What is DOCSIS? Why does it matter for business internet connectivity?

DOCSIS, is an international telecom standard that permits high-bandwidth data transfer over a cable company’s hybrid fiber-coaxial (HFC) infrastructure.

Dennis Thankachan

Nov 23, 2022


Heard of fiber broadband? Of course, you have. Ok then, how about DOCSIS? 

Data Over Cable Service Interface Specifications, or DOCSIS, is an international telecom standard that permits high-bandwidth data transfer over a cable company’s hybrid fiber-coaxial (HFC) infrastructure. Although HFC infrastructure is primarily copper-based, DOCSIS standards and equipment allow these networks to see download speeds up to 10 Gbps and upload speeds up to 6 Gbps (this is with the recent DOCSIS 4.0 upgrade), performing up to par with fiber. If you’re purchasing broadband from Comcast, Spectrum, or another cable company, it’s likely that DOCSIS is powering your connection. Although fiber is a superior technology to HFC, fiber still accounts for only 20% of connections in the U.S, so technologies like DOCSIS are super important.


The Story of DOCSIS

More, shall we say, seasoned readers may remember dial-up internet. Don’t shake your heads, millennials and Gen Z – in the 90s, this was how we rolled. Really slowly with interesting noises. 

As the demand for faster internet and greater connectivity grew, a better solution was required. And in December 1996, we got it – CableLabs (an R&D lab for the cable industry) worked with Cable TV companies and found a way to repurpose the hundreds of thousands of miles of coaxial cable used to provide entertainment in millions of American homes every night for broadband access with the invention of DOCSIS.

This stroke of strategic genius leveraged existing infrastructure brilliantly. 

It also put some noses out of joint – notably those early internet service providers who’d already bet the farm on TDM and DSL – copper and phone wire-based solutions that were already long in the tooth back in the ’90s (TDM, or to use its frankly sci-fi-tastic full title, Time Division Multiplexing, is basically the same technology that was used to send telegrams back in the Wild West).

DOCSIS was significantly cheaper than any comparable high-speed internet product on the market at that time, and it triggered an internet arms race. After the Telecommunications Act of 1996 opened the market to all comers, fiber became the infrastructure of choice, as new network operators sought a competitive edge over the might of cable companies.

CableLabs were quick to respond and have spent the intervening years updating DOCSIS to provide speed and performance comparable to that of fiber.

But with every update, fiber providers find new ways to hone their potential advantages, laying many miles of new fiber every year and providing full-fiber solutions like Fiber to the Building (FTTB), which removes all copper from the equation.


DOCSIS vs. Fiber 

So, all these years later, how do these old foes stack up? And what keeps DOCSIS in the game?

It’s primarily about the cost and availability. Despite fiber’s superior performance metrics, in many cases, it’s still a higher cost per Mbps solution that presents an “on-net” option less frequently. If your business doesn’t need an SLA-backed, dedicated internet connection, then you can typically get a high download speed DOCSIS-based HFC option from a cable company for <$300 / month, often with more lenient contract terms than dedicated options and a shorter install interval. Even if you do need a dedicated connection at your site, perhaps a cable broadband option may be your best fit backup connection

And while fiber always outstrips HFC technically, platform updates continue to keep DOCSIS relevant in the modern marketplace.


The Technical Advantages of Fiber

Fiber provides symmetrical bandwidth (most dedicated internet connections are fiber-based) – which means that you can upload data at roughly the same speed, measured in Mbps (megabytes per second), as you can download it. As well as this built-in symmetrical speed advantage, fiber is quantifiably more reliable on other performance metrics such as delay, jitter, and packet loss.

Facing this inequity, the astounding thing is the way DOCSIS has kept pace with a series of updates to electronics and data transmission that manage to squeeze every drop of innovation from a technology that was never intended for these uses.

See below for how the various DOCSIS version updates have kept pace with bandwidth needs over the years and kept cable broadband an effective solution for the cost. 

  • DOCSIS 1.0 - 40/10 Mbps - 1996

  • DOCSIS 1.1 - 40/10 Mbps - 1999

  • DOCSIS 2.0 - 40/30 Mbps - 2001

  • DOCSIS 3.0 - 1.2 Gbps / 200 Mbps - 2006

  • DOCSIS 3.1 - 10/1 Gbps - 2013

  • DOCSIS 4.0 - 10/6 Gbps - 2019


How Can I Upgrade My DOCSIS Version? 

Just ask your Coax internet service provider – 99% of the changes required to upgrade your network to a different DOCSIS version are technical improvements the ISP carries out. Most of this involves upgrading their network hardware / software and in some cases maintaining or upgrading existing cable plant.

At your end, you simply have to make sure on-premises equipment is aligned with the newer protocols and speeds – usually, this means you’ll need a DOCSIS 3.1 modem or a 4.0 modem (many DOCSIS SLAs include the rental of this equipment from the ISP as standard).


What cable broadband speeds are available to me today? 

Although cable companies are currently busy upgrading their networks to accommodate DOCSIS 4.0 nationally, speed and provider availability at a given location will depend on the status of infrastructure at that specific site. If you’re interested in evaluating cable broadband options for your business, you can configure a Best Effort connectivity request via the Lightyear platform with just a few clicks and see what’s available. Alternatively, you can schedule a meeting with our team via the same flow if you have questions.

Want to learn more about how Lightyear can help you?

Let us show you the product and discuss specifics on how it might be helpful.

Not ready to buy?

Stay up to date on our product, straight to your inbox every month.

Featured Articles