Technical data

nslookup
The Compaq TCP/IP Services for OpenVMS utility that allows you to interactively
query domain name servers (BIND servers) and helps you set up and manage the
BIND server software.
NTP
See Network Time Protocol.
NTP packet
A message sent over the network that conforms to the Network Time
Protocol
format. This format includes space for recording the current ti
me. See also poll.
null modem
A simple form of modem connection in which only the data interchange circuits,
not the modem control circuits, are used.
occluded mounting
A TCP/IP Services/NFS method of mounting an NFS file system onto a client
mount point that is higher or lower in the directory structure than an active mount.
octet
A single, 8-bit unit of data. A networking term used instead of the term byte
because some systems have bytes that are not 8 bits long.
ODS-2diskstructure
An OpenVMS On-Disk Structure. This is the default disk structure of the
OpenVMS operating system.
ODS-5 disk structure (Alpha only)
An OpenVMS On-Disk Structure that is an extension to the existing ODS-2 disk
structure. It adds the ability to use extended file names that can be more easily
mapped between Windows and OpenVMS. ODS-5 expands the available character
set and filename length to be consistent with Windows 95 and Windows NT. ODS-5
also supports deeper directories.
On-Disk Structure (ODS)
A logical structure given to information stored on a disk or CD-ROM. ODS is a
hierarchical organization of files, their data, and the directories needed to gain
access to them. The OpenVMS file system implements the On-Disk Structure and
provides access control to the files located on the disk.
OPCOM
See operator communication manager.
OPCOM messages
Messages broadcast by the operator communication manager (OPCOM). These
messages are displayed on operator terminals and written to the operator log file.
The messages might be general messages that you send, user requests, operator
replies, or system events.
OPCOM process
The system process that manages operator communication manager (OPCOM)
operations.
open network
A network made up of nonproprietary, interoperable systems.
open network computing (ONC) remote procedure call (RPC)
An easy and popular paradigm for implementing the client/server model of
distributed computing. In general, the local system (client) sends a request to
Glossary–31