Jelaskan Knockout Round dari Liga Champions AFC 2007

All 8 clubs are randomly matched; however, the only restriction is that the clubs from same country cannot face each other in the quarterfinals. The games are conduced in 2 legs, home and away, and the aggregates goals decides the match winner. If the aggregate goals cannot produce an winner, away goal rules in used. If still tied, clubs play extra time, where away goal rule still applies. If stilled tied, the game goes to penalties.