Expand Configuration and Management Manual (G06.24+)

Subsystem Description
Expand Configuration and Management Manual—523347-008
18-6
Expand Line-Handler Processes
Expand-over-ServerNet line-handler process uses the NETNAM protocol to access the
NAM interface of the ServerNet cluster monitor process ($ZZSCL).
The Expand-over-ServerNet line-handler process manages security-related messages
and forwards packets outside the ServerNet cluster. Other messages, such as
incoming and outgoing data, usually bypass the Expand-over-ServerNet line-handler
process and are handled directly by the ServerNet fabrics and the NonStop cluster
switches; the Expand software is not involved.
Expand-Over-FOX Line-Handler Process
The Expand-over-FOX line-handler process uses a pair of ServerNet/Fiber eXtension
(ServerNet/FX) adapters, fiber-optic cables, the FOX monitor process ($ZZFOX), and
the FOX driver to connect to a FOX ring.
One ServerNet/FX adapter is connected through the ServerNet system area network
(ServerNet SAN) to the X-ring and a second ServerNet/FX adapter is connected
through the ServerNet SAN to the Y-ring. $ZZFOX is a generic process that is
responsible for maintaining configuration information about the FOX ring and is the
manager process for the ServerNet/FX adapters. The Expand-over-FOX line-handler
process uses the NETNAM protocol to access the NAM interface of $ZZFOX.
The FOX driver is responsible for communicating directly with the ServerNet/FX
adapters. It is provided as part of the NonStop Kernel operating system. The Expand-
over-FOX line-handler process manages security-related messages and forwards
packets outside the FOX ring. Other messages, such as incoming and outgoing data,
usually bypass the Expand-over-FOX line-handler process and are handled directly by
the ServerNet fabrics and the ServerNet/FX adapters; the Expand software is not
involved.
Expand-Over-ATM Line-Handler Process
The Expand-over-ATM line-handler process uses the Asynchronous Transfer Mode
(ATM) subsystem to provide connectivity to an ATM network. The Expand-over-ATM
line-handler process communicates with the ATM subsystem through the shared
memory of the QIO subsystem.
The ATM subsystem, which is HP’s implementation of the ATM protocol, consists of
hardware and software components that reside on a NonStop S-series server. The
ATM 3 ServerNet adapter (ATM3SA) provides one bidirectional full-duplex ATM OC3
port for connection to the User-Network Interface (UNI). The Expand-over-ATM line-
handler process uses the services provided by the ATM subsystem to transmit data
across an ATM network.
Note. For more information about the Expand-to-NAM interface, refer to Expand-to-NAM
Interface on page 18-49.
Note. For more information about the Expand-to-NAM interface, refer to Expand-to-NAM
Interface on page 18-49.