Enabling Carrier-Class Ethernet Services

Thanks to new, intelligent Ethernet demarcation technology, carriers can finally begin delivering high-value-and highly valued- Ethernet services

For years, enterprises and carriers alike have expected Ethernet to extend to wide area networking as there are so many gains to be realized by having LANs and WANs share Ethernet as a single protocol. Benefits include scalability, the elimination of expensive LAN/WAN interfaces, the leveraging of existing enterprise expertise and the ability to get the exact bandwidth needed.

The holdup? Ethernet, which was designed only for local area networking, doesn’t offer the demarcation points found in Tl/T3- based services, leaving the carrier unable to identify where its network ends and the customer’s network begins. The resulting lack of near-end/far-end performance parameters has limited Ethernet services to being “blind services” that are unsatisfying for both customers and carriers.

The shortcomings from the customer’s perspective is that blind Ethernet services can’t provide the QoS, monitoring, test and customer network management capabilities that are the hallmarks of Frame Relay and Private Line services. From the carrier’s perspective, a blind service is a commodity offering, unable to support a price tag that justifies broadscale rollout. And so carriers and their customers continue to deploy separate WAN protocols that bring substantial complexity and higher implementation costs.

This situation has been corrected with the introduction of new technology that provides a precise, useful and highly intelligent Ethernet demarcation point between carrier and customer networks. Intelligent Ethernet demarcation comprises two primary components, located at the customer premises, that are key to extending carrier Ethernet services:

* the user-network interface (UNI), which defines the service level agreement (SLA) or service personality, including service policing and definition, and

* the network interface device (NID), which provides the operations, administration, maintenance and provisioning tools needed to support monitoring and testing on both sides of the demarcation point.

Working together, the demarcation’s UNI and NID enable Ethernet’s expected WAN benefits and position Ethernet services as a highly suitable replacement for traditional WAN services.

The UNI in Ethernet Demarcation; Service Policing and Definition

The intelligent Ethernet demarcation’s UNI provides the CIR, PIR and burst parameters needed to define the QoS/CoS of Ethernet services on a port or VLAN basis; the use of VLANs enables multiple Ethernet services, such as Dedicated Internet Access and/or Transparent LAN Services, to be carried in a single Ethernet connection to the customer. This function is extremely visible to the end customer because it defines the look, feel and personality of the Ethernet service.

More importantly, locating the service UNI at the customer premises enables service and prioritization at the point where full- rate Ethernet is rate-limited for the lower bandwidth requirements and price points of many Ethernet services. Performing this function at the rate-limiting point is essential to the proper prioritization of such latency-sensitive services as VoIP and video. The customer premises location of the UNI also enables remote additions and changes to the service, eliminating truck rolls for service upgrades and changes.

The NID in Intelligent Ethernet Demarcation: Performance Monitoring and Remote Testing

The intelligent Ethernet demarcation’s NID provides a full suite of RMON Etherstats plus internal buffer performance, enabling carriers to monitor SLA conformance on both sides of the demarcation point and to analyze performance trends over time. This valuable data also provides a performance log for billing and SLA purposes, and provides advance indication of performance degradation before an outage occurs. Carriers can make this data available to customers through a web portal to facilitate customer network management, as is often done with Private Line or Frame Relay services.

Should a service outage occur, intelligent Ethernet demarcation provides remote visibility and control of the demarcation point, reducing or eliminating the need for truck rolls in problem solving. The carrier can employ remote Ethernet loop-backs and pattern generation/detection for remote testing, and can remotely determine if the CAT5 cable connected to the CPE is open circuited, short circuited or properly terminated. Open or short circuits can be located it to the nearest meter for precise diagnosis of cabling problems, which can then often be corrected by the customer.

Deployment Today

Intelligent Ethernet demarcation or Etherjack technology is currently available in all products from Covaro Networks. It is also available in a stand-alone Etherjack configuration to work with existing transport systems and services. Covaro’s family of edge transport products support a wide variety of first mile technologies that accommodate copper, fiber and leased DS3/DS1 applications. Covaro products enable carriers to provide their customers with the level of value they expect in WAN solutions-and to differentiate those services so that they provide the path to meaningful and profitable offerings.

For more information, visit Covaro Networks at www.covaro.com.

Copyright Horizon House Publications, Inc. Nov 2004