Connect the line brown wire coming from the light together with the 3 coreearth cable black wire in to the l1 terminal of the two way switch. This cable consists of three cores brown grey and black which are all line colours and an earth wire.

2 Way Switching Diywiki
Wiring a landing light switch. This is very useful in a number places particularly hallways and stairs. The red and black are used for hot and the white neutral wire at the switch box allows for powering a timer remote control or other programmable switch. For wiring a two way switch 3 coreearth cable is used. I have a problem with my hall and landing lighting. Although the principle of light switch wiring is fairly basic things can sometimes get confusing when the switch is in the middle of a circuit or it controls more than one light and there are multiple wires in the electrical box. Power off and test each cable by switch light switch until cables to switch are found.
Two way switching allows you to control a light from two locations. A two way switch has 3 terminals. 2 way switching means having two or more switches in different locations to control one lampthey are wired so that operation of either switch will control the light. The downstairs light has two sets of wires supplying power to the switches each wire carries one red and one black wire. Connect the blue wire with the brown. This is an updated version of the first arrangement.
The light fitting has two gangs labelled l at the top and l1 bottom left l2 bottom right. If the switch wont turn off the lights its probably because you bypassed it somehow. Instead of using com to l1 for switch wires you use l1 and l2 and the two switches are connected together like for like. Wiring a two way switch. A commonc l1 and l2. Because the electrical code as of the 2011 nec update requires a neutral wire in most new switch boxes a 3 wire cable runs between the light and switch.
Com to com l1 to l1 and l2 to l2. Downstairs is a two switch light fitting upstairs landing is a one switch fitting. To switch from two locations youll need 2 two way switches and wire them together in a particular way. Two way switching is between switches the wiring to lamps stays the same. This arrangement is often found in stairways with one switch upstairs and one switch downstairs or in long hallways with a switch at either end.