Expand Configuration and Management Manual (G06.24+)

Glossary
Expand Configuration and Management Manual—523347-008
Glossary-9
Internet Protocol (IP) address
Internet Protocol (IP) address. A 4-octet (32-bit) numeric value identifying a particular
network (network address portion) and a local host on that network (local address
portion). See also port number.
IOAM. See Input/Output adapter module (IOAM).
IOP. See input/output process (IOP).
IP. See Internet Protocol (IP).
IP address. An address that identifies a specific host to the Internet Protocol (IP). An IP
address consists of two parts: a network address, which identifies the network, and a
local address, which identifies a host within a network. A network address is
concatenated with a host address to form the IP address and uniquely identify a host
within a network. IP routes data between source and destination IP addresses.
Kernel subsystem manager process. A generic process named $ZZKRN that starts and
manages other generic processes, some system attributes, and the ServerNet X- and
Y-fabrics.
Layer 2. A term that is used to refer to the Data Link Layer of the Open Systems
Interconnection (OSI) Reference Model. Layer 2 defines rules for transmission on the
physical medium. Direct-connect and satellite-connect Expand line-handler processes
provide the High-level Data Link (HDLC) protocol at Layer 2. Expand-over-NAM line-
handler processes use the Layer 2 services provided by either the SNAX/APN or
X25AM subsystems. Expand-over-ServerNet line-handler processes use the Layer 2
services provided by the ServerNet monitor process, $ZZSCL. Expand-over-FOX line-
handler processes use the Layer 2 services provided by the FOX monitor process,
$ZZFOX. Expand-over-IP line-handler processes use the Layer 2 services provided by
NETIP protocol. Expand-over-ATM line-handler processes use the Layer 2 services
provided by the NETATM protocol. The Expand line-handler process’s Data Link Layer,
or line functions, corresponds to the LINE object referred to by the Expand Subsystem
Control Facility (SCF) interface.
Layer 3. A term that is used to refer to the Network Layer of the Open Systems
Interconnection (OSI) Reference Model. Layer 3 governs the switching and routing of
information between systems in the network and is responsible for error checking and
recovery. The Expand line-handler process’s Network Layer, or path functions,
corresponds to the PATH object referred to by the Expand Subsystem Control Facility
(SCF) interface.
Layer 4. A term that is used to refer to the Transport Layer of the Open Systems
Interconnection (OSI) Reference Model. Layer 4 accepts data from the OSI Session
Layer (Layer 5) and passes it to the OSI Network Layer (Layer 3). Layer 4 provides
end-to-end data integrity between processes and checks that messages received are
correct. The Expand line-handler process’s Layer 4, or path functions, corresponds to
the PATH object referred to by the Expand Subsystem Control Facility (SCF) interface.