Heat oven to 350 degrees. Trim skin and excess fat off ham. With sharp knife, score ham all over in diamond pattern.
Place ham in a large Anolon roasting pan, then pour 1 cup cola and 1 cup orange juice over it. Cover pan with aluminum foil and roast for 75 minutes.
While ham roasts, in medium saucepan, combine remaining cola, orange juice, brown sugar and Dijon mustard. Bring mixture to boil over medium-high heat and cook about 45-48 minutes, until reduced to 1 cup and mixture is slightly syrupy.
After ham roasts, remove foil and baste with glaze. Continue roasting and basting ham every 15 minutes with glaze until it is glossy and instant read thermometer inserted into thickest portion registers 145 degrees, about 75-90 minutes longer.
Remove from oven and let rest 15-20 minutes before slicing.