How to play xbox live on halo 3?

[Jonah T]

I just got a xbox 360 like 2 weeks ago and my first game is halo 3. The problem is that when i try to go on xbox live with halo 3 I don't know how to get on it like I can invite people to play with that are in my friends list or people I have played with before but I can't search rooms and join them like in Ghost Recon 2. Is there a way to do that or can you only play with you friends online?

 

[ispip]

you go to matchmaking to play with your friends
and on the playlist?.. are the games you can choose
but you can join specific rooms were bunch of people are ...etc. unless you play custom games ...which you can only play with friends or others that you invite

 

[wat up]

change filters i think?