The Catalyst 4500 Series includes four chassis: Catalyst 4510R (10-slot: redundant Supervisor Engine capable), Catalyst 4507R (7-slot: redundant Supervisor Engine capable, Catalyst 4506 (6-slot), and Catalyst 4503 (3-slot). A primary component of Cisco AVVID (Architecture for Voice, Video and Integrated Data), the Catalyst 4500 Series extends control to enterprise wiring closets, branch offices, and Layer 3 distribution points.