Sennheiser Avaya 1400,1600, 2400, & 9000 series EHS set up (cat 2083)
1) Plug the cord with the green sticker into the PHONE port in the back of the headset base
2) Plug the cord with the pink sticker into the ACC port in the back of the headset base.
3) Plug the other end of the EHS into the HEADSET jack of the phone
4) Plug the ring detector into the box in the middle of the EHS. Stick the mic over the speaker of the phone
5) Set compat to A and move dipswitch #1 down (in the bottom right in back of cube)