Products are necessary to comply with a protocol so which the interrupt-request (IRQ) traces is usually shared. The PCI bus incorporates 4 interrupt lines, INTA# by way of INTD#, all of which are offered to each system. Nearly eight PCI units share exactly the same IRQ line (INTINA# by INTINH#) https://nathanlabsadvisory.com/how-nist-800-171-compliance-consulting-in-usa-can-secure-your-business-data/