ICL Cabling Configurations

The following figures show acceptable cabling configurations for the ICL feature between OSFP ports in ICL blades.

The recommended topology is the parallel type where at least two OSFP cables connect between both ICL blades on any two directors. This topology provides ICL trunking between directors, ensuring redundancy.

Following are the maximum numbers of directors that you can connect using Gen 8 OSFPs:

  • Up to nine IBM SAN512B-8 directors can be connected in a full-mesh topology.
  • Up to 12 directors can be connected in a core-edge topology.

To connect multiple IBM SAN512B-8 directors through ICLs, a minimum of two OSFP ports (one on each ICL blade) must be connected between each chassis. The dual connections on the two ICL blades must reside within the same trunk group. If more than two OSFP connections are required between a pair of directors, additional OSFP connections should be added in pairs (one on each ICL blade). ISLs and ICLs can co-exist between the same pair of directors if the ISLs and ICLs are on different logical switches.

The following illustration shows the minimum connectivity between a pair of X8 chassis:
Figure 1. ICL Cable Connections between Two IBM SAN512B-8 Directors
The following illustration shows the minimum connectivity between an IBM SAN512B-8 and X8-4 chassis:
Figure 2. ICL Cable Connections between an IBM SAN512B-8 Director and an X8-4 Director (Sample Configuration)

The following requirements apply for ICLs between X8 chassis:

  • A minimum of two OSFP ports (one on each ICL blade) must be connected between each chassis pair.
  • The dual connections on each ICL blade must reside within the same ICL trunk boundary on the ICL blades.
  • If more than two OSFP connections are required between a pair of chassis, additional OSFP connections should be added in pairs, with each additional pair residing within the same trunk boundary.
  • OSFP-based ICLs and traditional ISLs are not concurrently supported between any pair of chassis.

The following figure show acceptable cabling configurations for the ICL feature between OSFP ports in X8 ICL blades and QSFP ports in X7 CR blades.

This illustration shows the minimum connectivity between an X8 and an X7 chassis:
Figure 3. ICL Cable Connections between an IBM SAN512B-8 Director and an X7-8 Director (Sample Configuration)

The following requirements apply for configuring ICLs between an X8 chassis and an X7 chassis:

  • An OSFP-to-QSFP breakout cable must be used to connect one Gen 8 OSFP on the Gen 8 chassis to two QSFPs on the same Gen 7 chassis.
  • The QSFP breakout connectors (A and B) must connect to the same QSFP port numbers on separate CR blades on the same X7 chassis.
  • A minimum of two Gen 8 OSFP ports (one on each ICL blade) must be connected between each chassis pair.
  • The dual connections on each ICL blade must reside within the same ICL trunk boundary on the ICL blades.
  • If more than four OSFP connections are required between a pair of chassis, additional OSFP connections should be added in pairs, with each additional pair residing within the same trunk boundary.
The following figure shows two core devices and four edge devices. The cabling scheme should follow the parallel example shown in the previous figure. Each line in the example actually represents four cables running between the devices.
Figure 4. Director Core-Edge ICL Topology

For details on the following subjects, refer to the "Inter-Chassis Links" section of the Brocade Fabric OS Administration Guide:

  • ICL topologies
  • ICL trunking
  • Configuring ICLs between IBM SAN512B-8 directors
  • Configuring ICLs between IBM SAN512B-8 directors and X7 Directors