HP-UX iSCSI Software Initiator Support Guide, HP-UX 11i v1 and 11i v2, July 2005

Appendix F
Glossary
Terminology
120
Terminology
Directory Agent - A process which collects service advertisements. There can only be one DA present per
given host.
Discovery Session - Initiated with a Discovery Target to discover Operational Targets in a Network Entity.
Gigabit Ethernet - An ethernet infrastructure with the capability of transferring data at the rate of 1
gigabit per second in either the transmit or receive direction (abbreviated GigE).
iSCSI Adaptation Layer - A module which interfaces with the SCSI-2 services layer.
Interface Driver - A driver that interfaces to a host bus adapter or to another software subsystem that
controls a host bus adapter.
iSCSI Infrastructure - Components in a network supporting the iSCSI protocol that do not perform as
iSCSI targets or initiators; same as network infrastructure.
iSCSI Initiator - A network port with the capability of performing as a SCSI initiator as defined by SAM-2.
iSCSI Name - is permanent, globally unique, and location or address independent. Both targets and
initiators require names for the purpose of identification. In addition, names enable iSCSI storage resources
to be managed regardless of location (address). The iSCSI name is the principal object used in authentication
of targets to initiators and initiators to targets.
iSCSI Node - represents a single iSCSI initiator or iSCSI target. There are one or more iSCSI Nodes within
a Network Entity. The iSCSI Node is accessible via one or more Network Portals. An iSCSI Node is identified
by its iSCSI Name.
iSCSI Target - A network port with the capability of performing as a SCSI target as defined by SAM-2.
iSCSI Transport Layer - A session management module, which also interfaces with the iSCSI Adaptation
Layer and the interface driver.
Login Redirection - When an iSCSI login to a target is attempted, the target responds by redirecting the
login attempt to a different target address. Redirected addresses are provided as part of the login response to
the initial login attempt.
Network Entity - represents a device or gateway that is accessible from the IP network. A Network Entity
must have one or more Network Portals, each of which can be used by some iSCSI Nodes contained in that
Network Entity to gain access to the IP network.
Network Portal - a component of a Network Entity that has a TCP/IP network address and can be used by
an iSCSI Node within that Network Entity for it’s iSCSI session connection(s). In an initiator, the Network
Portal is identified by its IP address. In a target, the Network Portal is identified by its IP address and its
listening TCP port.
Normal Session - An unrestricted session used to transfer SCSI commands, data, and responses, between
an iSCSI initiator and an iSCSI Operational Target.
Persistent Storage - An area of storage where stored data will persist across power outages.
Portal Group - A Portal Group defines a set of Network Portals within an iSCSI Node that collectively
support the capability of coordinating a session with connections that span these portals.
Portal Group Tag - This 16-bit quantity identifies a Portal Group within an iSCSI Node. All Network
Portals in a given iSCSI Node that have the same portal group tag, are in the same Portal Group.
Service Agent - A process working on the behalf of one or more services to advertise the services.