In large bowl, combine fish sauce, sugar, salt, pepper, garlic, cilantro and water. Place ribs in a bowl and pour marinade on top. Marinate for 12 hours. Prepare fire. Place ribs on grill and grill for 45 minutes, turning frequently. In small saucepan, combine sugar, vinegar, salt, and garlic. Bring to a boil and reduce heat to a simmer. Cook until thick about 5 minutes. Finely grate bell pepper and add to sauce for color. Serve.