Oculink cable manufacturers talk about the SAS connection guidelines

Note the following guidelines when connecting cables to SAS ports in a 2U expansion enclosure.
1. the number of display cabinets connected to SAS port 1 of the node container cannot exceed 10. Expansion enclosures in the chain should be installed below the control enclosure.
Storwize@ V5030 and Storwize V5030F systems only.
You cannot have more than 10 expansion enclosures linked to SAS port 2 of the node canister. Expansion enclosures in the chain should be installed above the control enclosure.
2. When connecting an odd number of expansions to a control enclosure, ensure that the SAS expansion chain connected to SAS port 1 of the canister contains 1 more expansion enclosure than the SAS expansion chain connected to SAS port 2 of the canister.
3. No cables can be connected between the port on the left canister and the port on the right canister.
4. Cables should not be connected between ports in the same-cabinet.
5. The connected port on the node canister must be connected to a single port on the extension canister. Branching uses a split cable with multiple physical connections.
6. Serially connect cables between cabinets; do not skip a cabinet.
7. The last cabinet in the chain cannot be wired to port 2 on container 1. and port 2 on container 2.
8. Ensure that cables are installed in an orderly manner to reduce the risk of damage to cables when removing or inserting a replaceable unit.