NonStop S-Series Operations Guide (G06.24+)

Communications Subsystems: Monitoring and
Recovery
HP NonStop S-Series Operations Guide—522459-007
6-2
Communications Subsystems
Communications Subsystems
The software that provides users of NonStop S-series 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 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 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), respectively. 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 S-series
servers are the SLSA subsystem and the WAN subsystem.
The SLSA subsystem supports parallel LAN I/O operations, allowing NonStop S-series
servers to communicate across the ServerNet fabrics and access Ethernet devices
through various LAN protocols. SLSA also communicates with the appropriate adapter
type over the ServerNet fabrics. Supported adapters include:
•
ATM 3 ServerNet adapter (ATM3SA)
•
Ethernet 4 ServerNet adapter (E4SA)
•
Fast Ethernet ServerNet adapter (FESA)
•
Gigabit Ethernet ServerNet adapter (GESA)
•
Multifunction I/O board (MFIOB) in the processor multifunction (PMF) customer-
replaceable unit (CRU) and I/O multifunction (IOMF) CRU
•
Token-Ring ServerNet adapter (TRSA)
In addition to the adapters, the SLSA subsystem also supports these objects:
•
Processes
•
Monitors
•
ServerNet addressable controllers (SACs)
•
Logical interfaces (LIFs)
•
Filters
•
Physical interfaces (PIFs)