Network plugs, couplers and accessories

RJ45 plug — how to match it to the cable

An RJ45 (8P8C) plug is crimped onto the end of a twisted-pair cable with a crimping tool. The plug category should match the cable category:

• Cat5e UTP plugs — for 1 Gbps home installations on Cat5e cable.
• Cat6 UTP plugs — for the thicker conductors of Cat6 cable, including installation cable from a reel.
• Cat7 FTP plugs — shielded, with a metal housing, for shielded cables.

Plugs are sold in multi-packs. Before you buy, check on the product page whether the plug is designed for solid or stranded cable.

Shielded or unshielded plug

FTP plugs have a metal housing that connects to the cable's shield. They are only used with shielded cable, such as Cat7 — on standard UTP cable the housing does nothing, and the plug is bulkier and harder to crimp. For UTP cable, lightweight plastic plugs are enough.

T568A or T568B standard

When terminating a plug, the wire order matters. The most widely used is the T568B standard: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown. The key is that both ends of the cable and the wall socket are wired to the same standard — then the patch cable will work with any device.

RJ45 coupler and ethernet wall socket

An RJ45 coupler joins two terminated cables into one longer cable, with no cutting or re-crimping. It is useful when the cable to your console or TV turns out to be too short. Couplers are available singly and in sets, including Cat7 versions. A wall-mounted RJ45 socket, either single or dual with RJ11, terminates cabling run through a wall or trunking and lets you connect equipment with a short patch cable. The version with an extra RJ11 socket is handy when a phone line or DSL internet needs to reach the same spot.

You will find ready-made cables in the Cat5 and Cat6 ethernet cables and Cat7 ethernet cables categories, and RJ45 adapters for laptops in the network adapters and cards section. The full range is in the Ethernet category.

Frequently asked questions

Does an RJ45 coupler slow down the internet?

A good-quality coupler on a home network does not reduce speed. Each extra connection is, however, another point where a loose contact can develop, so for a permanent installation it is better to run a single cable.

How do I terminate an RJ45 plug?

Strip about 2 cm of the outer jacket, untwist the pairs and arrange the wires in T568B order. Trim them evenly, push them into the plug all the way to the front and crimp with a crimping tool. Finally, test the connection with a cable tester or by plugging the cable into your router.