DOCSIS 3.0 vs. DOCSIS 3.1: What You Need To Know

DOCSIS 3.0 vs. DOCSIS 3.1: What You Need To Know

Network professionals have recently been hearing a lot about DOCSIS 3.0 and 3.1, but many don’t know the differences between both standards, nor what they are capable of. In this article, I’ll explain the major differences with these two standards to help you understand if DOCSIS 3.0 or 3.1 is right for your network.


DOCSIS stands for Data Over Cable Service Interface Specification that defines the standard for cable modems to use as well as the communication protocol. It was developed by CableLabs in 1997 and has since gone through several upgrades, including DOCSIS 3.0 and 3.1, which are used today.

DOCSIS is a communications protocol that enables the Internet connection in your home or business via your cable modem. The cable modem uses a coaxial cable to connect to the internet, which allows for high-speed data transfers over regular television cables. Since most people already have coaxial cables installed in their homes or businesses from satellite or cable TV services, a coaxial-based internet connection like DOCSIS is an easy choice over DSL or fiber-optic connections.

What Is DOCSIS 3.0?

Data Over Cable Service Interface Specification (DOCSIS) 3.0 is the third-generation cable modem standard, introduced in 2006 to support bandwidth requirements of modern services and applications.

The DOCSIS 3.0 standard uses Gigabit Ethernet as its physical layer, which doublespeak theoretical downstream speed to 1 Gbps and upstream speed to 200 Mbps compared with the previous DOCSIS 2.0 standard (which is capable of 42 Mbps downstream and 30 Mbps upstream). It also adds support for IPv6 (the 128-bit successor to IPv4 that’s designed to accommodate the growing number of networked devices).

Advantages of DOCSIS 3.0

The goal of the DOCSIS 3.0 standard is to address the increasing demand for high-speed data transmission over cable television (CATV) networks. In particular, it aims to support a variety of high-bandwidth applications such as interactive video, video on demand (VOD), telephony and Internet access.

DOCSIS 3.0 provides several advantages over previous versions of the DOCSIS standard:

  • Higher maximum data rate: The standard specifies a theoretical maximum data rate of 160 megabits per second (Mbps) for download and 120 Mbps for upload.
  • Channel bonding: Data from multiple channels can be transmitted simultaneously over a single cable modem to achieve higher throughput rates.
  • Improved quality of service: The standard offers several mechanisms that enable QoS in terms of traffic prioritization and bandwidth allocation.
  • Multiplexing of multiple services: The standard supports the multiplexing of various data channels over a single cable modem.
  • Capacity and reliability improvements: DOCSIS 3.0 offers three different modulation schemes that enable higher data transmission rates with increased reliability.
  • Potentially lower power consumption: The standard is designed to enable lower power consumption at the cable modem compared to previous versions of the DOCSIS standard, thereby reducing power consumption at the network access device (NAD).
  • Lower latency: The standard supports short packet transmission at low latency.

What Is DOCSIS 3.1?

What Is DOCSIS 3.1
What Is DOCSIS 3.1

DOCSIS 3.1 is the latest version of the international standard for data over cable systems, released in 2013 by EuroDOCSIS and CableLabs, and it provides a 10X increase in speeds: 10 Gbps downstream and 1 Gbps upstream. It’s designed for next-generation gigabit service packages that are already becoming available from major cable providers across the country.

Advantages of DOCSIS 3.1

DOCSIS 3.1 offers a number of advantages over DOCSIS 3.0. The most significant are increased throughput and reliability of service, thanks to:

  • Increased spectrum: DOCSIS 3.1 supports up to 1 GHz of bandwidth for downstream channels and up to 204 MHz for upstream channels, compared with the 42 MHz upstream that DOCSIS 3.0 offers. This increase in the spectrum is achieved by moving from 6 MHz to OFDM modulation, which allows multiple data streams to be broadcast within the same frequency channel.
  • More efficient modems & chipsets: DOCSIS 3.1 supports new forward error correction (FEC) modes such as low-density parity check codes (LDPC), which are more efficient than the Reed-Solomon FEC used in previous versions of DOCSIS — this means higher data rates can be achieved without losing signal integrity at the receiving end.
  • Support for IPv6 addressing: Like all current service providers, Comcast will eventually need to move entirely over to IPv6 addresses because the supply of IPv4 addresses is expected to run out before 2020 due to the explosive growth in Internet-connected devices including smartphones and tablets). To achieve this transition while still maintaining support for legacy IPv4 devices requires IPv6/IPv4 network address translation (NAT), which enables IPv6 devices to access IPv4 networks. DOCSIS 3.1 can provide stateful IPv6/IPv4 NAT, which enables customers to use both addressing schemes and requires no changes to customer devices or the Internet itself.
  • Improved security features for cable modems (CM): DOCSIS 3.1 provides a number of security and intrusion prevention features, including firewall protection from intrusion into the cable modem itself.

What’s The Difference Between DOCSIS 3.0 And DOCSIS 3.1?

The difference between DOCSIS 3.0 and DOCSIS 3.1 is simply the speed by which they can transfer data:

DOCSIS 3.0 (which stands for Data Over Cable Service Interface Specification) can transfer data at speeds of up to 1 Gbps downstream and 128 Mbps upstream.

DOCSIS 3.1 is the most recent standard and can transfer data at speeds of up to 10 Gbps downstream and 2 Gbps upstream.

The technology used to achieve these faster speeds is more complex than DOCSIS 3.0, so DOCSIS 3.1 modems are more expensive than their predecessors. However, this cost difference is expected to shrink over time as DOCSIS 3.1 becomes the new industry standard and its modems are mass-produced in larger quantities.

Features DOCSIS 3.0 DOCSIS 3.1
Maximum upstream speed 200 Mbps 1 Gbps
Maximum downstream speed 1 Gbps 10 Gbps
Throughput 256-QAM (42.88 Mbps per 6 MHz channel) 4096-QAM (1.89 Gbps per 192 MHz channel)

Why Choose One Over The Other?

Why Choose One Over The Other
Why Choose One Over The Other

DOCSIS 3.0 is a great option for most people — unless you need more bandwidth. If you’re trying to decide between DOCSIS 3.0 and DOCSIS 3.1, you probably don’t need the extra capabilities of DOCSIS 3.1 — unless you have a very large family or run a business from home with lots of employees who are all connected to your network at once. And even then, it’s unlikely that you’ll see much of a difference between the two technologies, since the speed of your network depends on many other factors besides the type of cable modem technology you choose to use.

Why Upgrade To A DOCSIS 3.1 Modem?

DOCSIS 3.1 is the newest technology being deployed by cable internet providers, and it enables them to offer faster speeds than ever before. It also provides new features like 32×8 channel bonding, which improves performance at longer distances from the cable node or when your home Wi-Fi network is busy.

If you have a DOCSIS 3.0 modem with 32×8 channel bonding and are experiencing poor performance, upgrading is a great idea because your current modem may not be able to deliver optimal speed at longer distances or when other devices are connected over Wi-Fi.

What Happens When You Upgrade To A DOCSIS 3.1 Modem?

Right now, it’s really not necessary — because DOCSIS 3.1 has been around since 2013, it’s still pretty new tech compared to DOCSIS 3.0, which was first introduced in 2006 and became widely adopted in 2008.

Why Isn’t Everyone Using DOCSIS 3.1?

DOCSIS 3.1 wasn’t around in 2010. It only became a thing in 2013, when the specification was completed and passed on to manufacturers.

In 2010, DOCSIS 3.0 was still relatively new. It had first been approved in 2006 and started to roll out in 2009*-*the same year Internet traffic began to explode with the rise of video streaming sites like Netflix and Hulu, as well as the growing popularity of smartphones and tablets. So the focus at the time was on getting DOCSIS 3.0 out there, not on developing a new standard for cable modems.

But Now That DOCSIS 3.1 Is Here, Why Isn’t Everyone Using It?

Cost is one factor: There’s no question that DOCSIS 3.1 modems are more expensive than their predecessors, but that’s because they’re so much more efficient: The silicon chips are denser, which means they pack more processing power into a smaller space. That makes them more energy-efficient and less costly to produce, but it also means they cost more upfront.


If you are curious about the differences between DOCSIS 3.0 and DOCSIS 3.1, I hope that this article has served as a helpful introduction to the two. At their core, both standards came about due to their respective cable companies’ pursuits of higher internet speeds; however, this was only in pursuit of a common goal- faster internet speeds for their customers. As these industries continue to grow and evolve with the rise of cord cutting and smart home technologies, internet speed and bandwidth will be at the forefront of discussion.