated by PoP switches. The Gigabit Ethernet ring uses two GBIC ports on the access switches connecting neighbouring upstream and downstream access switches. There are three main functional areas within a PoP architecture: access aggregation, core backbone (including Internet peering), and local server farms. Segregated PoP architecture, where each functional area is implemented with a separate set of equipment, is also adopted in the metro area networks. So there is an aggregation layer of PoP switches as described so far, a backbone layer of core routers, and a server farm layer of routers and switches connected to servers and Figure 4 Metro Ethernet architecture Internet GBE Links over Fibre Metro PoP Core Router GBE Large Business and Business Parks Universities, Research Institutes Metro Backbone cache engines. For coverage reasons, the metropolitan network can be developed on two layers for the aggregation: feeder layer and primary aggregation layer. The access switch deployed within the building, dedicated to one customer or shared between multiple customers located in the same building, offers superior layer 3 granular quality of service or we could just use the ability to look in to the higher layers of the OSI model in order to mark traffic and conduct proper traffic policing (rate limiting), actually working mainly as a layer 2 switch. The solution in Figure 4 is part of the overall metro framework (Figure ), that Figure Metro framework TDM and GE Private Line Storage and Lambda Residential Voice and Video Resilient Packet Ring Metro Services OSS IP/MPLS Control SONET/SDH CWDM/DWDM Fibre Internet Enterprise AVVID L2/L3 VPN Switched Ethernet Core Router GBE Distribution Rings Dedicated or Shared Access Switches Metro PoP Single or Duplicated PoP Switches Small Businesses, Shops and SOHO Schools, Hospital and Libraries can deliver these services on various underlying technologies, such as resilient packet rings, multiservice provisioning platforms in SDH and native switched Ethernet. The way service providers have to change their mode of operation is to work the way down from services, such as video and voice and/or VPN, through technologies and infrastructure. This is different from historic approaches: building a network and then trying to figure out what you could sell. Service Providers Market Segmentation Due to the availability, cost, and speed advances in Ethernet, many service providers are looking to offer metro Ethernet as a connectivity option to their customers in the metropolitan area. They are now looking to expand their offerings to gain additional revenues through new services, while adding more value to existing services in order to capture incremental revenue and reduce churn. Many green-field or newly established service providers are already offering Ethernet connectivity out to their customers. PTTs are considering Ethernet, either as a pure Layer 2 transport mechanism, or for offering IP virtual private network (VPN) services to compliment their existing SDH, frame relay, or asynchronous transfer mode (ATM) services. 2

5 Figure 6 Potential service providers offering ETTB Biography Service Provider Utilities, Municipalities Main Assets Ducts and tubes Relation with end-users Geo-marketing Real Estate Developers Relation with tenants Buildings and area wiring in the cost of the project (optical) Cisco Systems PTTs CableCos and MSO CLEC These companies may decide to implement an aggressive fibre-to-thebuilding strategy in competition or complementing other technologies enabling broadband local access like DSL, wireless or cable; address specifically the need of bandwidth, with just-in-time provisioning or multiple sites with hosted applications in the same metro area (storage, web, others). Rehabilitations of existing fibre plant In-building wiring Knowledge of the market Existing cable infrastructure Requires partnership with utility Need for renting fibre Ethernet/GE for internal applications, where high-speed trunking between POPs, COs, and Internet data centres is needed, is becoming more common. Each service provider segment, as shown in Figure 6 has a strong reason to adopt and succeed when adopting ETTB. has 13 years experience in the networking industry. He has a degree in Engineering. He Joined Cisco Systems in 199 where he is running the marketing for metro IP solutions today. Previously he was Technical Director for ASONIC AG (systems integrator), and Network Manager at the University of Applied Sciences in Aalen, Germany. He is co-author of Electronic for Engineers and has years experience in standards bodies of DIN and ISO/IEC. 3