Seagate SCSI Interface Product Manual page 20

6 SCSI Interface Product Manual, Rev. J
physical interconnect—A single physical pathway for the transfer of information between SCSI devices in a
domain.
port—Synonymous with "service delivery port." A single attachment to a SCSI bus from a SCSI device.
procedure—An operation that can be invoked through an external calling interface.
protocol—The rules governing the content and exchange of information passed between distributed objects
through the service delivery subsystem.
protocol option—An option whose definition within a SCSI-3 protocol standard is discretionary.
protocol service confirmation—A signal from the lower level protocol service layer notifying the upper layer
that a protocol service request has completed.
protocol service indication—A signal from the lower level protocol service layer notifying the upper level that
a protocol transaction has occurred.
protocol service request—A call to the lower level protocol service layer to begin a protocol service transac-
tion.
protocol service response—A reply from the upper level protocol layer in response to a protocol service indi-
cation.
queue—The arrangement of tasks within a task set, usually according to the temporal order in which they were
created. See task set.
queue tag—The parameter associated with a task that uniquely identifies it from other tagged tasks for a logi-
cal unit from the same initiator.
receiver—A client or server that is the recipient of a service delivery transaction.
reference model—A standard model used to specify system requirements in an implementation-independent
manner.
request—A transaction invoking a service.
request-response transaction—An interaction between a pair of distributed, cooperating objects, consisting
of a request for service submitted to an object followed by a response conveying the result.
request-confirmation transaction—An interaction between a pair of cooperating objects, consisting of a
request for service submitted to an object followed by a response for the object confirming request completion.
reset event—A protocol-specific event which may trigger a hard reset response from a SCSI device as
described in Section 4.6.6.
response—A transaction conveying the result of a request.
SCSI application layer—The protocols and procedures that implement or invoke SCSI commands and task
management functions by using services provided by a SCSI protocol layer.
SCSI device—A device that is connected to a service delivery subsystem and supports a SCSI application
protocol.
SCSI device identifier—An address by which a SCSI device is referenced within a domain.
SCSI I/O system—An I/O system, consisting of two or more SCSI devices, a SCSI interconnect and a SCSI
protocol, which collectively interact to perform SCSI I/O operations.
SCSI protocol layer—The protocol and services used by a SCSI application layer to transport data represent-
ing a SCSI application protocol transaction.
sender—A client or server that originates a service delivery transaction.
server—A SCSI object that performs a service on behalf of a client.
service—Any operation or function performed by a SCSI-3 object, which can be invoked by other SCSI-3
objects.
service delivery failure—Any non-recoverable error causing the corruption or loss of one or more service
delivery transactions while in transit.