The Challenges of Ethernet AccessThe upsurge in market demand for Ethernet network services has presented significant challenges for incumbent and alternative carriers alike. In a 2006 survey conducted among service providers, the following requirements were rated as fundamental in delivering carrier-grade Ethernet service:
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Providing ubiquitous Ethernet connectivity;
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Enabling end-to-end quality of service (QoS); and
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Supporting legacy applications over Ethernet backhaul
RAD's EtherAccess® products support the fundamental requirements for delivering carrier-grade Ethernet services.
Most carrier transport networks have been PDH/SDH/SONET-based and are expected to remain so in the near future, while fiber-to-the-business (FTTB) is reportedly connecting less than 15 percent of businesses in metro area networks (MANs). When adding to that the high popularity DSL technology is still enjoying among residential users and small to medium business enterprises (SMEs), it becomes clear that in order to provide a universal Ethernet service and reach a large customer base with current infrastructure, carriers need solutions that would allow them to extend consistent Ethernet services with common attributes over a diverse variety of access technologies.
Ethernet in the wide area network (WAN) has traditionally been an economical, “best effort” service with no provider commitments or service guarantees other than a designated bandwidth capacity. In order to sustain profitability and curtail operating expenditures (OpEx), carriers need tools to cost-effectively monitor and manage their services end-to-end, while providing SLA (Service Level Agreement) guarantees for various service types required by their customers, such as mission-critical applications, voice, etc. Moreover, as Ethernet traffic is likely to traverse several networks, owned by separate providers and possibly of different technologies, carriers need to ensure transparent hand-off of traffic and easy fault localization. OAM (Operation, Administration and Maintenance) is a known mechanism for enabling such degree of network control in ATM, however it had not been considered part of typical Ethernet WAN technology. OAM-enabled Ethernet also allows carriers to manage their services end-to-end throughout the network, using such features as connectivity verification, error detection, performance monitoring, and alarm indication. Read more about Ethernet OAM.
End-to-end QoS, OAM capabilities and SLA enforcement are essential in transforming Ethernet into a standardized, carrier-class service. The growing appeal of Ethernet as the service of choice for all subscriber types is therefore directly linked to the development of new specifications concerning Ethernet connectivity, service and traffic management. Learn about particular Carrier Ethernet network elements.
Packet switched networks (PSNs), and Ethernet in particular, are being increasingly considered alternatives for TDM networks, primarily due to the lower capital expenditures (CapEx) involved in deploying Ethernet equipment, as well as the lower OpEx and higher bandwidth rates such networks are offering. Nevertheless, many operators wish to continue delivering their revenue-generating legacy services in their migration to new networks. As a result, seamless TDM and ATM integration over Ethernet transport is heavily influencing carrier acceptance and is considered one of the basic attributes that define carrier-class Ethernet. Pseudowire (PW) circuit and service emulation enable cost effective and highly reliable support for TDM and ATM services, by allowing carriers to converge legacy traffic within the Ethernet network environment using a single access link and same end-to-end traffic control features.
Realizing carrier control over the entire service path involves extending network visibility into user premises. This is achieved by connecting customer premises equipment (CPE) to the network with provider-owned demarcation devices that are deployed at customer locations, thereby enabling a clear separation between the user and the network. Such implements are known as Customer Equipment (CE), Network Termination Equipment (NTE), Network Termination Units (NTUs), Network Interface Devices (NIDs), Network Interface Units (NIUs), Ethernet Demarcation Devices (EDDs) or Network Demarcation Devices (NDDs). Intelligent Ethernet NTUs (E-NTUs) are a key element in meeting the various challenges service providers are confronted with, by offering additional advanced functionalities such as service and link OAM, end-to-end traffic management starting at the service hand-off point (UNI – User Network Interface), extensive fault monitoring and diagnostics, uplink redundancy, and automated SLA verification
As a leading vendor in the evolving Carrier Ethernet Access market, RAD has developed a suite of sophisticated products offering Ethernet access functionality and versatility that are unmatched in the market. RAD’s EtherAccess portfolio was developed to allow providers to extend their customer reach, regardless of the available access infrastructure, while enabling proactive service management and SLA enforcement with smart Ethernet demarcation. The EtherAccess product line is also designed to support operators in migrating their legacy services to packet networks, to reduce service costs and prevent customer churn. Featuring intelligent Ethernet demarcation units, aggregators and integrated access devices, EtherAccess products ensure a consistent user experience by incorporating common service attributes over fiber, DSL and copper circuits. Furthermore, EtherAccess’ design include support for standardized Ethernet Virtual Private Line (EVPL) and Ethernet Private Line (EPL) services, bringing end-to-end service control to a multi-vendor, multi-access technology environment. Learn about EtherAccess products.
Another important aspect of Ethernet’s progress towards carrier services is the ability to add features and equipment as technology evolves. Establishing interoperability between network components from various manufacturers is therefore essential for both service providers and vendors. Multi-vendor interoperability offers service providers a migration path to new services by encouraging their confidence in relatively easy and reliable installations, and by helping them avoid the constraints of single source, proprietary network designs. At the same time, interoperability allows vendors to gain access into established networks and benefit from low entry barriers into new markets and applications. The European Advanced Networking Test Center (EANTC) stages annual multi-vendor carrier Ethernet interoperability tests. Its largest, and most diverse, test to date was performed in September 2007, examining some 65 devices from 24 vendors. Read EANTC's Vendor Interoperability White Paper.
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