The Bose link input on the back of the media centre is used for connecting the 3∙2∙1 system to a Bose Lifestyle® system in another room. This proprietary technology makes it possible to play audio streams from a Lifestyle® system on compatible Bose products (such as your 3∙2∙1 system) in other areas of the home.
Using your system's Bose® link input with a Bose Lifestyle® system