Cable-Optimized EPON Unveils New Realm of Service Options

Karen Schmidt, VP, enterprise marketing, Comcast Business Services

Karen Schmidt, VP, enterprise marketing, Comcast Business Services


By Fred Dawson

October 31, 2013 –Vendor advances building on the cable industry’s landmark alignment of EPON technology with the DOCSIS operations domain are lifting the curtain on an evolutionary path that could profoundly impact the way services are delivered in both the business and residential markets.

These are very early days in the implementation of capabilities tied to CableLabs’ release of version 1.0 of its DPoE (DOCSIS Provisioning of EPON) specifications, but, already, it’s clear the incorporation of Ethernet services over PON (passive optical network) infrastructure into the routine processes used with provisioning and managing cable broadband services has opened a huge new market to the commercial services side of MSOs’ operations. And, judging from emerging technology roadmaps, it could impact consumer services as well.

Notably, CableLabs does not shy away from making the case for pervasive use of Ethernet in its document describing the DPoE 1.0 specifications. “Ethernet is the least common denominator of all modern telecommunications,” the writers say. “Whether in-house carrier services, wholesale, business services or even residential, Ethernet has become the foundation for telecommunications services.”

This is definitely how Aurora Networks is looking at its implementation of the DPoE standard in its EPON products, notes Shridhar Kulkarni, product manager for access network solutions at Aurora Networks, which was the first vendor to bring to market a DOCSIS-provisioning capability associated with EPON, well before a standard emerged. Aurora, which will apply for DPoE 1.0 certification in January, has leveraged its experience as a provider of fiber transmission and node solutions to the cable industry to create an EPON platform that is well positioned to accommodate evolving uses of EPON, Kulkarni says.

“Residential Ethernet services won’t happen tomorrow, but, already, we’re seeing operators making commitments to using fiber-to-the-premises technology for greenfield residential infrastructure,” he comments. “While RFoG (RF over Glass) is the dominant approach at this point, people are beginning to talk about creating a migration to EPON by using Ethernet for the high-speed data element.”

Longer term, the growing use of EPON and the emergence of supporting cable standards plays into another standards initiative underway within the IEEE, namely, EPON Protocol over Coax (EPOC), which, as previously reported, has strong support from leading MSOs and CableLabs. Commercialization of EPOC will allow operators to deliver EPON services over the HFC network, thereby bringing the benefits cited by the CableLabs developers to the residential market.

Kulkarni says Aurora will soon be introducing optical network terminals (ONTs) that support provisioning for cable digital voice, residential gateways and extensions of DOCSIS-related data records for billing EPON services. “We’ve also equipped our EPON ONUs (optical network units) with support for voice interfaces and RF ports to enable legacy video services,” he adds.

A key to operator’s ability to expand the use of EPON will be the multi-service flexibility afforded by universal service platforms. For example, Aurora’s Trident 7, as the central point of aggregation and management in the Aurora product portfolio, has the flexibility to support a variety of platform interface modules, including EPON and GPON as well as legacy services, Kulkarni says.

Along with supporting DPoE provisioning, the Trident7 Element Management System (EMS) supports provisioning for non-DOCSIS applications such as the Broadband Forum’s TR-069 and related access management technologies, which vendors have begun to integrate into cable modems, he notes. EMS also applies XML APIs to integrate multiple types of OSS systems in order to mediate billing, policy controls, QoS, security and other management processes.

As Jay Fausch, senior director of strategic marketing for the Americas at Alcatel-Lucent, notes, the transition to EPON is a natural one for cable operators, who have embraced Metro Ethernet services as the ticket to moving up market from their initial base at low end of the small to medium business (SMB) spectrum. “The primary implementations we see for cable operators relative to EPON are in line with what they’ve already been doing with offerings of Metro Ethernet services,” Fausch says. “But as things become more cloud based and more bandwidth intensive with applications like video conferencing and telemedicine there will be additional reasons for deploying EPON.

“This is all about using fiber efficiently and moving up market,” he adds. “It doesn’t matter whether it’s basic Metro Ethernet, data center interconnectivity or connectivity of cell sites for some type of backhaul, we see our customers looking at PON as the way to get more efficient utilization of fiber plant.”

Where fiber to the premises was once viewed as out of the question for most cable operators in their pursuit of commercial service opportunities, it is becoming almost routine, given escalating demand for high-bandwidth Ethernet services. Comcast, for example has been pursuing aggressive expansion of fiber-based Ethernet services over the past year as the linchpin to its move to the SMB midmarket segment.

“When we look at the products in the midmarket space, we’ve invested heavily in the Ethernet and really do see that as the technology of choice in the industry,” says Karen Schmidt, vice president of enterprise marketing for Comcast Business Services. “We are doing buildouts with fiber at this point and then supplementing it in some cases with the HFC plant.

There’s broad agreement that demand for Ethernet services is on the rise and, with it, demand for increasing carrying capacity over the PON access fiber, which typically is assigned link budgets for serving up to 32 premises ONUs. In a new report on projected spending for Ethernet services in the U.S., Insight Research predicts cumulative spending over the next five years will reach $49 billion, nearly tripling the amount spent over the previous five years.

“Over the next forecast period we project a compounded annual revenue growth rate of 19 percent, with the highest growth levels in the next two years,” says Fran Caulfield, director of research at Insight. On track to generate $5.5 billion this year, Ethernet services will hit $13 billion in 2018, he says.

The small to mid-sized business market happens to be the fastest growing market for Ethernet services, which is good news for cable operators, Caufield notes. “The consumer cable TV market is flat, so MSOs are investing heavily in commercial services, including business Ethernet services,” he says.

Currently, he adds, the fastest growing Carrier Ethernet service is E-LAN, which allows the wide area network to behave like an in-house or campus local area network, followed closely by E-Line, a vast catch-all category encompassing Ethernet Private Line (EPL) and Virtual Private Line (EVPL) for delivering applications over point-to-point connections. On the wholesale side, he says, cellular backhaul may be the biggest demand driver for Ethernet for a while to come, which is another major opportunity for cable operators.

Underscoring the upward pressure on bandwidth that is pushing EPON in cable, Caulfield notes the data rates that are the fastest growing revenue drivers can be found in the segment between 100 Mbps and 1Gps. The industry’s adoption of Carrier Ethernet 2.0 and other standards is creating a more predictable service worldwide, as well as a more operationally efficient and reliable services, he adds.

IDC, which projects U.S. Ethernet revenues will grow from $5.2 billion in 2012 to $10 billion in 2017, says datacenter connectivity, disaster recovery/business continuity and datacenter storage replication are the three primary applications driving adoption of Ethernet. “Growth is particularly strong with Ethernet access to other services such as dedicated Internet access, IP VPNs, datacenter interconnect and now private cloud services,” says Nav Chander, research manager of enterprise telecom for IDC. “Enterprises are continuing to expand the use of Ethernet for VoIP, video, and other real-time applications and are also increasingly interested in on-demand bandwidth.”

As evidence of the dramatic impact of datacenter interconnectivity on the Ethernet market, IDC found in a recent survey of 200 U.S. enterprise CIOs and data center operations staff that the percentage of companies using Carrier Ethernet to connect datacenters went from 35 to 45 percent in one year’s time. These connections are operating at speeds of 1 gigabit-per-second or higher, the survey found.

While Ethernet services make up a tiny fraction of the $142-billion U.S. business services market, and EPON is only a subset of the Ethernet total, the market for EPON is in the sweet spot for cable operators and, as such, represents a far larger piece of the potential pie they’re angling for in the SMB market. For example, says Comcast’s Schmidt, out of the  $10-$15 billion of “telecom spend” represented by SMBs in Comcast’s service areas, “we look on Ethernet alone as being a $3-to-$5-billion annual market, and it continues to grow.”

Nobody has been more aggressive about using EPON than Bright House Networks. “Bright House Networks has been an early champion of PON technologies in general, and EPON specifically, as our default last-mile fiber connectivity solution supporting all of our MetroE and cell backhaul services,” says Craig Cowden, the MSO’s senior vice president of network engineering/operations and enterprise solutions. “Compared with competing alternatives, EPON has clear advantages in capital efficiency, vendor interoperability, bandwidth scalability and standardized provisioning.”

Like other MSOs Bright House is leveraging that standardized provisioning as vendors bring DPoE-compliant platforms to market, in this case with the implementation of Alcatel-Lucent’s newly announced ultra-broadband optical fiber access solution for MSOs. Along with support for DPoE, which Alcatel-Lucent will submit for CableLabs certification in January, the vendor is touting its early lead in 10gigE connectivity and the universality of its 7360 Intelligent Services Access Manager (ISAM) FX fiber platform.

The platform supports line cards delivering GPON (Gigabit PON) and CWDM (course wavelength division multiplexed) point-to-point optical services as well as EPON on a non-blocking backplane architecture that delivers 2 x 100 gbps to each slot in whatever array of access modes the operator chooses, Fausch notes. “We have customers who are utilizing GPON and CWDM today for commercial services and backhaul,” he says. “If they decide they want to migrate to EPON they can do that with different line cards without having to swap out the chassis.”

10G connectivity is definitely on the Bright House roadmap, Cowden says. Indeed, Fausch notes, MSOs in general “are hot to trot with 10G EPON. DPoE, which is meant for interoperability, is now stable stakes in this market. What really sets us apart and what’s gotten us in the door with major operators is we’re way ahead of the game in our 10G implementation.”

There’s another element to Alcatel-Lucent’s play in EPON that could be a sleeper among innovations that could drive the market. This is A-L’s EPON Small Form-factor Pluggable (SFP) Optical Network Units (ONU), a long name for a miniature device that terminates the access fiber link and plugs into the SFP “cages” that now come with off-the-shelf routers for enabling fiber connectivity on LANs. Allowing such routers to host the ONU streamlines the EPON installation process and adds appeal to the cable operator’s offering as a natural extension of Ethernet operations into the wide area.

Thanks to DPoE, when the SFP ONU is plugged into the router, it automatically provisions itself. This is possible because each ONU is treated as a virtual cable modem from the optical line terminal, which in Alcatel-Lucent’s case is the EPON line card under control of the 7360 ISAM FX.

DPoE accomplishes this treatment of EPON components as if they were a cable modem termination systems (CMTSs) and cable modems by using Metropolitan Ethernet Forum (MEF) service network communications known as Ethernet Virtual Connections (EVCs) to emulate a DOCSIS system. The process is very similar to how service mapping is done in the EPON domain, where a centralized scheduler maps Ethernet or IP frame header information to a logical circuit just as DOCSIS maps MAC headers to Service Flow Identifiers.

But as simple as this sounds, the task of bringing MEF service categories into the DOCSIS domain and applying all the OAM (operations and management) functionalities in EPON service management is extremely complex. As CableLabs puts it in the specifications document, “DPoE Networks are capable of supporting all Metro Ethernet services. Full DOCSIS service automation is limited by the work required to develop the service models and automate DOCSIS file-based provisioning and operations.”

Consequently, DPoE 1.0 focuses on the Ethernet service most commonly deployed at this point by cable operators, which is EPL. The service, which can support applications as diverse as credit card processing, medical imaging, data backup, Ethernet VoIP and wireless access backhaul, can be configured to carry voice, video, Internet and data services together over the same connection with different class of service levels based on degrees of latency, jitter, data rates, availability and even transport distance.  And the current specs also support DOCSIS-defined Internet service, including all the functionalities supported by unicast IP such as IP-PBX, T1 circuit emulation, storage network services and IP-VPN. In these instances, everything is treated in over-the-top mode with Ethernet as the underlying transport mechanism.

But the current specs don’t support E-LAN or E-Tree, which provides traffic segmentation in instances where remote locations need to communicate to a central location but not to each other such as cloud service applications and agency or franchise operations of big companies. However, sources say these MEF services will be covered with release of DPoE 2.0 next year.

Further down the road are several important capabilities that promise to expand the applicability of cable EPON all the way into the residential market. These include extension of the DPoE jurisdiction beyond the set-up of MEF and underlying DOCSIS service flows. At some point the specs will include provisioning of high-order services such as PacketCable voice, PacketCable Multimedia, including IPTV, Wi-Fi and residential gateways.