The User's Guide that came with your hardware should have a Chapter or two dedicated to Lights Out Management. For example if you go to: http://sunsolve.Sun.COM/handbook_pub/Systems/Netra_T1_AC200/docs.html
You will see the Users Guide (PDF) for the Netra T1 AC200. Chapters 8 & 9 go into LOM fairly extensively.
For you particular system go to: http://sunsolve.Sun.COM/pub-cgi/show.pl?target=home
and at the bottom, in the Sun System Handbook section, click on Telco Systems, the click on your particular server in the right column. Then click on Related Documentation in the Information Area box to see what documentation is available for your server.