Cabling behind ATTO bridge can be traced. Here is example of (7-Mode/node shell) storage bridge and environment shelf output:
storage bridge:
SAS Port A:
QSFP Vendor: Molex Inc.
QSFP Part Number: 112-00177+A0
QSFP Type: Passive Copper 2m ID:01
QSFP Serial Number: 417721061
environment shelf:
SAS cable information by element:
[1] Vendor: Molex Inc.
Type: QSFP passive copper 2m ID: 00 Swaps: 0
Serial number: 417721061 Part number: 112-00177+A0
Just follow serial numbers. Shelf port numbers are documented in SAS adapter connected to misconfigured SAS domain