Expand Configuration and Management Manual (G06.24+)

Glossary
Expand Configuration and Management Manual—523347-008
Glossary-8
High-Level Data Link Control (HDLC) Extended
Mode protocol
High-Level Data Link Control (HDLC) Extended Mode protocol. The protocol used by
the satellite-connect line-handler process. Unlike the HDLC Normal protocol
implemented by direct-connect Expand line-handler processes, the HDLC Extended
Mode protocol uses the maximum window size of 61 frames (the maximum number of
outstanding frames before an acknowledgment is required) and implements the
selective reject feature. Selective reject causes only frames that arrive in error to be
retransmitted. See also High-Level Data Link Control (HDLC) Normal protocol.
High-Level Data Link Control (HDLC) Normal protocol. The protocol used by the direct-
connect line-handler process. The direct-connect line-handler process is provided for
use with conventional voice-grade leased-line and switched-line facilities, private
facilities, and fractional Transmission Group 1 (T1) facilities. See also High-Level Data
Link Control (HDLC) Extended Mode protocol.
hop count (HC). The number of intervening nodes on a route. HC is used to determine the
best path route: if two alternative routes have the same time factor (TF), the route with
the lowest HC is the best route. See also best-path route and time factor (TF).
HP NonStop Kernel. The operating system, which consists of the NonStop™ Kernel and a
set of services. The operating system does not include any application program
interface (APIs).
HP NonStop TCP/IP process. A NonStop TCP/IP subsystem process that provides a
Guardian file-system interface to the Transmission Control Protocol (TCP) and the
User Datagram Protocol (UDP). The Expand-over-IP line-handler process uses the
UDP services provided by a NonStop TCP/IP process to transmit data across an
Internet Protocol (IP) network. See also Transmission Control Protocol (TCP) and User
Datagram Protocol (UDP).
IEEE 802.3 protocol. Institute of Electronics Engineers (IEEE) standard defining the
hardware layer and transport layer of (a variant of) Ethernet.
input/output (I/O). (1) Data entered or transmitted out of a computer. (2) The process of
entering data into or transmitting data out of a computer.
Input/Output adapter module (IOAM). A product that allows the HP NonStop™ S-series
server to communicate with fiber-channel or Ethernet products. The IOAM is a rack-
mountable enclosure that contains two ServerNet Switch Boards and up to 5 Fibre-
Channel ServerNet adapters (FCSAs) or Gigabit Ethernet 4-port ServerNet adapters
(G4SAs). Up to 5 G4SAs, FCSAs, or any combination can be added per IOAM module,
for a total of 10 adapters per IOAM enclosure.
input/output process (IOP). A running program (part of the operating system) that
manages the I/O functions for one or more ServerNet addressable controllers (SACs)
of the same type.
Internet Protocol (IP). The Internet standard protocol that defines the Internet datagram as
the unit of information passed across the Internet and that provides the basis for the
Internet connectionless, best-effort packet-delivery service.