ICL cabling configurations

The following figures show acceptable cabling configurations for the inter-chassis link (ICL) feature between QSFP ports in core routing blades. The recommended topology is the parallel type where at least four QSFP cables connect between both core routing blades on any two directors. This provides ICL trunking between directors, ensuring redundancy. Parallel connections between core blades are recommended.

Following are the maximum numbers of directors that you can connect using 4x32-Gbps quad SFP (QSFP) inter-chassis links (ICLs):

• Up to nine Gen 6 directors can be connected in a full-mesh topology.
• Up to six directors are recommended in a full-mesh topology if connecting a mixture of Gen 6 and Gen 5 directors.
• Up to 12 directors can be connected in a core-to-edge topology.

Figure 1. ICL cable connections for SAN256B-6 and SAN512B-6 Director (sample configuration)

1. Chassis 1 - SAN512B-6
2. Chassis 2 - SAN256B-6

To connect multiple SAN256B-6 and SAN512B-6 Directors via ICLs, a minimum of four ICL ports (two on each core routing blade) must be connected between each chassis. The dual connections on each core blade must reside within the same trunk group. If more than four ICL connections are required between a pair of directors, additional ICL connections should be added in pairs (one on each core blade). ISLs and ICLs can co-exist between the same pair of directors if the ISLs and ICLs are on different logical switches.

The SAN256B-6 or SAN512B-6 Director can be connected in a core-edge configuration. The following figure shows two core and four edge devices. Although SAN512B-6 Directors are shown in the figure, the device can be either SAN256B-6 or SAN512B-6 Directors. 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 2. IBM SAN Director core-edge ICL topology

SAN256B-6, SAN512B-6, SAN384B-2 and SAN768B-2 Directors can also be connected in a full-mesh configuration.