 | Issue: | Asia-Pacific II 2006 |
| Article no.: | 5 | |
| Topic: | Ethernet – reaching the network edge | |
| Author: | Tuvia Barlev | |
| Title: | President, CEO and Co-Founder | |
| Organisation: | Actelis Networks | |
| PDF size: | 48KB |
About author
Tuvia Barlev is the President, CEO and Co-Founder of Actelis Networks. Prior to co-founding Actelis Networks, Inc., Mr Barlev was head of the R&D organization at Teledata, a high-speed communications company, where he led the DLC R&D department. Previously, Mr.Barlev held top management positions in government research organizations as head of several elite communications projects. Mr Barlev holds a Bachelor’s and a Master’s degree in Electrical Engineering, both with honours, from Tel Aviv University.
Article abstract
The Ethernet has been the standard protocol for office networks for two decades. Now, based upon new IEEE standards, it is becoming the protocol of choice for metro networks. Versions of the new Ethernet ‘first mile’ (EFM) access standards let Ethernet be used with either copper, fibre or hybrid networks, inexpensively and reliably to provide high-speed broadband connections. Using whatever networks are in place, and not waiting to replace copper with fibre, EFM provides fibre-level performance over any in-place network.
Full Article
Traditionally service providers have called it the ‘last mile’. It is the link between the provider’s central office, CO, and the customer premise, CP. In 2001 the IEEE began a project named ‘p802.3ah’ to define a set of technologies to make Ethernet a viable access network technology. During the project meetings, the term First Mile was coined to signal a change in attitude towards customers by putting the subscriber first rather than last! Whether you call it the ‘access network’, ‘first mile’ or ‘last mile’ network, it remains the critical link to the delivery of high performance broadband services to both residential and business subscribers. Until now, a variety of technologies has been tried in the first mile network, but none has broken through the bandwidth bottleneck. The use of standard Ethernet technology in carrier networks is revolutionizing metro networking. Now Ethernet is being deployed in access networks to extend Metro Ethernet services deep into the subscriber network. Ethernet is already becoming the networking protocol of choice for carrier networks just as it did for the enterprise LAN over the past two decades. Ethernet is a protocol that is used everywhere, by everyone. Ethernet in the First Mile, EFM, provides a standard way to deliver a seamless link between subscribers and the carrier network with Ethernet technology end to end. The Ethernet revolution in the access network enables carriers to offer profitable next generation applications and services to both business and residential subscribers. As an access technology, Ethernet offers three significant advantages over legacy first mile technologies: • EFM provides a native interface between private subscriber Ethernet LANs and the carrier Ethernet network; • Ethernet provides a future-proof transport for existing data services, as well as emerging packet video and voice applications; • Ethernet is a simple, globally accepted standard that ensures interoperability across a broad set of products from many suppliers. The EFM standard provides an effective way to extend high performance Ethernet services to meet the growing subscriber demand. The standard greatly extends the reach of Ethernet (Figure 1) and defines specific interfaces for deploying Ethernet on both existing voice-grade copper as well as new fibre-optic networks. While there is no doubt that fibre optics will ultimately replace the copper infrastructure, the cost, time and complexity of building these new fibre networks is creating a demand to deliver reliable ‘fibre-like quality’ services over the existing copper network. Twisted-pair copper wiring dominates the first mile. So the primary objective for the IEEE 802.3ah Task Force was to develop a technology to exploit the existing voice-grade copper infrastructure in the first mile – within residential neighbourhoods as well as within buildings. Millions of subscribers are currently using DSL, digital subscriber line, technology for moderate-speed Internet access. While DSL solutions today rely on cell-based ATM, Asynchronous Transfer Mode, transport, EFMCu, EFM copper standardizes the delivery of bandwidth-efficient, Ethernet packets directly over copper at speeds of 2Mbps for long reach and 10 Mbps for short reach in both directions (symmetrically). Using the existing voice wire infrastructure keeps deployment costs to a minimum, as there is no requirement for new cabling inside or outside the residence or business. By reducing service provider capital expenditures for implementation, EFMCu will serve as the easiest, lowest-cost and immediately deployable solution for providing feature-rich, high-speed access and services to subscribers. For the first time, service providers, governments and private enterprises have a cost-effective solution for extending their Ethernet networks without having to deploy fibre. Eliminating the need to install fibre- optic cable removes a fundamental barrier that has inhibited the adoption of Ethernet in the public network. Using multi-pair bonding (aggregating, bonding, multiple telephone lines together can effectively multiply data transfer rates) service providers can offer high performance (10-70 Mbps) service over a reliable infrastructure with resiliency built right in! EFMCu using multi-pair bonding provides the subscriber with a fibre-like experience, and gives the service provider the ability to offer universally Ethernet services over both fibre and copper media. Deployments for this application have been taking place for some time. However, the EFM standard eliminates the proprietary nature of these early pre-standard implementations and guarantees the vendor interoperability required for large public networks and mass volumes. EFMCu is an attractive access solution for both residential and business users. It is spectrally compatible with other legacy services (PSTN/ISDN, T1/E1 and DSL), so they can co-exist in the same cables. A secondary objective for the IEEE P802.3ah Task Force is standardization of a physical layer specification for point-to-point fibre with Ethernet at speeds of 100 Mbps and 1 Gbps spanning lengths of at least 10km over single-mode fibre. This aspect of the standard is not much more than a minor modification of the existing standard for Ethernet over optical media. The 10km reach supports a broad range of applications without the need to build costly infrastructure. EFMF (EFM fibre) will specify a 100 Mbps and 1 Gbps, full-duplex single mode fibre transport for the access network – a direct point-to-point connection from the central office to the customer premise. In addition, EFMF specifies support for both single and dual point-to-point fibre for 100 Mbps access. The EFMF topology will provide business subscribers with cost-effective opportunities for replacing expensive T1 and T3 links. EFMF is also a candidate for fibre-to-the-home, FTTH applications. EFMF could drive down costs of single-mode fibre access to a point where it will replace multi-mode fibre and allow operators to build a complete network based solely on single- mode fibre, although this may be slow to develop. The limited deployment of fibre in public networks – with less than 4 per cent coverage as of 2005, unlike EFMCu, which reaches over 90 per cent of potential subscribers – will significantly restrict the ability of service providers to offer Ethernet services if they rely solely on fibre. The EFM technologies – EFM copper and EFM fibre – are complementary and competitive at the same time. Carriers deploying Ethernet in their networks will have the option of deploying EFM solutions over a variety of first mile infrastructures. As stated earlier, the fact that existing voice grade copper links over 90 per cent of subscribers makes EFMCu a compelling option for reaching a high percentage of prospective subscribers with Ethernet services. In ‘greenfield’ applications, areas with newly built networks, or where fibre networks exist, EFM fibre can be used. EFM fibre solutions also work well in newly built office parks with fibre installed outside and inside the buildings or in new residential subdivisions with FTTH. Ethernet over copper wire is the best fit for existing neighbourhoods and business parks where a voice-grade copper infrastructure exists. This also holds true for multi-tenant units, MTUs, or multi-dwelling units, MDUs, collectively called MxUs. MxUs include apartments, hotels and office buildings. However, there may be a mix of EFM service feeds into or between buildings, and within larger buildings. Extending metro Ethernet services from the optical core into the copper access network is a cost effective and fast way to reach potential customers with high value Ethernet services. Leveraging the existing copper infrastructure allows carriers to reach subscribers without the delay and expense of deploying new fibre- optic facilities. In some cases, a combination of technologies will exist in the first mile. For example, fibre cable can be laid in the same trenches when new water, electrical, sewer or gas infrastructure is installed. However, many of the buildings may still require access via copper wiring. In these deployments, known as fibre to the building, FTTB or fibre to the curb, FTTC, the network operator can supply a hybrid fibre and copper EFM solution. EFM hybrid, combining high-speed fibre with universally available copper EFM technologies, represents a promising way to reach a large percentage of potential subscribers. The flexibility of EFM deployments allows service providers and network operators to market their EFM access solutions to a broad base of users, including those with fibre to their homes and business offices, those with only copper wiring in the first mile, and those with a combination of fibre and copper. By eliminating multi-protocol conversions, low bandwidth links and by creating a universal technology, Ethernet in the First Mile is a future-proof technology for a variety of existing and next generation applications. The selection of interoperable, inexpensive equipment will be substantial, and the network design will be flatter, enabling more services at lower deployment costs. The new standard takes advantage of the millions of miles of existing voice-grade copper infrastructure. It enables new fibre networks with a set of standard interfaces that will extend the reach of Ethernet to the personal edge, delivering a wide range of next generation applications and services to both business and residential subscribers.
