ServerNet Cluster 6780 Operations Guide (G06.28+, H06.05+)

Glossary
ServerNet Cluster 6780 Operations Guide—525606-003
Glossary-12
in-band control (IBC)
kilometers. The maximum number of hosts is 1024. The maximum packet size is 1518
bytes.
in-band control (IBC). A symbol-based communications protocol for communicating
management information across a ServerNet link without interfering with any
application traffic in the network. In ServerNet II, IBC traffic is via standard ServerNet
packets. ServerNet I used the Illegal Symbol variation of IBC. This technique uses a
subset of the available symbols to convey control information from one node to
another. The symbol subset chosen is from the group of symbols that are not for
passing data; these symbols are usually considered illegal or unused.
incident report. A report sent by the OSM software to the OSM Notification Director If
remote notification (dial-out) is configured, the OSM Notification Director forwards
incident reports to a service provider. The three types of incident reports are problem
incident reports, periodic incident reports, and software configuration incident reports.
input/output process (IOP). A running program (part of the NonStop Kernel operating
system) that manages the I/O functions for one or more ServerNet addressable
controllers (SACs) of the same type.
internal routing. The routing of packets within a NonStop S-series server. See also external
routing.
internal ServerNet X or Y fabric. The X or Y fabric that links ServerNet devices within a
NonStop S-series server. See also external ServerNet X or Y fabric.
Internet protocol (IP). A data communications protocol that handles the routing of data
through a network, which typically consists of many different subnetworks. IP is
connectionless; it routes data from a source address to a destination address. See also
IP address.
interprocessor communication (IPC). The exchange of messages between processors in
the same system or node.
I/O enclosure. A NonStop S-series system enclosure containing one module, which
includes ServerNet adapters, disk drives, components related to the ServerNet fabrics,
and components related to electrical power and cooling for the enclosure. An I/O
enclosure is identical to a processor enclosure except that it contains I/O multifunction
(IOMF) CRUs instead of processor multifunction (PMF) CRUs.
IOMF CRU. See I/O multifunction (IOMF) CRU.
I/O multifunction (IOMF) CRU. (1) A NonStop S-series customer-replaceable unit (CRU)
that connects an I/O enclosure to a processor enclosure through a ServerNet cable
and supplies power to the components within the IOMF CRU as well as redundantly to
the disk drives, SCSI terminators, and ServerNet adapters in that enclosure. The IOMF
CRU contains a power supply, a service processor (SP), a ServerNet router, an
Ethernet controller, an external ServerNet port, and three SCSI ServerNet addressable