Do You Need a Modem and a Router?

Modems and routers facilitate home access to the internet

Broadband is a necessary component for so many aspects of our digital lives. Gaming, watching videos, buying music, and even web browsing depends on it. There's a long line of equipment and services that brings all those bits to you, and two of the components closest to you are the modem and router.

What Is a Modem, and Why Do I Need One?

"Modem" stands for modulator-demodulator. In many homes, when internet adoption was still somewhat new, data transmitted over the same copper wiring that telephones used. However, transmitting the binary zeroes-and-ones of a data stream over long strands of metal isn't easy.

Most Modems Have One Coaxial Input and (Only) One Ethernet Output
Amazon/Zoom Telephonics

So instead, the signal sent as either high or low, and these get translated to the ones and zeroes our computers are expecting. So, when we send data, a device needs to modulate them into the right signal strength, as well as de-modulate signals coming back.

A modem, on its own, connects your home to that outside network, and is identified by your IP address, which is assigned by your internet service provider. If your home had only one networked device, you could plug it directly into the modem and happily surf away. However, most homes today have many networked devices, and you need a way to manage their connections to each other as well as the internet. That's where a router comes in.

What is a Router, and Why Do I Need One?

A router is focused on local area networking. It performs the following functions for devices within your home network:

  • Manages and assigns IP addresses.
  • Acts as the local domain name service.
  • Sends requests, such as for a web page, over the internet on behalf of your devices and returns the results.
  • Blocks incoming requests from the internet. More advanced routers let select requests through.
  • Connects several wired devices, as most standalone routers only offer one Ethernet port.

Do You Need a Modem and a Router?

Every home network requires a device that translates the signals of your cable provider or phone company into the Ethernet most networking equipment understands.

For 2-in-1 Devices, Note the Coaxial Input, and the Multiple LAN Ethernet Outputs
Amazon/Motorola, Inc.

And unless you have only one device in your home (connected to that modem over Ethernet), you need something to manage local IP addresses and maybe provide wireless coverage.

Using 2-in-1 Modems/Routers

Modems and routers need not be separate physical devices. Some modems support built-in routing capability. A single device takes up a single power outlet, and you'll only need to learn how to use one interface to configure and manage your home network. Furthermore, a single device may be less expensive than the buying a modem and router separately.

Most modern cable and DSL providers offer gateway modems by default.

Using a Standalone Modem and Router

However, using a separate modem and standalone router the most prudent choice in a few specific use cases:

  • ISP Support: Your internet service provider may not support these combined models. In fact, there's a chance you're required to use whatever modem your ISP supplies.
  • Placement: While it's convenient to have both of these functions in one device, separate devices give you more freedom of placement. For example, you might put the modem in a closet, but you wouldn't want to stifle the wireless access point in there.
  • Features: Stand-alone routers tend to have more and better features than combined models. If having VPN access, advanced routing, or hardware sharing share on the network is important to you, you're more likely to find these options in a separate router.
  • Performance: If your router kicks the bucket, at least you won't be totally offline. You can still plug a computer directly into the modem. If the integrated router in your combined device goes, you're probably out of luck unless you can solder.