NETGEAR CM500V Cable Modem with Voice: features, specs and who it suits

The NETGEAR CM500V is a cable modem with built-in voice support. It connects a home to a cable internet service and also supplies up to two phone lines. NETGEAR says it is certified for Xfinity Internet and Voice, so it is meant as a customer-owned modem for that service, used with your own router.

Who the service must come from

This is the most important point about the CM500V. NETGEAR states that it is certified by Comcast for Xfinity and is not compatible with Verizon, AT&T, CenturyLink, DSL providers, DirecTV, DISH or non-Xfinity voice services. A modem has to be approved by the service provider, so confirm that your provider supports this exact model, CM500V-100NAS, before you plan around it.

What DOCSIS 3.0 and 16x4 mean

DOCSIS is the standard that cable modems use to carry data over the coaxial cable. Version 3.0 introduced channel bonding, which combines several channels to raise speed. The CM500V bonds 16 downstream channels, for receiving data, and 4 upstream channels, for sending it, which is the 16x4 in its name.

NETGEAR recommends it for cable plans up to 300 Mbps. The description mentions speeds up to 680 Mbps, which is the modem's own capability, so the lower plan figure is the safer guide for matching it to a service. The actual speed you get also depends on your plan, wiring, router and devices.

Voice and phone lines

The voice feature supports Xfinity Voice with up to two telephone lines. NETGEAR lists caller ID, 3-way conference calling and call forwarding among the enhanced call features. Phones connect to the modem's phone ports, which suits households that still use a landline-style service.

Connecting your devices

The modem has a single Gigabit Ethernet port. NETGEAR says it works with any WiFi router: connect the router to that port, and the router serves your wireless devices. The modem has no WiFi itself, so you will need a router, or a single computer connected directly by cable.

The listing also names compatibility with Windows (7, 8, 10, Vista, XP, 2000), Mac OS and other systems running TCP/IP, and common web browsers for setup.

Size and weight

The listing gives dimensions of 12.8 x 11.5 x 16.7 inches and 1.8 lb. Those most likely describe the packaging, so the modem itself should be smaller.

Who it suits

It suits Xfinity customers on plans up to 300 Mbps who want to use their own modem, particularly those who also use Xfinity Voice and need two phone lines. It does not suit faster plans or other providers.

What to check before you buy

• Provider approval: confirm that your provider lists the CM500V as supported, and that your plan includes voice if you want phone lines.
• Plan speed: compare your plan speed with the 300 Mbps recommendation.
• Router: you'll need a separate WiFi router for wireless devices.
• Single port: only one Ethernet port is provided, so a router or switch handles the rest.
• Activation: the provider usually has to activate the modem on your account. Follow their steps.
• Age of the standard: DOCSIS 3.0 is an older generation than DOCSIS 3.1, which matters if you expect to upgrade your plan.

The short version

• A DOCSIS 3.0 cable modem with 16x4 channel bonding and voice support for two phone lines.
• Certified for Xfinity Internet and Voice; not for other providers.
• Recommended for cable plans up to 300 Mbps.
• One Gigabit Ethernet port; works with any WiFi router.
• Model CM500V-100NAS.

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