If you use the Internet, you are likely using both a modem and a router. But what are they and how do they work together? In a nutshell, the modem is the door to the internet while the router routes the internet (and its traffic).
While you can have a separate router and modem, you can also find devices that combine both functions – hence the confusion you have. We'll discuss both components in detail and explain how they work together.
Brad Jones / Digital Trends
Modem is short for "Modulator Demodulator", which means that it modulates transmissions to receive and transmit data. It is the door to the internet that receives and sends data between cables / phone lines and all devices in your home. Imagine that as an interpreter who makes everything possible and translates the Internet from the massive infrastructure highways to the smaller routes in households and offices.
The modem is your point of contact for the World Wide Web. Comcast's Xfinity is currently the largest cable operator in the US, with 40 states. This is followed by Charter Spectrum, which covers 43 states. These and similar broadband providers “rent” modems as part of their subscription plans so that you can access their subscription-based service. However, you can purchase compatible modems separately from each dealer to reduce monthly costs. Either way, you'll need one to access the internet.
How it works
Modems usually have lights / LEDs on the front so you can see what's going on at a glance. One light indicates the device is receiving power, one indicates it is receiving data from your ISP, and one indicates that the modem is successfully sending data. Here you start with a troubleshooting scenario: If the send and / or receive lights are blinking, your ISP is likely having problems or something is going on with the connection outside. Another LED indicates that wired devices are accessing the Internet.
Before we go any further, be aware that modems are not just for a coaxial cable connection. Broadband can also be operated via a digital subscriber line or DSL. Access to this internet ramp is via telephone lines instead of coaxial cables, so the connector socket looks no different from physical phones on land. DSL tends to be slower than wired broadband and is useful in rural areas where phone lines already exist. However, there is no infrastructure that supports wired TV and Internet services.
Routers can be designed for either cable or DSL connections. However, both types have several additional Ethernet ports that are used for wired devices with a suitable port or adapter. These can be desktops, laptops, HDTVs, game consoles, printers, and more. If you want to get the most out of your broadband connection, using these ports for your hardware is the best option, especially if the ports support speeds up to one gigabit per second (also known as gigabit ethernet).
The router is a stand-alone device that connects to an Ethernet port on the modem and forwards network / internet traffic to the connected devices. Routers usually have a dedicated, color-coded Ethernet port that provides a physical connection to the modem (WAN or Wide Area Network) and four additional Ethernet ports for wired devices (LAN or Local Area Network).
Thus, the router sends and receives network traffic from the modem with one connection and forwards all of this data through its four Ethernet ports and over the air over the 2.4 GHz and 5 GHz bands. Despite the numbers given, the wiring is faster than the wireless one. We still recommend using Ethernet if you want to get every ounce of bandwidth out of your subscription. But, of course, you can't do that with smartphones, and laying ethernet cables on every wall is downright ugly.
Routers come in all sizes, prices, and exaggerated promises. On the wireless side, they can contain two or more external antennas, depending on the model. The more spiky antennas there are, the better the WiFi coverage – at least in theory. Your connection speed will still depend on your proximity to the router and the technology used to make that connection.
While most existing routers use the 802.11.ac standard (Wi-Fi 5), newer routers can support Wi-Fi 6, which we explain here. Wi-Fi 5 enables three outgoing and three incoming streams (3 × 3) in the 5 GHz band with up to 433 Mbit / s each. They are accompanied by three incoming and three outgoing 802.11n streams (3 × 3) in the 2.4 GHz band with 200 Mbit / s each. The latest update to the Wi-Fi 5 specification, also known as Wave-2, adds a fourth stream for additional bandwidth.
How it works
If this is all confusing, just imagine a bullet train. It arrives at your home via the modem, travels at full speed to the train station (router) and is redirected to a destination. If the target is a wired connection, it plows ahead at full speed. If the destination is wireless, its speed will depend on how many tracks / streams can be used at the same time (one, two, three or four), how much those tracks need to be congested, and how far the station is from the destination. The train loses speed the further it is from the station.
The term "to" means that the hardware can physically support these maximum speeds, but you won't see them here either. Part of the "congestion" slowing down your local data train is your neighbor's network spreading love in the same airspace. There is also interference from equipment inside and outside your home. A router with multiple external antennas with amplifiers will help reduce all of that unwanted noise.
Typically, routers choose the ideal channel for the 2.4 GHz and 5 GHz bands with the least amount of interference. The 2.4 GHz band is divided into 14 channels, while more than 20 are dedicated to the 5 GHz band. However, if you have connection problems it can sometimes be helpful to manually change the channels in the router's web-based interface. There is even more to it than that in terms of the speed that can get into the tough technical field and turn your head.
Check out our list of the best WiFi routers you can buy right now. Some of the routers we tested include the ZyXEL Armor Z2, Linksys Max-Stream AC2200, Linksys WRT3200ACM, and more.
Router / modem combination
Unfortunately, there is no official name for this particular device. Comcast calls it a "gateway" while Spectrum simply calls it a modem. Regardless, the idea comes to you: It's an all-in-one device that looks like a typical modem, but crowds a router inside. This combination unit can be beneficial and disadvantageous depending on how well you want to manage your network.
In a typical stand-alone modem, you can adjust the firewall settings, open ports for certain traffic, assign addresses, etc. The add-on router essentially provides a secondary firewall for better protection, as well as parental controls, device management, usage statistics and more. When you combine the two, you lose that second aspect of the firewall and possible customizations not provided by equipment rented from ISPs.
Another point to consider is that your broadband provider may charge you an additional fee for cellular service even though you are “renting” an all-in-one. Spectrum calls this a "Home Wi-Fi" charge, which will appear on your bill for an additional $ 5 per month and only apply to modems with a company-leased built-in router. For complete control and a lower monthly bill, consider provisioning your own standalone router.
But wait! There is more! A newbie has arrived to crash the network party. It is similar to routers but differs in delivery. In particular, the router is a single unit that broadcasts an internet connection like a radio tower. The further away these broadcasts are, the weaker the signal, which results in a slower speed. In a moving car you can achieve the same effect: the further you are from the city, the harder it is to hear your favorite music station.
In addition, the 2.4 GHz band is ideal for penetrating objects and walls. However, the throughput speed is slower than the 5GHz link, mainly due to congestion. Meanwhile, 5 GHz is faster and less congested, but struggles to penetrate objects and walls.
One way to solve this problem is to purchase a second wireless extender device. It captures the signal generated by the router and repeats it in areas beyond the range of the router. This is helpful in dead ends, but the downside is that repeaters will receive an already degraded signal unless you actually have a wired ethernet connection between the router and the extender. These extenders are sold in a variety of sizes and strengths, from wall-based units to solutions that are the same size as routers.
The arrival to alleviate all of these problems is web-based networking. Kits are usually sold with two or three identical units, so the setup does not consist of a router and an optional extender. Instead, you play the router role by making a physical connection to the modem outlet and then forwarding all traffic to and from the wirelessly connected nodes. Instead of a single unit sending an internet bubble, you have multiple units creating web-based coverage.
What is special about these kits is that you have a connection: the kit determines whether your device should use 2.4 GHz or 5 GHz. Also, they may not be able to tell that your wireless devices are switching from one node to another as you move around the house. The downside is that these mesh networking kits are usually not cheap. Hence, unless you are willing to spend the big bucks every time an updated kit hits the market, the investment can be long term.
Kinda Sorta Mesh
Ultimately, this category combines two connectivity styles into one product. We saw this in Netgear's Orbi kits, which offer two nearly identical units that work like a mesh network kit. However, a unit is clearly a router, which has everything you can find in most standalone routers. The second unit is a satellite, but it does not "repeat" the signal coming from the router-class unit.
In this setup, the two units have three connections: a 2.4 GHz band and a 5 GHz band, which all wireless devices can access. The third is another 5 GHz link that is only used by the Orbi devices. This is a private, high-speed highway that no other device can access. That's the big difference between Orbi and other web-based kits. These nodes use the same 5 GHz storage space as all attached devices, so data transfer is slower due to the traffic. There's nothing on the Orbi special highway except Orbi-to-Orbi chatter.
We tested the Orbi RBK40 kit here and the more expensive (and larger) Orbi RBK50 kit here.