Many users no longer think about wiring network cabling throughout their homes because wireless is so common and easy to deploy. What possible disadvantages are there to skipping the cables and just connecting everything to Wi-Fi?
Deciding which devices should be connected through a physical Ethernet cable and which should be connected through Wi-Fi requires a good understanding of Wi-Fi’s limits, the likely bandwidth usage of each device, where traffic will be flowing, and the bandwidth of the upstream connection to the network.
Wi-Fi Limitations
Wi-Fi access points are rated by their maximum speed: a 300
Mb/s Wi-Fi AP can send or receive 300 Mb/s. The air through which Wi-Fi signals travel is a shared medium—like a single shared Ethernet cable. Because the air is a shared medium, only one Wi-Fi-connected device can transmit or receive at any moment.
One way of seeing this sharing is dividing the available bandwidth among all the connected devices so
• Two devices connected to a 300 Mb/s AP can send and receive about 75 Mb/s each.
• Two devices connected to a 300 Mb/s AP can send 100 Mb/s and receive about 50 Mb/s each.
• Four devices connected to a 300 Mb/s AP can send and receive about 32 Mb/s each.
Waiting for open slots to transmit and collisions imposes some overhead, so actual speeds will be lower than simple division indicates.
Further, existing Wi-Fi sessions have priority over new ones. If one user is streaming a movie, and a second user begins downloading a large file through the same AP, the first user’s traffic will have priority over the second user’s traffic.
Newer technologies, like Multi-User Multiple Input Multiple Output (MU-MIMO), can help the Wi-Fi AP support higher bandwidths for more users. MU-MIMO uses multiple antennas and beamforming to direct signals at different parts of a room, so users in one section of the room do not share the same medium as users in other parts of the room.
Most users will send and receive the largest amount of traffic to destinations reachable through the Internet, so their Internet service speed will have as great or greater impact on their connection speed as their local Wi-Fi network. There is little point in getting a 300 Mb/s Wi-Fi router to support two devices, both of which will send and receive traffic from the Internet when your Internet service is 10 Mb/s.
In some cases, users will stream from a device connected to the local network, such as a media or gaming server. In these cases, the Internet connection speed is not as important as the speed of the local network.
Choosing Devices to Wire You should prefer to wire devices that
• Use a lot of bandwidth for extended periods; these devices will significantly impact Wi-Fi performance.
• Communicate with media or game servers connected to the same local network.
• Act as media or gaming servers.
• Are generally fixed in one place, such as a television or a host normally connected to the network through a docking station.
There is no definite set of rules around what to connect through Ethernet and what to connect through Wi-Fi. The general rule of thumb, however, is less mobile, higher bandwidth devices will perform better if connected via Ethernet.
Configuring the Home Network
Home network wireless requires several configurations—even if the network has only one device. Each section that follows considers one part of the home network configuration.
Configuring the MODEM
MODEMs are generally “plug and play.” The service provider can perform any configuration needed through a remote connection in most modern networks. The biggest questions you need to answer about the MODEM are
• Where should it be located? The MODEM does not need to be close to the router, AP, or other network elements. Any location where the external cable, an internal cable to reach the router, and power are readily available should be fine.
• Are all the lights correct? Like most other networking gear, green lights are generally good, and green blinking lights mean the MODEM is transmitting data. Most MODEMs provide labels describing the meaning of the lights.
Once the MODEM is plugged in and running and the lights look correct, you can configure the router and firewall.
Configuring the Router and Firewall
The router will have at least two interfaces:
• A wide area network (WAN) or outside interface. This interface should be an RJ-45 cable. The other end of this cable should be plugged into the MODEM.
• A local area network (LAN) or inside interface. This interface, or set of interfaces, also uses an RJ-45 connector. This is where you connect a switch, AP, or devices that should have Internet access.
Routers might also have an internal switch supporting four to eight interfaces. It is important to remember these interfaces are switched rather than routed; the entire set of interfaces is controlled as a single subnet.