Patent ID: RE39116

Claim:
In a network having at least a first data source/sink and a second data source/sink coupled together by a physical medium, apparatus for determining at least one protocol capability of said second data source/sink, comprising: first means, coupled to said first source/sink, for placing a first signal onto said physical medium, said first signal indicating a first protocol capability of said first source/sink; second means, coupled to said second data source/sink, for receiving said first signal, third means, coupled to said second data source/sink, for transmitting a second signal onto said physical medium when said second data source/sink has said first protocol capability, said second signal comprising a plurality of pulses spaced-apart by a first time interval, and a third signal, different from said second signal, when said second data source/sink has a second protocol capability, said third signal comprising a plurality of pulses spaced-apart by a second time interval, different from said first time interval; fourth means, coupled to said first data source/sink, for detecting whether said signal transmitted by said second means is said second signal or said third signal, and fifth means, coupled to said first data source/sink, for establishing communication with said second data source/sink using said first protocol if said fourth means detects said second signal and using said second protocol if said fourth means detects said third signal.