Docsis Gets Its EPON On

Don't go calling it Docsis 4.0, but CableLabs says it will soon release a new set of specs that apply Docsis provisioning and the Docsis back-office to EPON-based MSO networks. (See Docsis to Get EPON Provisioning.)

And don't expect these specs, to be called DPoE (Docsis Provisioning of EPON), to apply much to residential services. They'll mostly come in handy for business-class IP and Ethernet services, a category that major MSOs are starting to pursue as they go after mid-sized businesses. (See Comcast Chases Big[ger] Business .)

That cable has decided not to reinvent provisioning is not a huge surprise. Talk of a Docsis management plane for PON networks began at least three years ago, when MSOs began to extend fiber-to-the-premises (FTTP) networks for use in business service scenarios. (See Time Warner Cable's Fiber-licious RFI and Salira EPON System Talks Docsis .)

That EPON is getting some special cable love is also expected. Although some MSOs, including Cox Communications Inc. and Buckeye CableSystem , have employed GPON for commercial services, the general consensus is that the Institute of Electrical and Electronics Engineers Inc. (IEEE) EPON standard is more compatible with cable's hybrid fiber/coax (HFC) networks. (See RFoG Gets the Squeeze.)

Regardless of who's on which end of the PON religious fight, CableLabs and its members decided it made sense to graft Docsis provisioning to EPON.

"It became apparent to us, while working on EPON interoperability, that we had already solved the problem of multivendor interoperability when we developed the Docsis specifications," said Time Warner Cable Inc. (NYSE: TWC) VP of network planning and architecture Robert Harris, in a release.

In addition to TWC, Comcast and Bright House Networks are among the other MSOs principally supporting the DPoE endeavor. According to CableLabs, Broadcom Corp. (Nasdaq: BRCM), Hitachi Communication Technologies America Inc. (Hitachi-CTA) , ZTE Corp. (Shenzhen: 000063; Hong Kong: 0763), and Finisar Corp. (Nasdaq: FNSR) served as vendor members of the development team and were directly involved in writing the DPoE specs.

Society of Cable Telecommunications Engineers (SCTE) , by the way, is working on a standard called Radio Frequency Over Glass (RFoG), that lets MSOs string fiber all the way to homes and businesses while preserving the cable operator's underlying OSS, headends, and consumer premises equipment, including set-tops and Docsis modems. (See SCTE Moves on RFOG.)

RFoG, which is most often targeted to greenfield deployments, doesn't inherently support PON or offer much in the way of a speed or capacity boost. However, several vendors have developed PON extensions for their RFoG gear. (See Troy Cablevision Plugs In Hitachi's RFoG, Arris Notches RFoG Deal, and MetroCast Rolls With Moto's RFoG.)

— Jeff Baumgartner, Site Editor, Light Reading Cable

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