The extensions should already be set on the base, from the initial setup (as above).
To pair the handsets :
- Go to the handset settings (cog button bottom right), then select Registration - don't press Register Handset yet
- Hold down the central blue button on the base for a few seconds and now press Register Handset on the handset
- The handset will display Searching for base in Registration mode
- The handset will then prompt Please enter system PIN - let go of the middle button on the base at this point, and enter 0000
The handset should now be paired. To check that the pairing is successful, quickly tap the middle button of the base - this will page associated paired handsets with a valid chorus IP address 10.xx.xx.xx. If it doesn't then please try to re-pair the device. For further help, please see the troubleshooting section below.
(The IP address can also be found at Settings > System > Local network)