What Are the Benefits of Having a Modem With a Router vs. Separate?

By David Weedmark

Updated August 26, 2019

Modem/router combo units do the work of two devices in one.
i Ethan Miller/Getty Images News/Getty Images

When you sign up with an internet service provider (ISP), they almost always give you the option to rent a modem-router combo box - sometimes called a gateway - at a low monthly fee.

For many homes and offices this will be the ideal solution, but if you're looking to do more with your small network - like adjusting security settings yourself - you may find the combo box is a bit limited.

This is where getting your own gear by buying a modem and a separate router can be an advantage.


Modem router combo vs. separate devices in a nutshell: A combo gives you convenience, while separate devices can give you more features and more control over customization.

Network Terms and Common Usages

We generally use different terms to describe components of a network in a home or a small business, compared to the names of similar devices used in a large enterprise.

Router: In a small network this is usually a Wi-Fi router, which connects to the modem on one side while connecting to all of your devices - like your computers, laptops and tablets - on the other side.

This not only allows internet access to your devices, it allows your devices to connect to each other, too. Most Wi-Fi routers also include ports so you can connect devices to them with cables rather than using Wi-Fi.

Modem: In a small network, this is the device that connects your home or office to an internet service. A modem by itself can connect only one device to the internet at a time, which is usually the router. (For those who are more exact about technology terms, a more precise definition is that modems are used to connect to old-fashioned analog internet services.)

Gateway: This is often what people call a combination modem-router, with a modem and router in one device. (Technology purists call digital versions of modems "gateways," connecting to digital internet services, whether or not the device also serves as a router.)

Pros and Cons of Modem Router Combos

Regardless of which ISP you're using, the choice between renting a combo box or buying your own devices is usually yours. Just know what you're getting into before making the investment in your own equipment.

Advantages of a modem router combo:

  • A single combo box takes less room, requires only one power outlet and requires fewer wires and cables. 
  • A combo box is generally easier to set up, especially if it comes from your service provider and they do the work for you. 
  • Some internet service providers, like Comcast, include additional features with their combo boxes that you can't get if you were to replace it with your own equipment. 

Advantages of using separate devices:

  • Standalone routers usually have more features and more customization possible in the settings than a combo box has. 
  • A standalone modem and router are easier to replace when it comes time to upgrade either device. If you upgrade your internet, you can replace the modem. If you need to upgrade your router, you don't have to replace the modem as well. 

When it comes to cost, renting a combo box isn't usually your only option. You can usually purchase a combo box yourself, saving you money over the course of a year or two, compared to the monthly rental fee.

Using a Separate Modem and Router

Basic setup for a modem and a router isn't much more complicated than using a combo box.

Ensure the modem is the right model for your internet service, as a cable modem is different than a DSL modem or fiber-optic modem. Connect the modem to the cable or phone jack where your combo box was connected.

To connect the router to the modem, connect a cable to the router's WAN (internet) port and then connect the other end of the cable to the modem.

Give both devices five or so minutes to recognize each other before you try to access the internet.