OSI/MHS Configuration and Management Manual

Introduction to OSI/MHS
OSI/MHS Configuration and Management Manual—424827-003
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OSI/MHS Interface to OSI/AS
Figure 1-12 shows a GI group.
A GI group contains the gateway interface (GI) process and a PDU store.
An OSI/MHS subsystem can have zero, one, or more GI groups.
Gateway Interface (GI) Process
The GI process is a single, restartable process that provides an interface between a
general user gateway (a GPI application) and the parts of OSI/MHS that provide the
MTA function.
GI PDU Store
Each GI group shares an MR PDU store with an MR process. The PDU store consists
of a data file and a log file. Although a GI PDU store is defined for each GI group, it is
not currently used: it is defined for possible future use.
OSI/MHS Interface to OSI/AS
An OSI/MHS subsystem communicates with adjacent MTAs and remote UAs through
OSI services. Access to these services is provided to OSI/MHS through the use of
OSI/AS, which implements the OSI Reference Model Layer 5 through Layer 7. OSI/AS
uses the OSI lower layer services provided by OSI/TS and the network service
provider (NSP): X25AM for wide area networks (WANs), TLAM for local area networks
Figure 1-12. Gateway Interface (GI) Group
038VST .VSD
OSI/MHS Subsystem
GI Group
GI PDU
Store
GPI
GI
MR Groups
MS Groups
MR PDU
Store