IT departments are being challenged on several fronts. Fewer staff need to manage many more applications, both wireline and wireless. Servers are being consolidated in centralized data centers, so the apps must be integrated across high-speed, wide area networks. To capture this huge opportunity, service providers must move beyond the connectivity model.
Before we converse we must define our terms: a remark attributed to Voltaire. Ethernet is a data transport technology that has become the most popular and widely deployed local area network technology in the world. Carrier Ethernet employs the same technology, but it has been developed in order to overcome the limitations of the original design and enable it to be deployed in wide area networks. See sidebar “Five key attributes”.
Carrier Ethernet (CE) allows service providers to deliver better services using Ethernet as the base technology. CE therefore allows IT to extend the familiar technology that’s already deployed in the LANs, i.e. employ it over their enterprise network. It’s end-to-end Ethernet.
Routers wrap (and unwrap) IP packets inside Ethernet frames and these frames can be transported over all mainstream media, including copper. But when bandwidth requirements increase, optical fiber is the preferred choice: OPEX (
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Alert) is low, speed is high and fiber scales like no other medium.
CE technology has evolved and when deployed in conjunction with carrier-class switches it ensures the predictable delivery of traffic over wide area networks: unlike traditional Ethernet networks, it is not a best-effort service. The characteristics are those of a circuit-switched connection, so it supports the low latency requirements of real-time voice and video traffic.
In a nutshell, Carrier Ethernet has just about everything going for it. In 2008 IDC, an analyst organization, valued the private line market at $40 B (
News -
Alert). This figure encompasses legacy transportation technologies such as SDH/SONET, but eventually the global infrastructure will migrate to CE.
DEPLOYMENT SCENARIOS
Large organizations such as hospitals, insurance companies, banks and utilities can deploy an end-to-end private CE network in order, for example, to backup their databases. Servers are being consolidated into data centers so there is an emerging need to transport massive amounts of data in the most cost-effective way. These networks are established by leasing dark fiber and deploying Ethernet access switches at the various sites.
Alcatel-Lucent (
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Alert) recently has introduced a cost-optimized, customer edge switch that is ideal for this scenario. (Details come later).
Five key CE attributes
1) Standardized services: there is a wide range and no changes to LAN equipment are needed
2) Scalability: millions of users; bandwidths from 1 M to 100 G
3) Reliability: fast detection and recovery times as low as 50 ms
4) QoS: SLAs that deliver end-to-end performance requirements for voice, video and data traffic
5) Service Management: monitor, diagnose and centrally manage the network to provide the carrier-class reliability enterprises expect
The alternative scenario, and for many companies it is the preferred option, is to outsource the wide area network to a service provider. Managed services have been available for some time and now there is a standard (Y.1731) that enables end-to-end performance and fault management. In turn this allows service providers to offer hard SLAs to their customers.
This is clearly a positive development, but is still a service based on connectivity and the market requirement has moved on.
QoS, QoA, and QoE
Enterprises employ a wide range of applications and services: email, VoIP, IM, file transfer, video conferencing, business IPTV (News - Alert) services, storage backup and recovery, etc. Each application has unique requirements for bandwidth as well as timing or delay sensitivity. VoIP can suffer from poor quality and dropped calls. Streaming video may breakup or take a long time to start playing.
There is a popular perception that a high QoS equates to a high QoE (Quality of Experience) and that any quality problems can be accommodated by adding more bandwidth. That perception is wrong but it persists.
In order to optimize the QoE, which is the quality parameter that matters the most, service providers need to manage the quality of the various applications — the QoA (Quality of Application) — all the way to the end user. This means that the optimum QoE comes from a combination of QoS and QoA.
THE NEXT PHASE OF CARRIER ETHERNET
The first phase was Layer 2 best-effort connectivity and there was no service awareness. The second phase brought in predictive connectivity as well as VPN services and improved scalability. The third phase, which Alcatel-Lucent is pioneering, is “Application Enabled” Carrier Ethernet.
An example of this evolutionary next phase is the ability to assure the quality of the individual applications, i.e. the QoAs. Put another way, end-to-end SLAs for the different applications and services that businesses require could significantly expedite the evolution of managed services.
This is an enterprise-centric article, but it is worth noting that the same functionality can be applied to the residential and mobile services, e.g. IPTV and triple/quad play.
Application Enablement is supported by a broader, wider “Carrier Ethernet Framework”, which as illustrated in Figure 1, has a three-tier structure.
(1): The CE transport layer helps operators reduce the cost of building and operating networks that can carry high volumes of business and consumer traffic, the majority of which is data.
(2): MPLS integration helps expand the reach and scale of consumer and business services. This is boosted by the addition of the 7210 SAS (Service Access Switch).
And (3): The application enablement layer addresses operators’ need to leverage their network assets to develop new sources of revenue from specialized, targeted applications
Figure 1. The three-tier structure of Alcatel-Lucent’s Carrier Ethernet Framework. A key design objective is to enable enhanced network capacity and intelligence and allow operators to deal with high-volume, low-value traffic as well as the delivery of advanced, managed services and applications.
THE SERVICE ACCESS SWITCH
The 7210 SAS extends the scope of the company’s Framework, in conjunction with optical, IP/MPLS and wireline access platforms. This CE switch is deployed at the customers’ premises and the price point makes it viable for SMBs as well as enterprises. It employs the same operating system that has been deployed in more than 30,000 IP/MPLS switches and routers that are operational in the networks of 260 service providers in over 100 countries.
A key feature of the 7210 SAS is the ability to provide a seamless extension of service providers’ networks to the premises of their customers and to deliver multiple services over a single Ethernet link. Having the same operating system throughout the network also ensures end-to-end QoS consistency, i.e. it takes application-specific SLAs to the edge of the enterprise network. In turn this simplifies and enhances the provisioning and management of CE WAN services, as well as performance management of the various SLAs.
IDC’S CONCLUSION
IDC provides market intelligence, advisory services, and events for the information technology, telecommunications, and consumer technology markets. They conclude that: “this is a good product release for Alcatel-Lucent. It helps define the Carrier Ethernet challenges, and shows how the company will address them in 2009. It also delivers a new product in an emerging market. We believe other vendors have and will begin to deliver products similar to those of Alcatel-Lucent, but may or may not have the entire end-to-end SLA management.”
Bob Emmerson is TMC's (News - Alert) European Editor. To stay abreast of the latest news affecting the European market, check out Bob's columnist page.
Edited by Stefania Viscusi
