Network connectivity is provided by a pair of Cisco UCS 9108 Intelligent Fabric Modules (IFMs). Similar to the fabric extenders used in the Cisco UCS 5108 Blade Server Chassis, these modules carry all network traffic to a pair of Cisco UCS 6400 series or Cisco UCS 6536 Fabric Interconnects (FIs). Having a single point of network connectivity and control in a system provides deterministic latency. This, in turn, frees you to place workloads without regard to whether the compute nodes are in the same chassis. Each IFM features the following:

Cisco UCS 9108-25G-D IFM:

• Server ports: Up to 50 Gbps of unified fabric connectivity per compute node with two IFMs.
• Uplink ports: 8x 25-Gbps SFP28 ports.

The unified fabric carries management, application data traffic using Ethernet and/or Fibre Channel over FCoE protocols to the fabric interconnects. There, management traffic connects to the Cisco Intersight cloud operations platform; FCoE traffic is passed to native Fibre Channel interfaces through universal ports on the fabric interconnects, and production Ethernet traffic is passed upstream to the data center network.

Up to two Intelligent Fabric Modules (IFMs) plug into the back of the UCS X9508 chassis.

The IFMs serve as line cards in the chassis and multiplex data from the Cisco UCS X210c or X410c compute nodes to the Fabric Interconnect (FI). They also monitor and manage chassis components such as fan units, power supplies, environmental data, LED status panel, and other chassis resources. The compute node’s Keyboard-Video-Mouse (KVM) data, Serial over LAN (SoL) data, and Intelligent Platform Management Interface (IPMI) data also travel to the IFMs for monitoring and management purposes. In order to provide redundancy and failover, the IFMs are always used in pairs.

There are 8 X QSFP28 connectors on an IFM to interface with a Fabric Interconnect (FI). The IFM provides up to 8X 25 Gbit/s links for the UCS 9108-25G IFM. The links provide the end-to-end interface from a compute node in the X9508 chassis to the connections on a Fabric Interconnect (FI). When a compute node is inserted into the chassis, the compute node’s upper mezzanine card (mLOM) plugs directly into the two IFMs using two orthogonal connectors (ODs). The X9508 chassis accommodates either two Cisco UCS 9108-25G IFMs, two Cisco UCS 9108-100G IFM, or Cisco UCS Fabric Interconnect 9108 100G.