Netgear CM1000-100NAS DOCSIS 3.1 Cable Modem

The Netgear CM1000 was one of the first DOCSIS 3.1 cable modems on the market, and the reason to buy one refurbished today is simple: full gigabit-class modem technology at a fraction of the price of a new unit. It is a pure modem, no built-in WiFi and no phone ports, which means nothing between your cable line and your router to slow things down, and no monthly rental fee on your bill.

Pair it with any wireless router you like. The router handles your WiFi; the CM1000 handles the connection to your provider.

Quick Specs

DOCSIS 3.1 Speed and Stability

DOCSIS 3.1 is the technology cable providers use to deliver their gigabit tiers, and it improves more than raw speed. OFDM channels make the connection more resistant to noise and congestion than older DOCSIS 3.0 hardware, which translates to steadier throughput at peak evening hours. On plans below gigabit, the CM1000 still pays off: it falls back to 32x8 channel bonding, the maximum DOCSIS 3.0 configuration, so mid-tier plans get full headroom too.

Modem Only, By Design

A standalone modem has real advantages over an all-in-one gateway. When you upgrade your WiFi, you replace only the router. When something needs a reboot, you know which box to power cycle. And because the CM1000 does one job, it does not compromise on it. Connect the gigabit Ethernet port to any router, from a basic dual-band unit to a whole-home mesh system, and your network is live.

Simple Self-Activation

No technician visit needed. Connect the coax line and power, then activate through your provider's app or a quick call with the modem's MAC address. Most activations finish in under fifteen minutes.

Will It Work With Your Internet?

The CM1000 works with cable providers including Spectrum, Cox, Sparklight, WOW!, Astound, and Breezeline in most areas. Two important exceptions: Xfinity removed the original CM1000 from its approved list in April 2026, and Mediacom ended support in October 2024, so this modem is not the right choice for those two providers. Approved-modem lists change periodically, so confirm this model against your specific plan with your provider before ordering. As always, our activation guarantee has you covered: if your provider will not activate it, the return is on us.

Frequently Asked Questions

Does the CM1000 have WiFi?

No. It is a modem only. You connect your own wireless router to its gigabit Ethernet port, which gives you the freedom to choose exactly the WiFi hardware your home needs.

Does it work with Xfinity?

Not anymore. Xfinity removed the original CM1000 from its approved modem list in April 2026. If you are on Xfinity, choose a currently approved DOCSIS 3.1 model instead; our Xfinity collection has options that remain on the list.

What plan speeds does it support?

Plans up to 1 Gbps. The single gigabit Ethernet port tops out around 940 Mbps of real-world throughput, which matches gigabit cable tiers. For multi-gig plans, you need a modem with a 2.5 Gbps port.

Do I need DOCSIS 3.1 if my plan is under a gigabit?

It helps even below gigabit speeds. DOCSIS 3.1 connections handle network congestion better than older hardware, and owning a 3.1 modem means you will not need new equipment if you upgrade your plan later.

Is there any difference between the CM1000 and CM1000-100NAS?

No. The -100NAS suffix is the North American retail SKU of the same modem.

Does the refurbished unit come with a warranty?

Yes. Every refurbished device we ship is tested, factory reset, and covered by our 90-day full-coverage warranty, plus our activation guarantee on modems.