TCP/IP Configuration and Management Manual

Glossary
TCP/IP Configuration and Management Manual—427132-004
Glossary-7
Gateway to Gateway Protocol
any machine that transfers information from one network to another, as in “mail
gateway.”
Gateway to Gateway Protocol. The protocol core gateways used to exchange routing
information, GGP implements a distributed shortest path routing computation. Under
normal circumstances, all GGP participants reach a steady state in which the routing
information at all gateways agrees.
G4SA. See Gigabit Ethernet 4-Port ServerNet adapter (G4SA).
GESA. See Gigabit Ethernet ServerNet adapter (GESA).
GGP. See Gateway to Gateway Protocol.
Gigabit Ethernet 4-Port ServerNet adapter (G4SA). A multiport ServerNet adapter that
provides 1000 megabits/second (Mbps) data transfer rates between HP
NonStop S-series systems, Integrity NonStop servers and Ethernet LANs. The G4SA is
the only LAN adapter supported for the I/O Adapter Module (IOAM) enclosure, and it is
installed in slots 1, 2, 3, 4, and 5 of an IOAM. Although the G4SA supersedes the
Ethernet 4 ServerNet adapter (E4SA), Fast Ethernet ServerNet adapter (FESA), and
the Gigabit Ethernet ServerNet adapter (GESA), it cannot be installed in an HP
NonStop S-series enclosure.
Gigabit Ethernet ServerNet adapter (GESA). The GESA is a CRU that supports one
Ethernet connection and communicates with multiple processors through its dual
ServerNet interfaces to the ServerNet fabrics. The adapter exists in copper and fiber
versions. The copper version allows switchable or negotiated speeds; the fiber version
operates only at 1000 Mbps.
half-duplex mode. The communications mode in which data can be transferred in both
directions, but only in one direction at a time, and in which the direction of data flow
alternates. In the Session Layer, the data token indicates which side can send data.
header. The initial part of an SPI message. The first word of this header always contains the
value -28; the remainder of the header contains descriptive information about the SPI
message, most of which is accessible as header tokens. The tokens in an SPI
message header differ according to the type of message: the header of a message that
contains a command or response differs somewhat from the header of an event
message. An application can use SSGET or EMSGET calls to retrieve the values of
header tokens, and can use SSPUT calls to change the values of some tokens.
However, there are certain basic differences between header tokens and other tokens.
See also header token
.
header token. In an SPI message, a token that provides information pertaining to the
message as a whole. Header tokens differ from other tokens in several ways: they
exist in the buffer at initialization and their values are usually set by SSINIT, they can
occur only once in a buffer, they are never enclosed in a list, they cannot be moved to
another buffer with SSMOVE, and programs cannot position to them or retrieve their
values using the NEXTCODE or NEXTTOKEN operation. Programs retrieve the values