Why Cable Hearts EPON

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

spc_markl 12/5/2012 | 4:16:26 PM
re: Why Cable Hearts EPON

One of the biggest reasons for cable TV companies moving in an EPON direction is just for the superficial reason of wanting to be different than the telcos.

Mark, Telecom Pragmatics

Jeff Baumgartner 12/5/2012 | 4:16:25 PM
re: Why Cable Hearts EPON

Heh, well that too. I've also had some folks play off to me in the past that EPON is more cable-friendly in general. JB

paolo.franzoi 12/5/2012 | 4:16:25 PM
re: Why Cable Hearts EPON


I think that is a really good statement Jeff.  It is a great way to justify the difference.  But seriously, the technology is not friendlier...the standards bodies MIGHT be friendlier.




Jeff Baumgartner 12/5/2012 | 4:16:23 PM
re: Why Cable Hearts EPON

 Thanks, that makes alot of sense, too. Also was told that some MSOs -- Cox and Buckeye, for example-- started using GPON because they got into this early.  Probably makes some sense to circle back to those guys to see if they have any changes in store. Buckeye's also a CLEC, so it may just stick w/what it's got. Cox, meanwhile, is absent from the public list of DPoE backers CableLabs shared when the specs were announced, so they may be taking a pass on EPON for now since they've already picked a horse and switchouts probably make no sense at this point.... or perhaps they can go with EPON in the new deployment areas.  JB

Galileo 12/5/2012 | 4:16:22 PM
re: Why Cable Hearts EPON

This is not necessarily true. MSOs are looking at business services and for those EPON offers something that GPON can't - being symmetrical. Which for many business applications can be very important.

There is also a trend of using off-the-shelf demarcation solution that Telco are using in EPON environment, allowing to benefit from the MEF standards as well as the EPON capabilities.


victorblake 12/5/2012 | 4:16:19 PM
re: Why Cable Hearts EPON

I'm sure it has nothing to do with the 40M+ EPON ports deployed globally. It couldn't possibly be because it's been around longer, it's more mature, lower cost, there are more vendors, it HAS a 10G standard (symmetric), it's 10G standard is backwards compatible, and OH BTW, even ITU-T will eventually standarize on the 10G-EPON PHY.

If GPON is so great, why are the GPON ONLY (chip set and system) vendors building OMCI for EPON ? Why ? Because they are preparing for their move to EPON. That's why.

And if anyone did their actual homework they'd know where EPON was already deployed in North America.


paolo.franzoi 12/5/2012 | 4:16:19 PM
re: Why Cable Hearts EPON


So, PON is simply awful for anything except T-1 replacement style services.  Redundancy is simply not there.

Now, as to symmetry....GPON can easily support symmetrical services and does.



spc_markl 12/5/2012 | 4:16:19 PM
re: Why Cable Hearts EPON

GPON is far from being perfect.  However, I firmly believe that an objective look at all of the evidence shows that EPON equipment falls short of being as attractive to deploy as GPON hardware for any applications.  Unfortunately, when it comes to Ethernet, these arguments can turn into religious battles.  We can go back and forth 500 times and I am probably not going to convince you and you are probably not going to convince me.  That being said, I still respect your point of view.


opticalwatcher 12/5/2012 | 4:16:15 PM
re: Why Cable Hearts EPON


Do a Google search for XGPON2--10G symetrical and backward compatible.

No need for religious wars.  ITU will have standards for both, since EPON and GPON are both widely used throughout the world and COs will want to minimize their upgrade costs. (see G.987).



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