IOM modules are also known as Cisco FEXs or simply FEX modules. These modules serve as line cards to the FIs in the same way that Nexus series switches can have remote line cards. IOM modules also provide interface connections to blade servers. They multiplex data from blade servers and provide this data to FIs and do the same in the reverse direction as well. In production environments, IOM modules are always used in pairs to provide redundancy and failover.
Apart from data transfers between chassis and FIs, IOM modules provide the following two features:
Chassis Management Controller (CMC): This monitors chassis components such as fan units, power supplies, and chassis temperature. This also reads chassis component identification data and detects the insertion and removal of blade servers.
Chassis Management Switch (CMS): This provides fast Ethernet links to the embedded Cisco Integrated Management Controller (CIMC) on blade servers for Keyboard Video Mouse (KVM) access and S erial over LAN (SoL) access and for Intelligent Platform Management Interface (IPMI) data to travel from individual blades to FIs for monitoring and management purposes.
The following figure depicts components and connectivity inside an IOM module:
The specifications of the Cisco 2208XP IOM card are as follows:
Eight 10 Gbps fabric ports for connecting to the FI
32 10 Gbps, server-facing ports with FCoE
80 Gbps throughput
