NETGEAR Nighthawk CM2500 Cable Modem: features, specs and who it suits

The NETGEAR Nighthawk CM2500 is a DOCSIS 3.1 cable modem built for faster cable internet plans. Its main feature is mid/high-split support, which allows much higher upload speeds than older modems. NETGEAR sells it for use in the US only, as a modem you own and connect to your own router.

What mid/high-split means

Cable internet shares a limited range of frequencies between downloads and uploads. Traditionally most of that range was given to downloads, which is why upload speeds on cable have often been low. Mid-split and high-split arrangements move the dividing line to give uploads more room. NETGEAR says the CM2500 supports this, and that some providers' faster plans need it. It rates the modem for up to 2Gbps down and 1Gbps up.

The listing gives one provider example: a 900Mbps download and 100Mbps upload plan. NETGEAR says the modem works with all major US internet providers, but not with the voice plans of one major provider. Whether your provider has enabled a mid/high-split on your local network is for them to say, so confirm that before relying on the upload figures.

Download and upload speeds in practice

NETGEAR says the modem delivers "10x faster upload speeds" and ties that to multiple people gaming, video conferencing and uploading large files at once. It also mentions easier remote access to home security cameras and files on a NAS. These are things that depend on the upload side, which is why the split matters. Real speeds depend on your plan, your provider and your home network.

Link aggregation for up to 2Gbps

The CM2500 has two Gigabit Ethernet ports. A single Gigabit port caps at 1Gbps, so NETGEAR says you can connect both ports to a router that supports link aggregation to reach up to 2Gbps. Without a router that supports it, one port will carry the traffic and you would be limited to Gigabit speeds from this modem. Check your router's specs before counting on 2Gbps.

Pairing with a router

A modem only connects you to the provider. NETGEAR suggests pairing it with its WiFi 6E or WiFi 7 routers or Orbi mesh systems for the best performance, although the modem should work with other routers. The device is a modem alone, with no Wi-Fi built in.

Owning your modem

Many providers rent out equipment for a monthly fee. NETGEAR presents owning your own modem as an alternative to renting. Check your provider's list of approved modems, and be aware that you become responsible for the device and its support.

Size and installation

The modem measures about 6.8 x 3.7 x 8.2 inches (17 x 9.4 x 21 cm) and weighs 1.1 lb (about 0.5 kg), so it sits upright on a shelf. Installation generally means connecting the cable line, connecting the router, and then activating the modem with your provider. Follow the manual's steps.

Who it suits

It suits US households on a cable plan with fast speeds or high upload needs: home offices, content creators, shared homes with several people online.

What to check before you buy

• Provider list: confirm that your provider approves this model for your plan.
• Voice service: the listing says it is not compatible with that provider's voice plans.
• Plan speed: check that the modem's rated speeds cover your plan.
• Router: make sure it supports link aggregation if you want to use both ports.
• Location: it is made for use in the US only.

The short version

• DOCSIS 3.1 cable modem with mid/high-split support.
• Rated up to 2Gbps download and 1Gbps upload.
• Two Gigabit ports; link aggregation gives up to 2Gbps.
• Modem only, with no Wi-Fi; for use in the US.
• Check provider approval and voice-plan limits first.

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