The 28-year-old made 25 appearances during a loan spell with Birmingham City last season.
"He'll bring a bit of height, a bit of strength and experience," Jewell told BBC Radio Suffolk. "He's a good player.
"[Former Birmingham manager] Chris Hughton speaks very highly of him and we were pleased he wasn't playing against us [last season]. He was at the African Nations and he was injured when we played here."
N'Daw has won 39 caps for his country.