assis-based switch is called a supervisor. Supervisors are also commonly referred to as sups (pronounced like "soups"). Over the years, different supervisor models have been introduced to offer greater speed and versatility. Increased functionality has also been made available via add-on daugh- ter cards, which are built into the later supervisor models. Supervisors offer Layer-2 processing capabilities, while an add-on daughter card- called a multilayer switch feature card-supports Layer-3 and higher functionality. Supervisor models 1 and 2 offer the MSFC as an add-on, while later models include the MSFC as an integral part of the supervisor. When you're running hybrid-mode IOS on the 6500 chassis, the MSFC is considered a separate device regardless of the supervisor model. In CiscoView, the MSFC appears as a small router icon to the left of the supervisor, where the fan tray resides. Fig- ure 17-4 shows the CiscoView representation of a Supervisor-720 with the MSFC on the left. Different versions of the MSFC are referenced as MSFC1, MSFC2, and MSFC3. The MSFC2 is paired with the Supervisor-2, while the MSFC3 is part of the Supervisor-720. The policy feature card (PFC) is a daughter card that supports QoS functions in hard- ware, drastically improving performance where QoS is needed. No direct configuration of the PFC is required. The three generations of the PFC are named PFC1, PFC2, and Chapter 17: Cisco 6500 Multilayer Switches PFC3. The PFC2 is paired with the Supervisor-2, and the PFC3 is an integral part of the Supervisor-720. COMSEIN PRINT THEET CANSULE SIGER TMV-1 STATUS Figure 17-4. Cisco View representation of Supervisor-720 and MSFC Models Supervisor models most commonly seen today include: Supervisor-1A This is the slowest and oldest of the supervisor modules, capable of supporting 32 Gbps and 15 Mpps (the Supervisor-1A replaced the original Supervisor Engine, also called the Supervisor-1) The Supervisor-1A is end-of-life but may still be seen in older installations. When coupled with a PFC and an MS