ALAMEDA (AP) — The Oakland Raiders added two more playoff-tested veterans to their rebuilding defense.Oakland signed free agent defensive lineman Antonio Smith to a two-year, $9 million contract and cornerback Tarell Brown to a one-year, $3.5 million deal Friday.The moves come a day after Oakland signed Justin Tuck and LaMarr Woodley to two-year deals to bolster the defensive line, giving Oakland four new defensive starters with experience of playing in the Super Bowl.“I think it’s a domino effect,” Brown said. “I think anytime you bring in guys that have won a lot of games and have played in a lot of big games as well and have had a lot of success in this league, it definitely helps. We can kind of put things in perspective and guide younger guys in the direction of saying, ‘Look, get under my wing and this is how you do it in the NFL to be successful.’”Oakland needs plenty of help on defense after showing promise early last season.