Nothing against GPON, but there are plenty of reasons why the cable industry has decided to apply Docsis-style provisioning to EPON as MSOs look to go up market and deliver broadband services to mid-sized businesses.

And those reasons extend to good ol' economics as well as the technical path EPON is currently on, Doug Jones, the VP of access technologies at Comcast Corp. (Nasdaq: CMCSA, CMCSK), said last week at Light Reading Cable's The Future of Cable Business Services conference in New York City.

For starters, EPON, an Institute of Electrical and Electronics Engineers Inc. (IEEE) standard, is "nicely priced" and offers gear from multiple suppliers as MSOs figure out how to affix Docsis-based order entry and management tools to the technology, Jones said.

"The economics of EPON and GPON are about the same," he added.

EPON is also symmetric, and appears to be on a quicker path to symmetric 10Gbit/s speeds, while XG-PON is likely still two years out. And Jones likes EPON's upgrade path, noting that MSOs will be able to swap in 10-Gig cards and turn up services without changing out the customer-facing EPON equipment. "Upgrading to 10-Gig is as seamless as it can be," he said. (See Moto Finishes Two XG PON Trials and Verizon: Huawei No Shoo-In for XG PON .)

Cable all but hitched its fiber-fed, commercial services wagon to EPON this fall when CableLabs announced the imminent release of the DPoE (Docsis Provisioning over EPON) specifications, citing backing from major MSOs such as Comcast, Time Warner Cable Inc. (NYSE: TWC), and Bright House Networks . DPoE is expected to factor in significantly as cable operators more aggressively extend Metro Ethernet services to businesses with up to 100 employees, and possibly more than that later on. (See Docsis Gets Its EPON On, Docsis to Get EPON Provisioning, Comcast Chases Big[ger] Business , and Cable's $5B Biz Services Bonanza .)

DPoE "spoofs" the Docsis back-office, meaning cable won't have to learn a new system and train people to operate it. "Why reinvent the wheel?" Jones asks.

Cable's also happy that EPON equipment offers MSOs a cross-section of interoperable gear, which gives EPON vendors an entrée into this new market while allowing MSOs to still buy off-the-shelf equipment and preserve their Docsis back-office investments.

DPoE: What's next?
Cable will soon be putting that theory to the test. Jones said the first DPoE CableLabs interop is scheduled for the third week of January, with additional interops slated for every subsequent quarter through 2011.

Cable's also working on a "Phase II" DPoE platform that will add support for elements such as E-Line and ELAN. Jones anticipates that piece to be done in time for the 2011 Society of Cable Telecommunications Engineers (SCTE) Cable-Tec Expo, slated for Nov. 15-17 in Atlanta.

Jones said Comcast is testing EPON and DPoE in the lab, predicting that the MSO could begin to deploy the technology "in a few markets starting next year."

— Jeff Baumgartner, Site Editor, Light Reading Cable