Brackets for cable management. Redundant bus interface card connections. All line cards and modules can be hot-swapped. Blower modules can be replaced without interrupting service, within certain time limits. Two central slots are reserved for PRE cards Eight slots accommodate full-height line cards.
All cards support hot-swapping and redundancy.
Note One PRE is required for the system to operate, so hot-swapping a nonredundant PRE results in a system outage. A secondary PRE in a redundant configuration can be hot-swapped with no effect on system operation. Figure 2-1 shows a fully loaded Cisco 10008 chassis with redundant PREs, PEMs, and various line cards. The Cisco backplane design improves on communications devices that are based on a shared system bus. Buses with several loads often suffer electrical reflections and signal degradation that cannot be corrected by improved semiconductor technology.