Engadget Guide: Router USB Ports Can Serve Files, Printers and Backup Internet

Routers, the guide notes, are fundamentally low-power computers with a CPU, memory and a lightweight operating system. Newer models carry more performance headroom and faster USB 3.x ports, which give them access to more powerful network routing features.

The most common use is as a file server. An external hard drive, SSD or even a flash drive plugged into the port can be reached from any device connected to the router, provided the feature is first enabled in the router's settings. The option may appear under names such as File sharing, USB storage device, Media sharing or ReadySHARE, depending on the manufacturer. Once switched on, the storage is accessible over SMB, Samba or FTP, and vendors including TP-Link and Asus publish detailed setup instructions.

Printer sharing is another standard use. An older or inexpensive printer without Wi-Fi can be run wirelessly, so it does not have to be connected to individual computers. Compatibility depends on both the router and the printer, and setup may require installing a utility such as Asus' EZ printer sharing app on a PC.

Some routers also accept cellular dongles through the same port. This does not work on every model, because the router's software has to negotiate a 4G or 5G connection. Where it does work, the cellular link can serve as the primary internet source or as a fallback when the ISP goes down, a configuration known as dual WAN failover or multi-WAN. Modern routers can also share an Android phone's connection through USB tethering, which removes the need for a dedicated dongle but forfeits automatic failover, since the phone must be plugged in each time. Sharing through the router also means existing devices do not have to switch to a different Wi-Fi network.

The guide sets out limits to keep in mind. Many older routers support only USB 2.0, a maximum of 480Mbps, or 60MBps, which means transferring large amounts of data takes hours. Some routers also struggle with portable hard drives, which draw more power than a simple flash drive. The guide suggests choosing a drive with an external power adapter, though at that point a dedicated network-attached storage box delivers better stability and performance. A NAS can typically hold multiple hard drives and use RAID for redundancy, so a single failed drive does not mean lost data. RAID is not a true backup, but the guide describes it as an important first step against data loss.

Printer sharing carries drawbacks of its own, since companion software often has to be installed on the PC. TP-Link, Netgear and Asus all offer utilities for Windows and macOS, but none provides a way to initiate prints from Android or iPhone.

Even with those caveats, the guide says the port can still be used well. It advises against backing up important data on a router-attached storage device, but calls the port valuable for sharing files and temporary media between devices.

Editor's Summary

Engadget's guide describes how the USB port on a Wi-Fi router can host networked storage, share a non-wireless printer and, on some models, provide a cellular or tethered backup connection. It also documents the constraints, including USB 2.0 transfer speeds, power limits with portable drives and the absence of mobile printing support. The guide recommends a dedicated NAS with RAID for users who need more stability, and cautions against relying on router-attached storage for important backups.