In a 3- to 4-quart pan over medium-high heat, stir together cranberries, orange peel, orange juice, and sugar. Bring mixture to a boil, then lower the heat to maintain a simmer, and cook, stirring frequently, until the berries have broken open and released their juices, 8 to 10 minutes. Add Port and cook 2 minutes longer. Let cool completely and store airtight up to 2 weeks.
Nutritional analysis per tablespoon.