DPoE Pushes the Growth of Cable Business Services

The cable industry's success in the commercial services sector, while perhaps not overwhelming, is a solid moneymaker.For the most part, however, operators have marketed to the small- and medium-size business (SMB) segment of the overall potential market. It's understandable: Most of cable's infrastructure is in residential neighborhoods, where small businesses are concentrated. Operators, being human, have largely stayed with a familiar and comfortable set of technologies -- and where they could make pretty good money with relatively easy competition. Additionally, compared to larger enterprises, SMBs are a relatively accepting customer base.Some operators -- such as Cox, Bright House and Cablevision's Optimum Lightpath -- offer sophisticated fiber services. That remains the exception rather than the rule, however, and there is little industry standardization on approaches to advanced fiber services.That is beginning to change as the industry rallies around the nascent DOCSIS Provisioning of EPON (DPoE) standard. These efforts are on the fast track. There was an interoperability event in January and, according to Curtis Knittle, CableLabs' director of digital video services, others slated for May and August. In addition, during the week of Feb. 14, the consortium held a meeting in Tampa, FL, to move the ball forward on the DPoE 2.0.The technical demands and challenges of moving up to the big leagues are significant, however. Mannix O'Connor, director of marketing for Hitachi Communication Technologies of America, reports that the industry has been working on the issue for quite some time. It was officially taken over by CableLabs around the time of Cable-Tec Expo in New Orleans in October last year.At this point, experts say, some of the most exacting and demanding services needed by corporate users are still beyond the capabilities of EPON (which of course stands for Ethernet passive optical networks). Even exempting these most demanding services, a large potential customer base exists.Challenges AheadThat's the good news. The challenge is that provisioning and servicing EPON using cable's existing DOCSIS structure will require the industry to meet several challenges.The first is to work out a way for DOCSIS to dip into and work harmoniously with other standards, most notably those written by the Metro Ethernet Forum.The details of the challenge are complex, but it is conceptually straightforward. O'Connor says EPON today generally uses the management information base (MIB) database structure, while DOCSIS uses the type length variable (TLV) approach. The databases hold myriad instructions on how to do things such as count packets received and count bad packets and good packets. CableLabs is going through the process of enabling the databases to work together.Another challenge for CableLabs and those working with it is to create an ongoing testing regime for interoperability between hardware and software from different vendors. This is old hat for cable vendors, but may be new for vendors more accustomed to life in the telco world. The telephone industry tends to create closed ecosystems that differ between carriers. While the underlying standards can be the same, the management details differ enough to make full interoperability between the different ecosystems impossible.Finally, the players must add elements to the DOCSIS management layer to enable it to perform demanding tasks that are necessary in business environments but not required in the residential services arena. They simultaneously aim to simplify the management layer as much as possible by removing elements of DOCSIS that aren't needed in a business environment, such as channel bonding.Enterprise-level business services clearly are more demanding than residential or SMB services. For cable operators to compete against established fiber carriers, exacting demands of service level agreements (SLAs) must be fulfilled. The meeting on Feb. 17 was aimed at higher level functions."We are verifying how fault management functions are deployed," reports Zeev Draer, VP of marketing for MRV Communications, a vendor of optical products. He says questions involve determining the appropriate allowable level of latency, how it is measured, how to measure frame loss and availability, and other issues that are vital in high-demand business environments.Dealing with SLAsIn the residential environment, outages result in grumbling and perhaps a day's credit. In the business world, they mean breached SLAs, penalties and, ultimately, sullied reputations. That means that sophisticated systems designed to nip problems in the bud must be included. "The assumption is that if you see significant loss, you need to trigger critical alarms to the NOC and provide the right measurement in order to [confront issues] even before the customer knows that there could be a problem," Draer says.The bottom line is that DPoE is a demanding transition. "Business services can be different than residential services," notes Paul Runcy, Broadcom's product line manager for DOCSIS Mediation Layer (DML) Software for DPoE. "They include MEF-type services, e-private line, VPN services and others. Business customers have different requirements than residential customers."The cable industry is well positioned in the higher end of the commercial services business. The bottom line, however, is that it won't be easy.Carl Weinschenk is a reporter at BTR. Reach him at [email protected].