Telecommunications

August 7, 2006
Metro Ethernet: Redefining LAN Boundaries

Vishwanathan Iyer

NEW DELHI -- The demand for bandwidth in the metropolitan-area network (MAN or metro) is expanding exponentially as a result of myriad factors, including data-intensive applications, new enterprise business models that rely on the Internet, the growth of broadband services, distributed applications, Web services, IP convergence, streaming content, multimedia, new computing models, networked storage, and business continuity initiatives. This demand is putting pressure on existing networks that use the traditional TDM-based technology, which doesn't have the capability of handling such intensive bandwidth and delay sensitive requirements of Enterprise applications.

Metro Ethernet is the ideal technology to help enterprises scale their existing Ethernet LANs as it uses the similar architecture as LAN in a large metro environment. Metro Ethernet provides the flexibility and high bandwidth to make the boundaries of the Local Area Network disappear. Most enterprises today deploy an Ethernet LAN at each of their locations. Networks carrying traffic between these LANS will work most efficiently when they reflect the same enterprise architecture on a larger scale. The key is to identify a cost effective, scalable and flexible method of transport that can address this demand and support bandwidth intensive applications like streaming video, disaster recovery, storage applications and/or QoS-based applications such as VoIP. This is where Metro Ethernet fits in. Besides addressing the needs of enterprises, Metro Ethernet also serves as the ideal last mile technology to deliver triple play broadband to the residential consumers.

What is Metro Ethernet?

Metro Ethernet is a general term used to describe an Ethernet technology network in a metropolitan area. Metro Ethernet (Metro-E) Service delivers "native" Ethernet connectivity - otherwise constrained to a LAN - across the Wide Area Network (WAN).

Metro-E removes the bottle-neck normally associated with traditional TDM circuits (such as 64Kbps to E-1 connectivity), providing full wire-speed, secure Ethernet between multiple locations using one of the following interfaces – 10Mbps, 100Mbps (Fast Ethernet) or 1000Mbps (Gigabit Ethernet). Ethernet technology's plug-and-play feature also enables a simple migration path from low to high speeds. Therefore, Metro Ethernet makes it relatively easy to integrate and interface end-customer IT systems.

It is used for connectivity to the public Internet and for connectivity between enterprise sites that are separated geographically. It has the potential to increase the cost efficiency and capacity of an enterprise network and enable a wide range of services in a simple, scalable and flexible manner. It allows for centralised file and print services and eliminating the need for server hardware and software duplication across the enterprise branches/offices. Additionally, it also has the potential to carry triple-play broadband services to the doorstep of the residential consumers and deliver a combination of communication services like telephony, e-mail/Internet and entertainment services like video/ music on demand, e-learning, Internet gaming, etc.

Today, service providers are offering Metro Ethernet services successfully. Service providers are deploying Metro Ethernet in the last mile as it has a strong business case because of the advantages it offers. It has a shorter pay back period and quicker RoI (return of investment) compared to any other broadband access mechanism for the enterprise market segment specially. Ethernet offers higher bandwidth than xDSL and runs over optic fiber so they are complimentary technologies.

Metro Ethernet for enterprises

Among the most appealing benefits of managed Metro Ethernet services for the enterprise are service scalability, flexibility, cost-effectiveness, and simplicity.

Ethernet provides enterprises a cost-effective, high-bandwidth option for connectivity and access. The per-port cost for Ethernet CPE tends to be lower, and enterprises avoid costly and complex upgrades of their WAN CPE by simply adding new ports on the switch when necessary. Rather than over provisioning bandwidth because the service provider can offer upgrades only in large increments, the enterprise can buy bandwidth in precise amounts when needed. Finally, high bandwidth in the WAN allows enterprises to optimise their IT resources and cut operational expenses by consolidating servers and storage.

Ethernet becomes automatically operational, which simplifies networking. Ethernet in the LAN and WAN also simplifies network administration by eliminating the need to manage IP addressing and subnet boundaries. Troubleshooting does not add to the IT burden as Ethernet expertise is widely available within the enterprise.

Where traditional access based on time-division multiplexing (TDM) is rigid, complex, and costly to provide, Metro Ethernet services provide scalable bandwidth in flexible increments, with simplified management and faster, lower-cost provisioning. Traditionally, broadband in India has been offered through technologies such as ADSL, which can go upto a maximum bandwidth 25Mbps with variation in the downstream and upstream speeds based on the distance from the central office. Metro Ethernet on the other hand can offer constant speeds of upto 100/1000Mbps without any distance to bandwidth variation in downstream and upstream speeds.

Metro Ethernet forum study shows that 98 percent of the consumers prefer Ethernet over WAN bandwidth. Metro E has the flexibility and simplification of network whether it is point to point; point to multi-points and from any point to any point. There is significant cost savings of the network equipment when using an Ethernet technology.

Metro Ethernet for service providers

Metro Ethernet services enable service providers to capture new revenue opportunities and increase their profitability through value-added services capabilities. Key benefits of Metro Ethernet include:

Capturing new revenue streams: Service providers can capitalise on the growing demand for high-bandwidth applications by offering Metro Ethernet services. Existing services do not offer granular bandwidth; organisations that need bandwidth between T1/E1 and T3/E3 are particularly underserved. By offering managed Metro Ethernet services, service providers can offer bandwidth in increments and build a rich portfolio of connectivity and access services generating multiple revenue streams.

Extending existing ATM and Frame Relay equivalent services: The Metro Ethernet services architecture has the flexibility to extend and evolve service providers' existing ATM and Frame Relay networks. That is, service providers can offer Metro Ethernet selectively to locations requiring higher bandwidth, such as corporate headquarters, while at the same time extending the service footprint to other locations through

Reducing costs for improved profitability: Service providers can provision additional bandwidth on Ethernet faster than they can on ATM and Frame Relay, accelerating time to revenue. Ethernet equipment typically costs less than comparable equipment for ATM, Frame Relay, and SONET.

Increasing profitable services: In addition to basic services, providers can deliver premium services with SLAs to differentiate their offerings and increase margins. Service providers can offer specific SLAs to meet enterprise requirements for QoS to support mission-critical applications involving data, voice, and video. In addition to enabling high-margin SLAs, Metro Ethernet eliminates the metro access bottleneck that has, until now, inhibited service providers from up selling high-bandwidth managed services such as IP VPN, managed IP telephony, storage, and other revenue generating, value-added services bundles.

Metro Ethernet for home consumers

Metro Ethernet offers the end customer a host of advantages as the end customer can avail the benefits of high bandwidth centric functions, all on a single pipe. From their perspective applications such as IP-TV and VOIP will be available on a single network. Some of the advantages are listed below:

Plethora of services: The technology will enable a whole range of bandwidth intensive services such as VOIP, video conferencing, Home CCTV, peer-to-peer application, pay-per-view TV and other online entertainment - music, gaming, etc. besides the traditional e-mail and surfing. Consumers will have the ability to enhance their bandwidth periodically depending on their need.

Improved availability: The technology provides a complete carrier grade solution if the customer requires it. Redundancy is available at all network levels if required and serves as necessary back-up in case of network faults. This means that consumer services are much less likely to be interrupted, resulting in higher service satisfaction to the end consumer.

Reduced cost of services: The advanced transport systems allow for a better view of the network from content source to end-user. Management systems are interconnected across the consumer applications and delivery platforms providing a simplified, consolidated view of operations. This allows the operator to reduce the operational complexity and expenses of managing a large network of sophisticated services and devices to a centralised customer service center or network operations center. This, in turn, reduces the cost of the service to the end consumer.

Where is India at with Metro Ethernet?

In India, leading service providers like Tata and Reliance, among others, have deployment of Metro Ethernet infrastructure across multiple cities. The Metro Ethernet infrastructure is being used to backhaul last mile access technologies like IP DSLAM, WLAN, WiMax for consumer Internet as well as mobile data. The Metro Ethernet infrastructure can also offer granular VPN and Internet services for the enterprise and commercial markets. Other operators are also expected to roll-out services shortly.

Clearly, as broadband penetration in the country makes a steady increase, Metro Ethernet will be the default technology of choice, for the service providers, enterprise and end consumer. To sum it up, Metro Ethernet is set to redefine the boundaries of LAN beyond the enterprise and to the home segment as well.

(The author is business development manager, service provider vertical, Cisco Systems, India and SAARC)