Driven by the convergence of bandwidth-intensive applications like enterprise automation, streaming media, cloud-based services, and mobile data, service providers are pushing their legacy infrastructures to new limits. In the past year the market has seen service providers deploy 100 Mbps service with Ethernet over Bonded Copper, PAETEC announced a 200 Mbps service, and, although with less fanfare, service providers are delivering higher speed on the low end too. Service offerings of 1 and 2 Mbps are being replaced with 10 Mbps service.
As customer applications have become majority IP- and Ethernet-based, Carrier Ethernet is the optimal infrastructure for aggregation/transport of enterprise/business customer traffic in the access network. The real growth is in the requirement for higher bandwidth services that only Carrier Ethernet enables. The Ethernet Services market for business applications alone has grown substantially over the last several years and is projected to grow significantly with a Combined Annual Growth Rate (CAGR) of over 18% year over year through 2015. (See Figure 1.) To meet the increasing demand for bandwidth and speed, service providers are looking to copper and TDM legacy infrastructures to support higher-rate Ethernet Services to enable more customers to transition to Ethernet services faster.
Figure 1: Global Ethernet Services Growth
The Fiber Gap
Today’s carrier access network represents both the greatest opportunity and greatest challenge for carriers to effectively respond to enterprise customers’ requests for ubiquitous Ethernet services. One of the primary challenges is the lack of fiber availability to enterprise buildings. Figure 2 shows that even the most aggressive estimates put the percentage of businesses with fiber access at less than 32% in the United States and even less in Europe.
Figure 2: Business Fiber Availability
The rate of fiber availability has increased over the last few years, but the majority of businesses have only Copper and TDM/SONET media access to the carrier access network. As a result, to deploy Ethernet services quickly and ubiquitously, Ethernet over Bonded Copper and Ethernet over TDM and SONET can facilitate the migration to an all-Ethernet network over time.
To support Ethernet service ubiquity, or Ethernet Everywhere, leveraging existing carrier assets is a must. Ethernet services over Bonded Copper and Ethernet over TDM and SONET offering Ethernet service speeds from 1 Mbps to 200 Mbps help service providers maximize their legacy infrastructure while building out fiber for service to 10 Gbps. In this way, service providers use multiple technologies at a variety of different speeds and capitalize on Ethernet service management tools to differentiate service offerings in the competitive marketplace.
If a carrier is deploying new infrastructure, native 1GigE or 10GigE infrastructure is the optimal solution. However, there are situations where the carrier cannot deploy new infrastructure and needs to leverage existing TDM and SONET infrastructures in addition to copper. Some of these situations include:
Off-net: When leasing Off-net services to reach customers -- not on a service provider’s own network -- they have to use the services that are available. In some markets or end locations, TDM leased line circuits or SONET may be the only solution available. The service provider can lease a DS1, DS3, OC3, or OC12 from the wholesale transport provider, and put their own Ethernet service over it using a Carrier Ethernet solution that provides Ethernet-over-SONET.
On-net in a TDM or SONET-only market: If the carrier hasn’t installed Ethernet switch/routers in the Hub/Central Office (CO) yet, enabling native Ethernet at the customer would require adding switch/router infrastructure at the CO as well. A carrier can leverage their existing TDM or SONET infrastructure as transport to turn up service immediately and not have to wait for an overbuild of Carrier Ethernet to be put in place.
On-net with existing TDM and SONET transport to a location: Even if the market has Carrier Ethernet capability, all customer endpoints may not be enabled. If there is an existing capability to deliver a DS1/DS3 OC3/OC12 is likely delivered by an OC48 or OC192 SONET system. If the system already in place has available capacity to carry an additional OC3 or OC12, it can be a smart choice to leverage that already-paid-for infrastructure for transport. Put an intelligent Carrier Ethernet edge device at the customer premises and use the SONET system as transport.
Note that in all the cases mentioned above, it is important to have a true Carrier Ethernet edge solution that is Ethernet over SONET (EoSONET) enabled. While many SONET Add-Drop Multiplexers (ADM) can add an EoSONET interface card, these lack the multi-service, hierarchical-QoS, flow level service differentiation required for sophisticated Carrier Ethernet services. Most of these SONET ADMs also are lacking in full Y.1731 Ethernet service management capabilities to provide real-time SLA monitoring of the Ethernet service.
Bridge Building Time!
Using a single Carrier Ethernet solution with DS1/DS3/OC3/OC12/GigE interfaces into the existing carrier network provides all the service differentiation and service assurance features required for a true Carrier Ethernet service at bandwidths from 1 Mbps to over 1 Gbps. These example deployments are referenced in Figure 3.
Figure 3: Single or Multi-client Enterprise Access, Mobile Backhaul
In addition to Ethernet over TDM (EoTDM) and EoSONET, Ethernet over Copper-based solutions enable carriers to cost-effectively support a wide variety of applications including high-bandwidth mobile/DSLAM backhaul, enterprise business services over a wide range of bandwidths from 1 Mbps to over 200 Mbps.
One noteworthy point with Ethernet over Copper (EoC) is that higher rates per copper pair (15 Mbps) are now available and successfully deployed. EoC-based symmetric service has enjoyed significant innovation and product/technology advancements over the last few years. From just 2.3 Mbps per pair in 2003 to over 15 Mbps per copper pair today, in fact. Now, customers can successfully deploy over 200 Mbps Ethernet Services over new generation copper-based (EoC) symmetrical Ethernet services by bonding a large number of copper pairs at a fraction of the cost of fiber-based Ethernet services. (See Figure 4.) The same Carrier Ethernet platform can also support EoTDM-based services concurrently. A Washington, D.C.-based enterprise company has connected its new state-of-the-art datacenter to the Internet via PAETEC's EoC, which has been shown to scale to 200 Mbps as needed to accommodate future growth and expansion.
Figure 4: Carrier Ethernet or IP/MPLS Core
Though there is a rich set of service management tools for Ethernet services (1 Mbps – 10 Gbps), not all customer locations can be reached by just supporting Ethernet over fiber services. Reaching all customers with Ethernet over fiber can be cost-prohibitive.
Essentially, multiple technologies or network connectivity options are needed to cover speed and reach for Ethernet services, and then be in a position to ubiquitously offer all the granular service management tools described earlier in order to support the broadest set of customers.
Building the Strongest Bridge
And so, to support Ethernet Everywhere, one needs flexible Ethernet over Fiber (bandwidth rates from 10 Mbps to 10 Gbps), Ethernet over TDM and SONET (T1, DS3, EoOC3, EoOC12, with bandwidth rates from 1Mbps to 1Gbps), and Ethernet over Copper (bandwidth rates from 1 Mbps to over several hundred Mbps).
So, what are the key drivers for Ethernet Services beyond increased bandwidth? Why is Ethernet service management important for the successful deployment of higher bandwidth Ethernet Services?
For successful Ethernet service management there is Ethernet service fault management and performance monitoring. For fault management the key question to answer is: Can the customer's traffic get from end to end reliably and predictably? For Performance Monitoring: Are SLA commitments being met reliably and predictably?
Some key checkbox items when deploying, monitoring and SLA performance verification of high bandwidth Ethernet Services are:
1. Rapid Service Turn-Up. The faster the Ethernet Service is enabled, the faster the time to revenue on the service. CPEs or NIDs that can 'bootstrap' off the aggregator device (zero-touch CPE/NID) in the CO and obtain their configuration data can have a dramatic positive impact in accelerating time-to-service and service turn up, and begins the SLA monitoring/verification for the Ethernet Service.
2. SLA Performance Monitoring and Fault Management. These features are key in continually and proactively monitoring the deployed Ethernet Service and detecting faults and verifying service availability and performance by providing detailed metrics.
Today, there is a broad set of Ethernet service management tools available to meet these requirements: Y.1731, 802.1ag CFM, RFC 2544 Traffic Generator/Receiver, Y.1564. Carrier Ethernet provides 8 classes of service (Ex. Carrier Ethernet 2.0), with ability to profile, police, and shape at the flow level. Carrier Ethernet has the ability to monitor each flow in real-time, providing end-end latency, frame delay, frame delay variation, and frame loss monitoring. With the deployment of these important Ethernet service management tools, Ethernet services can be deployed and SLA commitments can be met with the opportunity to command a price premium for service delivery.
In conclusion, to reach all locations to support Ethernet service ubiquity, or Ethernet Everywhere, leveraging existing carrier assets is a must. By bridging the 'Ethernet over Fiber Gap' with Ethernet services over Bonded Copper and Ethernet over TDM and SONET, carriers can use multiple technologies at a variety of different Ethernet service speeds from 1 Mbps to 10 Gbps and capitalize on Ethernet service management tools to differentiate service offerings in the competitive marketplace.
Vijay Raman serves as Vice President of Product Management and Marketing for Overture. In addition, Vijay works closely with Jeff Reedy, CEO, on driving Overture's strategic partnerships and business development activities. Prior to the merge of Hatteras with Overture, Vijay was Vice President of Marketing and Product Line Management for Hatteras. Vijay is a networking industry veteran with more than 15 years of experience working for premier equipment vendors that led the market in technology innovation. Overture develops and manufactures high-speed Carrier Ethernet Edge and Aggregation solutions that multiply revenue and streamline operational costs by cost-effectively enabling high-capacity Ethernet services over any physical media: fiber, copper, and TDM. For more information, email firstname.lastname@example.org  or visit: www.overturenetworks.com.
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