Requirements for Shared ISL configurations
The ISL carries host-to-node, inter-node traffic, and other LAN traffic across the sites. All the traffic types are mixed and shared over the same ISL in the shared ISL.
Sharing ISL with multiple traffic types can create performance issues or disrupt system operation. To mitigate such issues, a network administrator can guarantee certain quality checks for each traffic type. An administrator can set up PFC (Priority-based Flow Control) values and assign them to the appropriate traffic type, which helps prioritize traffic types and achieve better performance. In shared ISL connectivity, the hosts and SVC nodes are connected at the same site through local switches. Thus, the hosts that are connected to storage with local network infrastructure are partitioned into two sites. For example, in Figure 1, local infrastructure is partitioned in Failure domains 1 and 2 sites. The switches present in each site are connected with each other over shared ISLs. Each control enclosure has connectivity to the IP quorum application by using management ports. You can also add external storage, and that can be locally accessed to each site, as seen in the same figure.
