2-way switching: wiring the strapper cable

2-way switching lets two switches each control the same light — ideal for top and bottom of stairs, or either end of a corridor. Here's what's already wired (shown in grey): • The mains supply (feed) connects to the ceiling rose. • The pendant connects the rose to the lamp. • Switch drop 1 carries permanent live (line) from the rose's L terminal down to switch 1's COM terminal. • Switch return 2 carries switched live from switch 2's COM terminal back up to the rose's Sw terminal. Your job: wire the 3-core strapper cable between the two 2-way switches. The strapper connects L1↔L1 and L2↔L2 between the switches. Whichever strapper core is selected by both switches at the same time forms the live path that illuminates the lamp. Note: a 2-way switch has three terminals — COM (common), L1, and L2. This is different from a 2-gang switch, which is simply two 1-way switches on one faceplate.