NonStop Operations Guide for H-Series and J-Series RVUs

7 Communications Subsystems: Monitoring and Recovery
• “When to Use This Chapter” (page 85)
• “Communications Subsystems” (page 85)
“Local Area Networks (LANs) and Wide Area Networks (WANs)” (page 85)◦
◦ “CLuster I/O Modules (CLIMs)” (page 87)
“Monitoring Communications Subsystems and Their Objects” (page 88)
• “Monitoring the SLSA Subsystem” (page 88)
• “Monitoring the WAN Subsystem” (page 90)
• “Monitoring the NonStop TCP/IP Subsystem” (page 93)
• “Monitoring the CIP Subsystem” (page 94)
• “Monitoring Line-Handler Process Status” (page 96)
• “Tracing a Communications Line” (page 98)
• “Recovery Operations for Communications Subsystems ” (page 98)
• “Related Reading for Communications Subsystems” (page 99)
When to Use This Chapter
Use this chapter to determine where to find more information about monitoring and recovery
operations for communications devices such as ServerNet adapters, CLIMs, printers, and spoolers;
communications lines; and communications processes such as CIP processes and WAN IOPs.
Communications Subsystems
The software that provides users of NonStop systems with access to a set of communications services
is called a communications subsystem. Because connectivity is an important part of online transaction
processing (OLTP), HP offers a variety of communications products that support a wide range of
applications.
Communication between specific devices or networks is typically achieved using several
communications products or subsystems. These products are related as components in a layered
structure. To accomplish the required connection, higher-level components—for example, NonStop
TCP/IP processes—use the services of lower-level components such as the ServerNet LAN Systems
Access (SLSA) subsystem. The CIP subsystem does not use the SLSA subsystem.
The same higher-level component can often use any of several lower-level components; thus, the
Expand subsystem—which consists of multiple processes on a node—can use the NonStop TCP/IP
subsystem, the CIP subsystem, the X.25 Access Method (X.25 AM), or other communication interface
options to provide data transmissions over local area networks (LANs) or wide area networks
(WANs). Similarly, multiple higher-level components can use the services of a single lower-level
component.
Local Area Networks (LANs) and Wide Area Networks (WANs)
Two important communications interfaces for LANs and WANs on NonStop systems are the SLSA
subsystem and the WAN subsystem.
The SLSA subsystem supports parallel LAN I/O operations, allowing NonStop NS-series systems
and NonStop BladeSystems to communicate across the ServerNet fabrics and access Ethernet
When to Use This Chapter 85