Open System Services Management and Operations Guide (G06.27+, H06.04+)
Introducing Open System Services
Open System Services Management and Operations Guide—527191-003
1-16
Interprocess Communication Facilities
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Multiple transport-provider processes can be used to create separately addressed 
IP subnetworks within a node
When AF_INET sockets are used with NonStop Parallel Library TCP/IP:
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No transport-agent process or transport-provider process is involved in data 
routing.
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A transport-agent process must still be started in each processor to initialize the 
OSS sockets interface for that processor.
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One transport-provider process must be running in the system. The transport-
provider process provides configuration compatibility for open and close operations 
on sockets and for nonsensitive SCF commands.
When AF_INET sockets or AF_INET6 sockets are used with NonStop TCP/IPv6:
•
No transport-agent process or transport-provider process is involved in data 
routing.
•
A transport-agent process must still be started in each processor to initialize the 
OSS sockets interface for that processor.
•
At least one transport-provider process must be running in the system.
•
The transport-provider process provides configuration compatibility for open and 
close operations on sockets and for nonsensitive SCF commands.
•
Multiple transport-provider processes can be used to create separately addressed 
IP subnetworks within a node. This feature is called logical network partitioning; 
such subnetworks are configured and controlled through the SCF interface for the 
NonStop TCP/IPv6 subsystem.
Transport-Agent Processes:
•
The transport-agent process initializes global sockets structures and tables when it 
starts. A transport-agent process that routes data (for NonStop TCP/IP or AF_UNIX 
sockets) among OSS sockets application processes does so for a single 
processor. Each processor has its own copy of the transport-agent process.
•
HP provides a transport-agent process, $ZTAnn, where nn is the processor 
number. The transport-agent process starts automatically when the processor 
comes up. You can bring down its processor without first stopping the process, but 
you should stop all applications with open OSS sockets before bringing down a 
processor. You manage the transport agent through the SCF module of the OSS 
Monitor, as described in Section 4, Managing Servers.
Transport-Provider Processes:
•
A transport-provider process provides routing services for one sockets address 
family. Each node has one or more transport-provider processes.










