Connectivity-Splitting Models for Survivable Network Design * Anantaram Balakrishnan Smeal College of Business Penn State University University Park, PA Thomas L. Magnanti School of Engineering Massachusetts Institute of Technology Cambridge, MA Prakash Mirchandani Katz Graduate School of Business University of Pittsburgh Pittsburgh, PA January 2002 * Supported in part by NSF grants DMII-0115304 and DMII-0115434