11gR2 Grid Infrastructure Redundant Interconnect

any one can explain how this new feature works ?. as per the document from 11.2.0.2 Oracle GRID provide chance to allocate more private interconnect  to configure. in case of failure of inteconnect  private interconnect  will failover to alternate private interconnect .

but my question all this private interconnects will be configured by single cable at server level , if cable having  issue  what will be the use of above new feature.

also if any one having detailed oracle architecture diagram please share with me.

thanks

paramu