Open System Services Management and Operations Guide (G06.29+, H06.07+)

Introducing Open System Services
Open System Services Management and Operations Guide—527191-005
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Interprocess Communication Facilities
The application processes (Processes 1 through 4) communicate with each other
through the transport-provider ($ZTCn) processes, with data being carried back
and forth by the transport-agent processes. Transport-agent processes do not
communicate with each other directly, but through the transport-provider.
Figure 1-6. OSS AF_INET Sockets Servers for NonStop TCP/IP
Note. Whenever any application process sends a message to another process, the
message is always sent through the transport-provider processes and through the
network, regardless of which processors or nodes they are running on. Even when two
processes are running on the same processor, a message from one to the other always
goes to the transport-provider process first.
Process 1
$ZTA00
$ZTC0
Process 2
$ZTA01
Node A
Node B
Processor 0
$ZTC0
$ZTA00
Process 3
Processor 1
$ZTC1
$ZTA01
Process 4
VST012.VSD
Processor 0 Processor 1