WAN Manager SPI Programming Guide

WAN Manager SPI Programming Guide—540013-001
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1 Introduction
SPI, a central component of the Distributed System Management (DSM) architecture,
is the path that management applications and subsystems use to exchange
command-response messages and event messages. Communication between a
management application and a subsystem follows the standard HP NonStop requester-
server model, with the management application in the role of requester and the
subsystem manager process in the role of server. Commands are sent as SPI
messages in the SPI command buffer and the responses are returned as SPI
messages in the SPI response buffer.
Figure 1-1 illustrates the interaction between the management application (for
example, SCF, TSM (G-series RVUs only), or OSM) and the WAN manager through
the SPI interface.
An SPI command buffer and a response buffer each consist of a common header and
variable body tokens. A header is a collection of header tokens that are the same for
both the command buffer and the response buffer.
The header always contains a command token, ZSPI-TKN-COMMAND, that specifies
the command and an object-type token, ZSPI-TKN-OBJECT-TYPE, that specifies the
object type on which the command is carried out.
The response buffer is a group of tokens containing all the information that results
when you run a command. The response buffer always contains a return token,
ZSPI-TKN-RETCODE. If a command fails, this token contains an error number
indicating the reason for the failure. This error number is defined by the WAN
subsystem.
Figure 1-1. Communication Between the Management Application and WAN
Manager
Header
WAN
Manager
Management
Application
Header Tokens...
SPI Command Buffer
SPI Response Buffer
Tokens...
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