A wireless router is the central piece of gear for a residential network. It manages network traffic between the Internet (via the modem) and a wide variety of client devices, both wired and wireless. Many of today's consumer routers are loaded with features, incorporating wireless connectivity, switching, I/O for external storage devices as well as comprehensive security functionality. A wired switch, often taking the form of four gigabit Ethernet ports on the back of most routers, is largely standard these days. A network switch negotiates network traffic, sending data to a specific device, whereas network hubs simply retransmit data to all of the recipients. Although dedicated switches can be added to your network, most home networks don't incorporate them as standalone appliances. Then there's the wireless access point capability. Most wireless router models support dual bands, communicating over 2.4 and 5GHz and many are also able to connect to several networks simultaneously.
Part of trusting our always-on Internet connections is the belief that private information is protected at the router, which incorporates features to limit home network access. These security features can include a firewall, parental controls, access scheduling, guest networks and even a demilitarized zone (DMZ), referring to the military concept of a buffer zone between neighboring countries). The DMZ, also called a perimeter network, is a subnetwork where vulnerable processes like mail, Web and FTP servers can be placed so that, if it is breached, the rest of the network isn't compromised. The firewall is a core component in today's story. In fact, what differentiates a wireless router from a dedicated switch or wireless access point is the firewall. Although Windows has its own software-based firewall, the router's hardware firewall forms the first line of defense in keeping malicious content off the home network. The router's firewall works by making sure packets were actually requested by the user before allowing them to pass through to the local network.
Finally, you have peripheral connectivity like USB and eSATA. These ports make it possible to share external hard drives or even printers. They offer a convenient way to access networked storage without the need for a dedicated PC with a shared disk or NAS running 24/7.
Some Internet service providers (ISPs) integrate routers into their modems, yielding an "all-in-one" device. This is done to simplify setup, so the ISP has less hardware to support. It can also be advantageous to space-constrained customers. However, in general, these integrated routers do not get firmware updates as frequently, and they're often not as robust as stand-alone routers. An example of a combo modem/router is Netgear's Nighthawk AC1900 Wi-Fi cable modem router. In addition to its 802.11ac wireless connectivity, it offers a DOCSIS 3.0 24 x 8 broadband cable modem.
DOCSIS stands for "data over cable service interface specifications," and version 3.0 is the current cable modem spec. DOCSIS 1.0 and 2.0 defines a single channel for data transfers, while DOCSIS 3.0 specifies the use of multiple channels to allow for faster speeds. Current DOCSIS 3.0 modems commonly use 8, 12 or 16 channels, with 24-channel modems also available. Each channel offers a theoretical maximum download speed of 38 Mb/s and a maximum upload speed of 27 Mb/s. The standard's next update, DOCSIS 3.1, promises to offer download speeds of up to 10 Gb/s and upload speeds of up to 1 Gb/s.