ots are allocated the same way, with the obvious difference that there are no slots 7, 8, and 9; the 6513-chassis slots are allocated similarly, though Sup-720s must reside in slots 7 and 8 instead of 5 and 6. The additional slots (10-13) can house any line card or service module apart from supervisors or SFMs. These last four slots in the 6513 chassis cannot support certain fabric-only blades. Consult the Cisco documentation for specifics when ordering cards for this chassis. Enhanced Chassis A series of enhanced 6500 chassis, identified by an e at the end of the chassis part number, is also available. An example of an enhanced chassis is the 6500e. The en- hanced chassis are designed to allow more power to be drawn to the line cards. The advent of Power over Ethernet (PoE) line cards for VoIP applications was one of the key drivers for this evolution. The enhanced chassis use high-speed fans to cool these power-hungry modules. The e-series chassis also provide a redesigned backplane that allows for a total of 80 Gbps of throughput per slot. This represents a theoretical doubling of the capacity of Architecture the standard 6500 chassis (40 Gbps of throughput per slot), though at the time of this writing, there are no line cards or supervisors that support this speed. The new archi- tecture will allow eight 10 Gbps ports per blade with no oversubscription. Cisco now only produces the enhanced chassis models, though the standard chassis models are still available though the secondhand market. Vertical Enhanced Chassis A special version of the enhanced 6500 chassis is now available. This chassis, named the 6509-V-E, supports 80 Gbps per slot and includes features previously found on the NEBS chassis. Features of this chassis include front-to-back airflow and vertical module orientation. Supervisors Chassis-based switches do not have processors built into them like smaller switches do. Instead, the processor is on a module, which allows the hardware to be swapped and upgraded with ease. The processor for a Cisco ch