Ethernet cable categories: a practical primer for UK homes

What the category number actually tells you

Every Ethernet cable is built to a standard, and the standard specifies two things that matter at home: the maximum frequency the cable can carry (measured in MHz) and the speed it supports over a given distance.

Cat 5e is the oldest standard you are likely to encounter still in use. It supports Gigabit speeds at the lengths typical inside a house, and for most households it remains adequate. The limitation shows up in noisier electrical environments or runs longer than about 50 metres, where crosstalk — interference between wire pairs inside the cable — becomes more noticeable.

Cat 6 is the sensible default for a new installation. It uses tighter twisting and often a physical separator between the wire pairs, both of which reduce crosstalk and push the frequency ceiling higher than Cat 5e. At household distances, a Cat 6 cable is noticeably more consistent under load.

Cat 6A goes further still, shielding each pair individually and raising the ceiling high enough for 10 Gigabit connections over the same distance that limits slower cables. For a home router feeding a streaming device, that headroom is not strictly necessary today, but the cable will outlast several generations of routers.

Check next: look at the sheath of any cable already installed in your home. The category is printed in small text along its length, usually alongside the manufacturer name and a sequential metre marking.

Shielded versus unshielded — when it matters

Most domestic Ethernet cable is UTP: unshielded twisted pair. The twisting alone handles interference well enough in a typical house. Shielded cable (STP or FTP) wraps each pair, the whole bundle, or both in foil or braid. It costs more, requires grounded connectors to work properly, and adds stiffness that makes routing through walls harder.

The case for shielded cable at home is narrow. If a cable run passes close to a consumer unit, alongside mains cabling for a long stretch, or through an outbuilding with fluorescent lighting, shielding can prevent the occasional dropped packet that shows up as a brief stutter in a video stream. In a standard semi-detached or flat, unshielded Cat 6 is almost always sufficient.

Check next: if your cable run passes through a garage, utility room or alongside a long run of mains wiring, consider Cat 6 FTP rather than the standard UTP version.

Cable length and what happens at the far end

The 100-metre limit for copper Ethernet is a hard electrical boundary, not a rough guide. Signal quality degrades gradually as the run lengthens, so a 90-metre cable will work, but it leaves almost no headroom for the patch leads at each end, which count toward the total.

In most houses the practical concern is the opposite: very short runs. A 0.5-metre patch lead connecting a wall socket to a smart TV introduces negligible loss regardless of category. Where category choice pays off in a short run is build quality. Cheap Cat 6 cable with thin conductors and loose tolerances can underperform a well-made Cat 5e cable at the same length.

If you are setting up a wired connection for a streaming device in a bedroom or a home-office setup, buy cable from a supplier who prints conductor gauge on the packaging and avoid very thin, flat cables sold primarily for concealment — they are fragile and difficult to terminate reliably.

Check next: measure the full path the cable will take, including vertical drops and any routing around door frames, before buying. Add a short allowance at each end for the patch connection.

For households that also use AirPlay to send content between devices, the guide to AirPlay setup at home covers the network conditions that keep that working reliably alongside a wired run.

Putting a wired connection to work for streaming

A wired Ethernet connection removes the two most common causes of interrupted streaming: Wi-Fi congestion and variable signal strength. When a device is wired directly to the router, the connection speed is determined by the router port, the cable category, and the device's own network adapter — none of which fluctuate the way a wireless signal does.

For devices that support it, a wired connection is worth the effort of routing a cable. Android TV boxes, MAG boxes, and most smart TVs have a physical Ethernet port. Connecting any of them via Cat 6 to the router removes an entire layer of potential problems.

UK IPTV, delivered over a home internet connection with no dish or satellite contract involved, depends on that connection being stable. A wired Cat 6 run to the room where you watch most often is the single most reliable improvement most households can make.

If your household includes a room dedicated to sport — Six Nations weekends, for instance — the Six Nations channels guide for busy parents goes into the viewing setup in more detail.

Check next: confirm whether the device you plan to wire has a Gigabit Ethernet port or a 100 Mbps port. The cable category will not raise the device's own ceiling, but a Cat 6 cable ensures the cable is never the limiting factor.