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Enough with the cable broadband monopoly myths

By 3 January 2011 6 Comments

Nearly a year late to the party, Nate Anderson repeats the myth that the FCC concluded that higher speed broadband is turning into a Cable DOCSIS 3.0 monopoly outside of Verizon FiOS fiber to the home (FTTH) territory because the fiber to the node (FTTN) VDSL2 technology used by other Telcos can’t compete.  This is wrong on many levels because the FCC didn’t make such a conclusion and FTTN can compete with Cable.

I asked Blair Levin (the man in charge of that National Broadband Plan) to clarify last April and he debunked the notion that any such conclusions had been drawn.  Furthermore, the more important metric is actual concurrent usage capacity and FTTN architecture does hold the upper hand on actual capacity.  I’ll repeat this explanation below Figure 1 which I’ve published on previous occasions.  Under higher usage loads which will be more common as video streaming like Netflix becomes more common, DOCSIS 3.0 has the least capacity even if they offer the fastest symbolic peak speeds.

UPDATE 1/4/2011 - In fairness to the Cable operators, I should clarify that the lower capacity doesn’t mean Netflix will break since Cable providers work to keep congestion low enough such that people rarely notice slowdowns even during peak usage.  Even a high definition Netflix stream at up to 4 Mbps probably won’t be affected by Comcast’s fair share network management scheme where the heaviest users may experience some throttling during peak usage times to make room for low bandwidth users.  Even if the bandwidth is temporarily halved from 12 Mbps to 6 Mbps, the Netflix stream will probably not be effected.  But if too many Netflix users occupy the same Cable loop, the cable provider will need to upgrade before users experience bitrate drops with Netflix.  The point I was making was that people shouldn’t automatically assume cable DOCSIS is the faster network and that Cable and FTTN are very competitive technologies.

Figure 1 – How broadband technologies compare under load

Figure 1 compares the potential bandwidth performance of broadband technologies on the access portion of the network.  It assumes 10 homes sharing an FTTH node and 150 homes sharing a DOCSIS 3.0 node.  Also note that the total capacity numbers are based on “signaling rates” and actual performance will be 10 to 20 percent lower due to overhead.  “Average user activity” indicates the average per subscriber bandwidth consumption and not the percentage of activity on the entire network.  So if we have 20% of cable broadband subscribers at 10% link utilization level and 80% of the subscribers idle, the average user activity of all subscribers is 2% link utilization.

Cable operators will always be able to offer higher peak speeds than copper networks which means cable will have a monopoly on bragging rights over copper based broadband services.  That does not translate to a monopoly over any significant percentage of the broadband market much less the entire broadband market.  Telco operators will continue to be able to offer substantially higher minimum guaranteed speeds even under high neighborhood usage levels.  This is one of the main reasons Telco operators didn’t need to deploy BitTorrent throttling technologies like their cable competitors.

It’s also noteworthy that FTTN technology will continue to offer increasingly fast peak speeds and AT&T has steadily ramped up to 24 Mbps with their “U-verse” branded product.  That confirms that most of AT&T’s FTTN footprint is well over 25 Mbps and more likely 32 Mbps.  This is using a single cable pair and the Telcos can easily leverage two pairs and nearly double capacity when they need to compete in the 50 Mbps market, when more than a few percent of broadband subscribers want the service.

As signal processing technology improves in copper technology, FTTN speeds will steadily climb to 100 Mbps and beyond.  We already have technology called vectoring that can create a third virtual cable pair that can nearly triple FTTN speeds.  These developments will keep FTTN competitive to DOCSIS 3.0 for all but the symbolic bragging rights market for some time to come.


  • Tech at Night: The New Year Begins | RedState said:

    [...] voted on Net Neutrality, but the job of picking apart the “case” for it goes on. George Ou dissects cable Internet advertised speeds and what they actually mean under real-world use. Spoiler: if you’re on cable Internet [...]

  • Chris Hansen said:

    The problem that fair share fixes is usually not in the last mile. It is in the transit.

    The “last mile” almost always has extra capacity whether it is in telco, broadband or wireless. It is the reason that most IP service providers oversubscribe their networks regardless of Layer 2 technology. In broadband the extra capacity in and of itself provides the ability to do bandwidth sharing beyond the fiber termination without contention.

    Perhaps the real issue here is access to transit and the cost associated with distribution rights for content. MSOs pay for rights to commercially produced media titles for on-demand distribution and build huge datacenters and CDNs to house them. They are in direct competition with pure content providers like NetFlix, Alphaline, Hulu, YouTube, etc. Historically, a cable provider had bandwidth geographically constrained to a physical link between the subscriber and the head-end. It created a defacto “monopoly” for access to commercially produced media delivered to a mostly passive customer. With MSOs now transporting Internet traffic beyond the headend and onto the ubiquitous peered networks they service an interactive customer and incur additional transport costs. They also facilitate their competition.

    Within the Net Neutrality ruling the FCC was correct in stating that ISPs historically allowed for equal access. But few of the historical ISPs were also providers of revenue generating content. The market has changed – and so has the technology.

    Why should MSOs facilitate their competition? Is it implied that a consumer’s standard access subscription provides them an “all you can eat” model of Internet consumption? Maybe. If so, then graduated or “premium” offerings should be in the market mix.

    Why should there be any restrictions on CDNs? Akamai has the ability to actually prevent network congestion with their predictive algorithms and distributed DNS architectures! CDNs like Akamai aren’t part of the problem they are part of the solution.

    To assume that MSOs have a monopoly in access is a stretch. DOCSIS is merely a competing access technology. Both fiber to the curb provided by telcos and wireless technologies like WiMax and 4G-LTE will provide enough bandwidth to support heavy content like MPEG47 and HTTP streaming. In IP networks video is “just an app.”

    The consumer has options.

  • Tech at Night: The New Year Begins said:

    [...] voted on Net Neutrality, but the job of picking apart the “case” for it goes on. George Ou dissects cable Internet advertised speeds and what they actually mean under real-world use. Spoiler: if you’re on cable Internet [...]

  • George Ou (author) said:


    When there’s only 80 or 160 Mbps of DOCSIS 3.0 downstream capacity, there is most certainly a congestion problem in the last mile.

    For the Telcos, their congestion starts on the second mile and above, but we’re talking gigabit links which are less susceptible.

    WiMAX and LTE will most certainly NOT handle video on demand loads of anything beyond very low bitrate video.

  • Richard Bennett said:

    Well, yes, as people move to streaming, sharing becomes less effective because the duty cycle changes. The parameters for DOCSIS are pretty flexible due to node splits, virtual node splits, and channel bonding beyond the DOCSIS 3 limit. The new gear in the field permits bonding 6, 8, or more channels. Cable has 2.5 Gbps to work with as it is, but making the most of it requires some fairly serious deployment of new switches and reconfiguration of a network that was designed for MPEG transport first and IP only as an add-on.

    Crawford’s and Anderson’s fundamental error is the hubris of trying to predict what happens in 5 – 10 years when technology isn’t sitting still. These people don’t have the technical knowledge to cash the checks their hysterical personae are passing.

  • Tech at Night: Deregulation(!), Regulation, Cable TV | RedState said:

    [...] undermines the legitimacy of FCC intervention in the market. So they have to manufacture false claims that there isn’t really any [...]

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