The former Tottenham trainee has a wealth of experienced having played for a number of Football League clubs in a career spanning nine years.
"Mark is a great signing for us," Boro chairman Phil Wallace told the club's official website.
"If there was one thing we possibly lacked at times last season, it was experience at the back.
"Mark has made over 400 appearances with Barnet, Oldham and Peterborough and over 100 of them have been for Peterborough in the last two and a half seasons.
"He's therefore been pretty much an ever present under a few different managers, which is always a sign of a players importance to a team.
"The search is now focused on a quality striker to add to the squad."
Source: http://www.confguide.com/newsArticle.do?id=6729