The flamboyant Porter decided to join the Dolphins despite also drawing interest from the Cincinnati Bengals.
The deal reportedly is for five years and $32 million, with $20 million in guaranteed money. Remember, Porter was scheduled to make $5.3 million with the Steelers in 2007 before being released last week.
The addition of Porter fills a major need at outside linebacker. It also follows the signing of Green Bay tight end David Martin as an unrestricted free agent.
The signing of Martin came on the same day the Dolphins also announced they had terminated the contracts of Randy McMichael and Joey Harrington, and traded wide receiver Wes Welker to New England for second- and seventh-round picks in the 2007 draft.