OSI/TS Configuration and Management Manual
Glossary
OSI/TS Configuration and Management Manual—424831-001
Glossary-6
Header token.
Header token.  In an SPI message, a token that provides information pertaining to the 
message as a whole. Header tokens differ from other tokens in several ways: they exist 
in the buffer at initialization and their values are usually set by SSINIT, they can occur 
only once in a buffer, they are never enclosed in a list, they cannot be moved to another 
buffer with SSMOVE, and programs cannot position to them or retrieve their values 
using the NEXTCODE or NEXTTOKEN operation. Programs retrieve the values of 
header tokens by passing appropriate token codes to SSGET and can change the values 
of some header tokens by passing their token codes to SSPUT.
Examples of header tokens for commands are the command number, the object type, the 
maximum-response token, the server-version token, the maximum-field-version token, 
and the checksum token. Command and response messages contain a specified set of 
header tokens; event messages, a different set with some overlap. 
Indication primitive.  A primitive issued when a service user (entity) is to be informed 
about an event.  This is one of four types of service primitives. .
Indirect-process-name.  Form of a process name that directs the command through the OSI 
manager process first, then on to the specified process type, allowing the management 
information base (MIB) to be updated.
Initiator.  The entity that initiates a connect request. Initiators and responders are defined 
with respect to a single connection.  Some entities can be both an initiator and a 
responder simultaneously, but not over the same connection.
Intermediate system.  Any combination of subnetworks and relay systems used to connect 
two or more end systems. Compaq systems are not used as intermediate systems.
Invocation identifiers.  A pair of values identifying the application entity and application 
process at one end of an ACSE connection. Their settings are left up to the application.
IP (OSI internet protocol).  An ISO standard that defines communications in the Network 
Layer. This term is not to be confused with the internet protocol of TCP/IP, which is a 
different protocol.
IPPDU (IP protocol data unit).  See PDU (protocol data unit).
LAPB (link access protocol - balanced).  CCITT standards that define in the Data Link 
Layer the requirements for X.25 connections over wide area networks (WANs).
Layer.  There are seven layers in the OSI Reference Mode: Application Layer.
, Data Link 
Layer., Network Layer., Physical Layer., Presentation Layer., Session Layer., or 
Transport Layer.
LDIB (Local Directory Information Base).  See MIB (Management Information Base)..
LLC (logical link control).  An IEEE 802.2 standard for the Data Link Layer of the OSI 
Reference Model that defines both connection-oriented and connectionless standards 
over LAN networks.










