DOCSIS stands for data over cable service interface specifications, the key being “cable service.” The standard defines how your modem relays cable internet signals going to and from your home. If you have cable internet, whether it’s from Cox, Spectrum, Xfinity or one of many regional cable internet providers, you have a DOCSIS-compliant modem.
Modern cable modems are compliant with DOCSIS 3.0 or 3.1. Specifications for DOCSIS 4.0 have been released, but DOCSIS 4.0 modems aren’t yet available for retail purchase.
If you’re shopping for a new cable internet modem, you’ll have the choice of DOCSIS 3.0 or 3.1. As the numbers suggest, the two modem versions are similar, but I recommend opting for DOCSIS 3.1 if you don’t want to wait for a new 4.0 modem.
What are the differences between DOCSIS 3.0, 3.1 and 4.0?
Despite the simple one-tenth difference in versions, DOCSIS 3.0 and 3.1 modems vary in performance, pricing and availability. DOCSIS 4.0 would imply a bigger jump in performance, but the improvement largely has to do with upstream capacity. Here’s a quick look at the advantages and of each.
DOCSIS 3.0 modem advantages
- Price: DOCSIS 3.0 cable modems are generally cheaper than their 3.1 counterparts.
- Availability: You’re likely to have more options, including used or refurbished devices, when shopping for a DOCSIS 3.0 modem.
DOCSIS 3.1 modem advantages
- Speed: DOCSIS 3.1 cable modems support faster speeds than DOCSIS 3.0 modems and are thus better suited for high-speed plans, especially those with gig speeds or higher.
- Security: DOCSIS 3.1 modems may offer better online security than 3.0 models, especially if you purchase a modem-router combo device.
DOCSIS 4.0 modem advantages
- Upload speeds: DOCSIS 4.0 is designed to “significantly increase upstream capacity,” according to CableLabs, the organization that sets and tests DOCSIS specifications.
- Future proof: DOCSIS 3.1 is the current standard, but 3.0 is still in use, nearly two decades after its introduction in 2006. It’s safe to assume that 4.0 modems will be useful for many years to come.
